path neuro formatted Flashcards

Question

16. 23.02.74 CNS features NOT typical of TB are ? 1. basal meningeal enhancement 2. 4cm focal mass 3. irregularity of vessels

Answer 1

all are feature of TB haha ADB-->Original question from G drive 16. 23.02.74 CNS features NOT typical of TB are ? 1. basal meningeal enhancement 2. 4cm focal mass 3. irregularity of vessels 4. hydrocephalus 5. degeneration of central portion/body of corpus callous (false)

Answer 2

Answer: Spinal cord STATDX: common locations - basal ganglia - Thalami - corticomedullary junctions - cerebellum

Answer 3

NSWER: 2. Cerebellar vermis - F 16. Multiple sclerosis, least common site (TW)A 1. Cerebellar white matter - T - cerebellar peduncles are classic. 2. Cerebellar vermis - F 3. Corpus callosum - T - typically mutliple perpendicular callososeptal T2 hyperintensities. 4. Perivenular - T - perpendicular lesions in perivenular distribution. >85% lesions periventricular / perivenous. 50-90% callososeptal interface. Perivenular extnsion "Dawson finger" along path of deep medullary veins.

Answer 4

**RY - correct answer is actually 4. a subacute presentation is recognized in a subset of individuals. Clinical manifestations include weakness, lethargy, ataxia, seizures - directly from Big Robbins pg 1276 (prior favoured answer was 3) 17. 23.03.07 In HSV I encephalitis which is TRUE Rob p828-829 1. Age 50-70 years (most common in children and young adults) 2. Typically involves superior frontal lobes (predilection for the limbic system (temporal lobes, cingulate gyri, subfrontal region)) 3. Commonest presentation is headache (alterations in mood,memory and behavior is most common presentation) 4. A subacute presentation with ataxia and seizures is recognized 5. Oncocytic intracytoplasmic inclusions (Cowdry Intranuclear inclusion bodies) SCS: two types. Cowdry A: HSV, B: CMV

Answer 5

2. post obstetric patient - T - think this is most correct. **LJS - 30-40% SLE pt have antiphospholipid Ab = recurrent arterial and venous thrombosis. ?higher risk than post-partum ***LW: 2019 consensus statement states 5-17% of cerebral venous infarction / thrombosis have SLE related conditions, while 1% to 59% are peri partum and 54% to 71% of cases are on OCP. So i still favour post obstetric patient as most correct option. (https://www.ahajournals.org/doi/10.1161/STROKEAHA.119.025334) 17. Most at risk for cerebral venous infarction (TW) ANSWER: 2 1. diabetic in renal failure 2. post obstetric patient - T - think this is most correct. 3. young girl on progesterone only pill - F - oestrogen is major prothrombotic component. Progesterone much lower risk. Most frequent risk factor for cerebral venous sinus thrombosis is the OCP (but this is presumably the oestrogen containing one). 4. young girl with SLE

Answer 6

*AJL - Agree with below. This is now called MSA-P (MSA with parkinsonian features). The other type of MSA is MSA-C (MSA with cerebellar symptoms/changes). 2. Shy Drager - T - known as multiple system atrophy. Sky-Drager syndrome still used sometimes for MSA when primary symptoms are autonomic failure. MSA - striatonigral degeneration is clinically similar to idiopathic PD in presentation, but is relatively resistent to L-dopa treatment (due to pattern of neuronal degeneration - ie both dopaminergic projections and its target neurons are absent, therefore L-dopa cannot bulster neurotransmission as occurs in parkinsons disease).

Answer 7

18. 23.02.22 Creutz-Jakob disease –what would be UNUSUAL finding ? Rob p830 Answer:2. Survival of 3-3½ years (uniformly fatal usually within 7 months) 1. Cortical atrophy is rarely found (brain appears grossly normal (no significant atrophy), as progression of dementia so rapid) 2. Survival of 3-3½ years (uniformly fatal usually within 7 months)

Answer 8

ANSWER: 11. Hydatid / echinococcus - T - large uni- or multilocular cyst +/- detached germinal membraine. Cyst fluid is opalescent. 18. Solitary 3cm cystic lesion in the brain containing an opaque gel-like substance (TW) ANSWER: 1. Hydatid / echinococcus - T - large uni- or multilocular cyst +/- detached germinal membraine. Cyst fluid is opalescent. 2. Cysticercosis - F - although most common parasitic infection world wide, cyst size is variable and typically 1cm, with range of 4-20mm. Parenchymal cysts 1cm or less, however subarachnoid systs may be larger, up to 9cm reported (and recemose). Cysts are ovoid and white-to-opalescnet, rarely exceeding 1.5cm. Contain an invaginated scolex with hooklets that are bathed in clear cyst fluid. 3. Amoebiasis - F - cerebral amebiasis is a rare cause of brain abscess. Amebic encephalitits - hyperintense lesions +/- haemorrhage. 4. Strongyloides - F 5. Ascaris - F

Answer 9

ANSWER:b. Toxoplasmosis - T- most common cause of focal lesion in HIV+. 18. HIV positive patient with CD4 count less than 100 has a mass on CT brain. What is the likely diagnosis? (TW) a. Lymphoma - F - less likely, although increased risk with immunosuppression. b. Toxoplasmosis - T- most common cause of focal lesion in HIV+. c. Cryptosporidium - F - less likely cf toxoplasmosis d. TB - F - less likely e. PML - F - diffuse/patchy WM abnormalities.

Answer 10

incomplete questionRobins: 1308 The histologic appearance of glioblastoma is similar to anaplastic astrocytoma with the additional features of necrosis and vascular/endothelial cell proliferation.Necrosis in glioblastoma often occurs in a serpentine pattern in areas of hypercellularity.Tumor cells collect along the edges of the necrotic regions, producing a histologic pattern referred to as pseudo-palisadingThe vascular cell prolif- eration produces tufts of cells that pile up and bulge into thelumen; the minimal criterion for this feature is a double layer of endothelial cells. With marked vascular cell proliferation the tuft forms a ball-like structure, the glomeruloid body. VEGF, pro- duced by malignant astrocytes in response to hypoxia, contrib- utes to this distinctive vascular change. Since histologic features can be extremely variable from one region to another, small biopsy specimens may not be representative of the entire tumor.

Answer 11

Answer: Osteosarcoma RADIOPAEDIA: Assoicated neoplasms - Pheochromocytoma - Wilms tumour - Renal agniomyolipoma - Rhadbomyosarcoma - Leiomyosarcoma - Glimoa: JPA, optic nerve, diffuse brainstem, spinal astrocytoma - ganglioglioma - MPNST - Carcinoid - Leukaemia

Answer 12

4. 15% malignant - ?T - in the literature the percentage of the anaplastic variant ranges from 7-89% (Med and Ped Onc: 1998 30:6 p319). 2) ependymoma in the pediatric patient (TW) 1. supratentorial location - F - infratentorial 70% (floor 4th ventricle). Can also occur supratentorial: frontal > parietal > temporoparietal > juxtaventricular. 2. homogenous enhancement - F - variable heterogeneous enhancement. 3. hemorrhage is common - F - intratumoral haemorrhage 10% 4. 15% malignant - ?T - in the literature the percentage of the anaplastic variant ranges from 7-89% (Med and Ped Onc: 1998 30:6 p319). 5. arise from lumbar nerve roots in the spine - F - arise form ependymal cells lining the central canal.

Answer 13

Answer:2. Glioblastoma multiforme Usually large, heterogenous masses with central necrosis, thick, irregular “shaggy” walls, and increased vascularity with haemorrhage • Marked mass effect & oedema • Often find varying degrees of anaplasia within the same tumour ∴biopsy can be misleading 2. 84.APRIL02 + APRIL2004 Necrosis is a characteristic feature of 1. Pilocytic astrocytoma 2. Glioblastoma multiforme 3. Acoustic schwannoma 4. Craniopharyngioma 5. Ependymoma

Answer 14

2. Detectable at angiography F - most are angiographically occult due to slow flow. 2. Cavernous angiomas, which is not typical: (GC) 1. Detectable at angiography F - most are angiographically occult due to slow flow. 2. Bleeding tendency T - nearly all show evidence of recent and remote hemorrhage, as suggested by the presence of hemosiderin-laden macrophages, cholesterol crystals, and hemosiderin-stained parenchymal tissues. 3. No intervening normal brain T - this is the only histopathologic characteristic that distinguishes these lesions from capillary telangiectasias. 4. Associated venous angioma T - persistent elevations in venous pressures, as may be seen locally within a venous malformation, may promote a pathologic reactive angiogenesis or angiogenic proliferation, resulting in abnormal blood vessel growth and coalescence. Note that it is the immaturity of the blood vessels within the cavernoma that differentiates it from a venous angioma (which consists of mature vessels responsible for normal venous drainage). 5. Pseudocapsule T - clots and blood products of various stages of evolution within the lesion, as well as calcification and gliosis surround the cavernoma, creating the appearance of a pseudocapsule. (eMedicine)

Answer 15

ANSWER:2. Affects the putamen and caudate T - degeneration of the striatum (C&P). 2. Huntington's disease, which is true: (GC) 1. Autosomal recessive F - autosomal dominant disorder 2. Affects the putamen and caudate T - degeneration of the striatum (C&P). 3. Presents in the second decade F - age of onset most commonly in 4th and 5th decades, related to the length of the CAG repeat. 4. Chorea due to striatal excitation F - loss of striatal inhibitory output, from the degeneration of GABA-containing neurons. This leads to disregulation of the basal ganglia that normally modulate motor output.

Answer 16

Answer: Pontine myelinosis, midbrain, and supratentorial changes aka "Osmotic demyelination syndrome. Osmotic Demyelination syndrome - recent term replacing CPM, recognising that extrapontine structures can also be affected. j - includes CPM and extrapontine myelinolysis. - has a biphasic pattern. - 1s phase is usually attributable to the electrolyte abnormality. 2nd phase follows rapid reversal of the abnormality progressing to classic osmotic demyelination syndrome. - when pontine involvement is prominent, clinical features consist of: --> spastic quadriparesis --> pseudo bulbar palsy --> changes in levels of consciousness --> coma --> death THIAMINE DEFICIENCY - causes Wernicke encephalopathy. - characterised by combination of psychotic symptoms and ophthalmoplegia. - characterised by foci of haemorrhage and necrosis in the maxillary bodies and the walls of the 3rd and 4th ventricles. VITAMINE B12 Deficiency - Causes subacute combined degeneration of the spinal cord - affects both ascending and descending spinal tracts. - presents with bilateral symmetrical numbness, tingling, and slight ataxia int he lower extremities.

Answer 17

1. Hippocampus 2. Least likely site for hypertensive bleed in the brain is: (GC) 1. Hippocampus T 2. Cerebellum F - 10%; behave like SOL's - herniation & obstructive hydrocephalus. 3. Basal ganglia F - with thalamus account for 65% of hypertensive bleeds 4. Thalamus F - see above 5. Brainstem F - 10%

Answer 18

Answer: Multipolar cells with micro cysts and bipolar cells with Rosenthal Fibers FROM ROBBINS: Pilocytic astroctyomas - WHO I - Children/young adults - located in cerebellum (60%), optic nerves (25-30%), floor/walls 3rd ventricles, cerebral hemispheres. - rarity of TP53 mutations - NF1 association - Large cystic component with enhancing mural nodule (67%) - Completely solid (17%). Heterogenous mixed cystic/solid (16%) - Tumors often biphasic, microcytic and fibrillary areas. Contain bipolar cells with GFAP positive processes, Rosenthal fibres, eosinophilic granular bodies. - 5-10 year survival rate >95%

Answer 19

Answer: usually slow growing and asymptomatic Robbins Subependymomas are solid, sometimes calcified, slow-growind nodules attached to the ventricular lining and protrued into the ventricle. Usually asymptomatic, incidental finding on autopsy/imaging. Most often found in lateral and 4th ventricles. Radiopaedia - 4th ventricle (50-60%) - lateral ventricles, usually frontal horns (30-40%) - 3rd ventricle (rare) - central canal (rare).

Answer 20

1. Type 2 neurofibromatosis is associated with multiple schwannomas – T – MISME, multiple inherited schwannomas, meningiomas, Ependymoma. 2. The following are true in relation to cerebello-pontine angle tumours:¬ (TW) 1. Type 2 neurofibromatosis is associated with multiple schwannomas – T – MISME, multiple inherited schwannomas, meningiomas, Ependymoma. 2. Acoustic neuromas are typically hyperintense on TI weighted images – F – intermediate signal most common. High signal patches if rare haemorrhagic lesion present. 3. Peripheral enhancement is a feature of epidermoid cysts – F – no enhancement is the rule, however sometimes the margin of cyst minimally enhances CECT. Mild peripheral enhancement occurs in approx 25% cases. Osborn. 4. Choroid plexus seen in the cerebello-pontine angle is not a normal feature – F – choroid plexus may normally pass from 4th ventricle through foramen of Luschka in to CPA cistern. Osborn. 5. Acoustic neuromas arise from the cochlear portion of the acoustic nerve – F – arise from the vestibular segment of CN VIII, with an equal frequency b/w superior and inferior vestibular nerves. Cochlear nerve involvement is much less common (15% vs 85%).

Answer 21

1. Fourth ventricle in children and spine in adults

Answer 22

ANSWER: 11. Pick's disease - focal cortical atrophy of anterior frontal and anterior temporal lobes 20. White matter disease, least likely: (GC) ANSWER: 11. Pick's disease - focal cortical atrophy of anterior frontal and anterior temporal lobes. 2. ADEM 3. DAI

Answer 23

(Most commonly superficial and supratentorial (temporal > frontal > parietal))

Answer 24

5. 4 year survival 50% F - current 5YS rate for patients with intracranial ependymomas is approximately 50%, when rates from children and adults are combined. Stratification based on age reveals 5YS rates of 76% in adults and only 14% in children. 21. Children with Ependymoma, which is false: (GC) 1. Prognosis poor – cannot remove completely T - Despite the survival advantage of gross total resection, lesions of the posterior fossa are in close proximity to cranial nerves with a significant risk of long-term neurologic dysfunction and disability. Hence, most tumors of the posterior fossa cannot be fully resected and are likely to recur without postoperative radiation. 2. Less common than medulloblastoma T - third most common paediatric brain tumour, after medulloblastoma & JPA. 3. Does not metastasize as frequently as medulloblastoma T - subarachnoid dissemination via CSF rare, observed in <10% of patients at diagnosis when ependymoblastomas are excluded. The incidence is higher with infratentorial ependymomas than with supratentorial tumors (9% vs 1.6%). 4. Myxopapillary variant in filum terminale T - considered a biologically and morphologically distinct variant of ependymoma, occurring almost exclusively in the region of the cauda equina and behaving in a more benign fashion than grade II ependymoma. 5. 4 year survival 50% F - current 5YS rate for patients with intracranial ependymomas is approximately 50%, when rates from children and adults are combined. Stratification based on age reveals 5YS rates of 76% in adults and only 14% in children.

Answer 25

Answer: Intra-axial position (least correct). ROBBINS - Typical meningiomas are WHO I - The presence of brain invasion is associated with increase risk of recurrence, but does not alter the histologic grade of the lesion. Histologic Variants - WHO I: Syncytial, fibroplastic, transitional, psammomatous, secretory, microcystic - WHO II: clear cell, chordoid. - WHO III: papillary, rhabdoid.

Answer 26

1. Metachromic leukodystrophy T - progressive symmetrical areas of T2 hyperintensity, (confluent "butterfly-shaped" PVWM change), early sparing of the subcortical U-fibres. Late onset form (after puberty-4th decade) may manifest as pychiatric/behavioural OR CNS motor signs + peripheral neuropathy. Other forms: late infantile (6m-3yo, death in 5yrs), juvenile (4-12yo, slower progressn). 23. 15yo with psychosis, MRI showed diffuse WM abnormality, which is most likely: (GC) 1. Metachromic leukodystrophy T - progressive symmetrical areas of T2 hyperintensity, (confluent "butterfly-shaped" PVWM change), early sparing of the subcortical U-fibres. Late onset form (after puberty-4th decade) may manifest as pychiatric/behavioural OR CNS motor signs + peripheral neuropathy. Other forms: late infantile (6m-3yo, death in 5yrs), juvenile (4-12yo, slower progressn). 2. ADEM F - multifocal punctate or large confluent areas of T2/FLAIR hyperintensity. 3. Huntington’s F - caudate nucleus atrophy. 4. HIV F - AIDS-dementia complex: cerebral atrophy, subtly increased SI on T2/FLAIR without mass effect (from leaky capillaries), may be focal/diffuse, symmetric/asymmetric, reversible/nonreversible. Symptoms are more of inattention, indifference and psychomotor slowing (progressing to frank dementia), i.e. not psychosis.

Answer 27

4. Beri-beri heart disease this is caused by vit B1 (Thiamine) deficiency can cause acute heart failure with decreased LV systolic function and enlargement +/-

Answer 28

*LW: Correct terminology is osmotic demyelination syndrome / osmotic myelinolysis; which is a global term of both central pontine and extra pontine myelinolysis. Central pontine myelinolysis clinical features: dysarthria and dysphagia (secondary to corticobulbar fibre involvement), a flaccid quadriparesis (from corticospinal tract involvement) which later becomes spastic, all from involvement of the basis pontis. if the lesion extends into the tegmentum of the pons - pupillary, oculomotor abnormalities may occur. There may be an apparent change in conscious level reflecting the “locked-in syndrome” that a large lesion in this site is particularly liable to produce. Extra pontine myelinolysis clinical features: Movement disorders Mutism, parkinsonism, dystonia, and catatonia 1. Central pontine myelinolysis

Answer 29

2. Caudate nucleus + putamen T - striking atrophy (heart or box-shaped frontal horns), less dramatic change in the putamen. 24. Huntington’s chorea, what does it show: (GC) 1. Various locations including basal ganglia F - although the globus pallidus may secondarily atrophy, with dilatation of the lateral and third ventricles. 2. Caudate nucleus + putamen T - striking atrophy (heart or box-shaped frontal horns), less dramatic change in the putamen. 3. Cerebellum F 4. Locus ceruleus F - involved in Parkinson's disease.

Answer 30

1. Shy Drager Syndrome SCS: Radiopaedia. Option 1, 3 and 4 all come under the umbrella of multisystem atropy (MSA), but are old terms superceded by MSA-C and -S - Shy Drager synd: when autonomic symptoms predominate (now abandoned) -Striatonigral degeneration: shows predominant Parkinsons features (Now known as MSA-P) - Olivopontocerebellar atrophy: cerebellar dysfunction dominates (now known as MSA-C = hot cross bun sign • Parkinsonism with autonomic system failure, often manifesting as orthostatic hypotension o orthostatic hypotension o urinary incontinence o inability to sweat • Loss of neurones from intermediolateral column of spinal cord o explains sympathetic dysfunction • May be similar pathologically to Parkinson disease (Lewy bodies) or striatonigral degeneration (widespread neuronal loss) • Shy Drager Syndrome • Multiple system atrophy with autonomic failure; is a progressive disorder of the central and autonomic nervous systems. The disorder is characterized by postural hypotension • There are 3 types of Shy-Drager syndrome: o Parkinsonian-type which may include symptoms of Parkinson's disease such as slow movement, stiff muscles, and mild tremors o cerebellar-type which may include problems such as loss of balance and the tendency to fall; and o combination-type

Answer 31

Answer: Hypothalamus Robbins - Usually located in the cerebellum, but may also appear in the floor and walls of the 3rd ventricle, optic nerves, and occasionally the cerebral hemispheres Statdx - NF1 individuals: Optic pathway - others: Cerebellum (60%) > hypothalamus, brainstem, cerebral hemispheres > optic pathway Radiopaedia - Cerebellum (60%) - Optic pathway (optic nerve, optic chiasm, hypothalamus, optic radiation), 25-30% particularly common in NF1 - Other less common locations including brainstem, cerebral hemispheres, cerebral ventricles

Answer 32

SCHWANNOMA - well-circumscribed, encapsulated masses, that abut the associated nerve without invading it. - comprised of an admixture of dense and loose areas referred to as ANTONI A and ANTONI B areas, respectively. - palisading of nuclei is common and "nuclear-free zones" that lie between regions of nuclear palisading are termed VEROCAY BODIES. - Within the cranial vault: most common location is CP angle. Other locations include trigeminal nerve and dorsal roots. - Extradural: large nerve trunks or as soft tissue lesions. - no risk for malignant transformation. - epidemiology: 5-6th decade. NF2. PLEXIFORM NEUROFIBROMA - neurofibromas are neoplastic Schwann cells admixed with perineurial-like cells, fibroblasts, mast cells, and CD34+ cells. - plexiform neurofibromas specifically: uncommon variant of neurofibromas. They grow within and expand nerve fascicles, entrapping associated axons - "bag of worm" appearance. - Unlike other neurofibroma types, plexiform neurofibromas are at significant risk of eventual malignant transformation (5-10%). - epidemiology: early childhood. sporadic or NF1-associated.

Answer 33

Answer: Ganglioneuroma FROM ROBBINS/RADIOPAEDIA/STATDX GANGLIONEUROMA - One of the tumors from the "Neuroblastic tumor family" which include ganglioneuroblastoma and neuroblastoma. - fully differentiated neuronal tumors derived from primordial neural crest cells that form the SNS. - Composed of ganglion and Schwann cells + fibrous tissues. - Age: 40% <1 year old, 35% 1-2 years old, 25% >2 year old. - presentation. Incidental finding. - Associations: MEN type IIB (particularly with mucosal ganglioneuromas. NEUROBLASTOMA - most important member of the "Neuroblastic tumor family" - Classically - composed of small primitive-appearing cells. - Typically, Rosettes (Homer-Wright pseduorosettes) can be found. - median age at diagnosis 18 months (40% diagnosed in infancy) - Mostly sporadic, 1-2% familial. - 60-80% of children present with stage 3 or stage 4 tumors. - IN childhood, 40% of neuroblastoma arise in the adrenal medulla. presents as large abdominal mass with fever and weight loss. - the remainder occur along the sympathetic chain - paravertebral abdomen (25%), posterior mediastinum (15%). GANGLIOMA - Neuronal tumor family. - most common of the neuronal tumors of the CNS - composed of mixture of mature neuronal and glial cells. - Typically superficial lesions that present with seizures. - 20% have BRAF mutation. NEUROFIBROMA - Each fascicle is infiltrated by neoplasm – not possible to separate lesion from nerve) SCHWANNOMA - most common in 5th to 6th decade except in NF-2)

Answer 34

2. Wilson’s - T - Onset of liver diease with WD usually 8-16yo, neurological symtpoms rare <12yo. WD often recognised in 2nd-3rd decade. M=F. Most common to see putamen (predilection for outer rim) and pons (dorsal and central regions) of increased T2. 27. 25 yo man with liver failure, previously had MRI showing increased signal in basal ganglia, most likely: (T bag, G bees) 1. HIV - F 2. Wilson’s - T - Onset of liver diease with WD usually 8-16yo, neurological symtpoms rare <12yo. WD often recognised in 2nd-3rd decade. M=F. Most common to see putamen (predilection for outer rim) and pons (dorsal and central regions) of increased T2. 3. Liver failure kernicterus - F - develops during the 1st year of birth (term and pre-terms). Kernicterus is the staining of the basal ganglia, brainstem, and cerebellum by unconjugated bilirubin: encephalopathy due to deposition of toxic unconjugated bilirubin. High signal T2 in globus pallidus or other areas of basal ganglia. Most common cause = erythroblastosis fetalis. 4. Disseminated toxoplasmosis - F

Answer 35

Answer: Lymphoma - primary FROM ROBBINS Primary CNS lymphoma is the most common CNS neoplasm in immunosuppressed individuals, including those with AID and immunosuppression after transplantation. Lymphoma arising outside the CNS rarely involves the brain parenchyma. FROM STATDX Post-transplant lymphoproliferative disease (PTLD) is a spectrum of abnormal lymphoproliferations resulting from trasnplantations Ranges from lymphoid hyperplasia to malignant lymphoma. Most common B-lymphocyte proliferation is associated with EBV infection. It is the most common malignancy in kidney transplant recipients after skin cancer. Renal transplant patients have a 35x increased risk of developing lymphoma. Most common site is the kidney graft. Retroperitoneum is the most common site of lymphadenopathy. Other sites include GI tract, liver, spleen, lung, head & neck - involvement in periventricular regions and subcortical white matter.

Answer 36

c. Papillary variant 28. Craniopharyngioma on histology in a 60 yo, solid 5cm, no cystic change or calcification: (GC) a. Review pathology: not usually solid tumours F - vary from solid to cystic. b. Sellar expansion but not destruction F - extensive sellar destruction in 75% of craniopharyngiomas c. Papillary variant T d. Absence of calcification is unusual F - only 30-40% contain Ca2+ in adults, cf. 90% of CP in children. Craniopharyngiomas arise from epithelial remnants of Rathke’s pouch that are trapped in pituitary stalk. Grows slowly and damages hypothalamus (causing endocrine abnormalities), compresses optic chiasm (causing bitemporal hemianopsia), blocks third ventricle (causing hydrocephalus). Histologically benign but frequently recurs due to incomplete excision; rarely metastasizes or transforms to squamous cell carcinoma. * Papillary subtype: usually occurs in older adults (50+). Histology: well-circumscribed, composed of cores of fibrovascular stroma lined by well-differentiated squamous epithelium that may separate to form pseudopapillae; resembles squamous papilloma; no stellate reticulum, no “wet” keratin, no calcification, no xanthogranulomatous inflammation; cystic fluid does not resemble motor oil. * Adamantinomatous subtype: usually children (5-14yrs), associated with beta-catenin mutations. 90% cystic, 90% calcifn. Histol: wet keratin, Ca2+, cysts with cholesterol (sump oil).[Path outlines]

Answer 37

Answer: Hypovolemic shock (least correct) Radiopaedia/Robbins - incidence of 1-3% following long bone fractures and 33% following bilateral long bone fractures - Sx: variable, headache, lethargy, irritability, deliuim, stupor, convulsions, coma - Can reach brain through right-left cardiac shunt or through intact pulmonary circulation. - A diffuse petechial rash (20-50% of cases) is related to rapid onset of thrombocytopenia.

Answer 38

Answer:4. Meningioma (Cystic or necrotic change may be present - most often in parasagittal tumours (3 – 14%)) 29. 23.03.84 Cystic tumour in brain LEAST LIKELY is ? 1. Haemangioblastoma (60% are cystic masses with mural nodule that usually abuts pial surface) 2. JPA (Cerebeallar JPA 30% of total of JPA - Well-circumscribed mass with large cyst, and small reddish-tan mural nodule) 3. PNET (commonly cystic) 4. Meningioma (Cystic or necrotic change may be present - most often in parasagittal tumours (3 – 14%)) 5. Schwannoma (cystic change is common) 6. DNET (Well-defined “pseudocystic” lesion (high water content)) BR 1348 – cystic changes are a common finding

Answer 39

4. History of rheumatic fever and tooth extraction T - Aneurysms that develop at distal sites in the intracranial circulation are often caused by trauma or infection. Mycotic aneurysms are most commonly due to infected arterial embolus, occurring in subacute bacterial endocarditis. In such cases, they are often multiple, being situated in small corticomeningeal branches of the cerebral artery. 29. Peripheral MCA aneurysm, most likely history: (GC) 1. SLE F - Commonly reported CNS vascular lesions with SLE include infarcts and transient ischemic attacks. Intracranial hemorrhages are present in approximately 10% of patients with CNS symptoms. Although uncommon, arteritic and nonvasculitic aneurysms occur in SLE. These can be saccular, fusiform, or a bizarre-looking mixture of both. 2. Past history of irradiation for fibrous dysplasia F - Radiation is contraindicated as it has been found to increase the rate of secondary malignancy by 400 times. If in the remote past... intracranial aneurysms may develop (and rupture) post irradiation. 3. Hypertension F - Charcot-Bouchard microaneurysms secondary to segmental lipohyalinosis of the walls of long penetrating arteries. 4. History of rheumatic fever and tooth extraction T - Aneurysms that develop at distal sites in the intracranial circulation are often caused by trauma or infection. Mycotic aneurysms are most commonly due to infected arterial embolus, occurring in subacute bacterial endocarditis. In such cases, they are often multiple, being situated in small corticomeningeal branches of the cerebral artery.

Answer 40

normal sella favours meningioma rather than macroadenoma - T - as pituitary MAs grow they first expand sella and then grow upwards. Aggresive adenomas extend inveriorly, invade sphenoid, and may destroy upper clivus. As they are soft - often are indented by diaphragma sellae giving them a 'snowman' configuration which can help Dx from meningoma. ) Sellar lesions, which is true (TW) 1. normal sella favours meningioma rather than macroadenoma - T - as pituitary MAs grow they first expand sella and then grow upwards. Aggresive adenomas extend inveriorly, invade sphenoid, and may destroy upper clivus. As they are soft - often are indented by diaphragma sellae giving them a 'snowman' configuration which can help Dx from meningoma. 2. squamous variant of craniopharyngioma is more likely cystic - F - squamous papillary type (more common in adults) rarely calcifies, often solid, isodense. Both adamantinomatous and squamous papillary types enhance. 3. intrasellar arachnoid cyst will displace stalk anteriorly - F - 10% arachnoid cysts are suprasellar & would push stalk back. 4. 17mm pituitary is normal for pregnant female - F - normal pituitary measurements: children 6mm, males and post-menopausal females 8mm, young menstruating females 10mm, pregnant/lactating females 12mm. 5. macroadenoma more likely to compress ICA than meningioma - F- meningioma more likely to compress / constrict ICA (given ICA course in cavernous sinus too). Note that macroadenomas can also extend into the cavernous sinus.

Answer 41

*LW: Difficult question, possibly poor recall given no perfect answer: Preferred options of DNET vs PXA 1) DNET: multicystic bubbly cortical mass, commonly temporal lobe 2) Pilocytic astrocytoma: enhancing nodule with associated cyst, rarely cortical. 3) Anaplastic Astrocytoma may cause solid appearing cortical mass, however anaplastic occur in adulthood mean age - 40-50yrs. 4) Mesial sclerosis: neronal loss and gliosis 5) Pleomorphic xanthoastrocytoma: cortical enhancing mass with adjacent cyst, temporal lobe most common, older children. Previous notes: i thin it is 3 or 5: in the absence of stated associated cystic component astrocytoma possible, while age argues against. However question states age and temporal lobe, thus PXA felt most likely.

Answer 42

Streptococci and staphylococci Nearly always caused by bacterial infections; direct implantation / local extension / haematogenous spread. 25% are cryptogenic. Predisposition: - diabetes - immunosuppressed - acute bacterial endocarditis (usu multiple), -cyanotic CHD (R-L shunt), chronic pulm sepsis. CSF: elevated white cell count and protein, normal glucose. Complications: - rupture with ventriculitis/meningitis - daughter abscesses - venous sinus thrombosis & infarction, - mass effect. [Robbins]

Answer 43

1. Detectable at angiography F - most are angiographically occult due to slow flow.

Answer 44

Answer: Ganglioneuroma NEUROBLASTIC TUMORS Includes tumors of the sympathetic ganglia and adrenal medulla that are derived from primordial neural crest cells populating these sites. Includes Neuroblastoma, ganglioneuroblastoma, and glanglioneuroma. Neuroblastoma - most important member of the family. - most common extra cranial solid tumor of childhood - 40% arise in the adrenal medulla. 25% paravertebral abdomen, 15% posterior mediastinum. - histology: undifferentiated high grade. small primitive cells with dark nuclei. Homer-wright pseudoroettes. Ganglioneuroblastoma - commonly attached to a nerve trunk or arise form the adrenal gland. - contains elements of both neuroblastoma and glanglioneuroma Ganglioneuroma - fully differentiated neuronal tumour without immature elements. - occur anywhere along the peripheral autonomic ganglion sites. - posterior paraspinal mediastinum is most commonest location (40%). - other locations include retroperitoneum, neck, and adrenal glands. - histology: neoplastic ganglion cells. Spindle-shaped Schwann cells are present in the background storm. PERIPHERAL NERVE SHEATH TUMORS (PNET) Benign and malignant neoplasms, majority composed of cells that show evidence of Schwann cell differentiation. These include: Schwannoma, neurofibroma, and malignant peripheral nerve sheath tumor (MPNST). Schwannoma - A component of NF2 (chromosome 22). - well circumscribed encapsulated assess that abut the associated nerve without invading it. - Composed of an admixture dense/loos areas i.e. Antoni A and Antoni B areas. - Palisading of nuclei is common, regions between are called Verocay Bodies - Immunohistochemical staining: S100+ - Within cranial vault: most common at CP angle (CNVIII). can affect CNV and dorsal roots) - Extradural: large nerve trunks or as soft tissue lesions without an identifiable associated nerve. Neurofibroma - Benign nerve sheath tumor, more heterogenous than schwannoma - contains neoplastic Schwann cells admixed with perineurial-like cells, fibroblasts, mast cells, and CD34+ spindle cells - A component of NF1 - Diffuse neurofibromas: plaque like elevation of skin - Plexiform neurofibromas: deep or superficial locations in association with nerve roots/large nerves. Malignant peripheral nerve sheet tumor (MPNST) - High grade tumors - half arise in NF1 patients, presumed malignant transformation of plexiform - "triton tumor" has focal areas with rhabdomyoblastic morphology. OTHER Ganglioglioma - F - tumor of neoplastic astrocytes (rarely oligodendrocytes) and ganglion cells.

Answer 45

Necrosis T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation 3. Which is the most important for diagnosis in GBM: (GC) 1. Necrosis T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation 2. Angiogenesis ? - microvascular proliferation is also a Dx feature 3. Cystic change F - non specific feature 4. Mitosis F - abnormal mitoses are also present in grade III (anaplastic) astrocytoma 5. Vasogenic oedema F - non specific feature WHO grading & Histological criteria: I Pilocytic astrocytoma - II Diffuse astrocytoma - 1 criterion, usually nuclear atypia III Anaplastic astrocytoma - 2 criteria, usually nuclear atypia and mitoses IV Glioblastoma - 3 criteria, usu nuclear atypia, mitoses, microvasc proliferation +/or necrosis

Answer 46

*LW: 3. ADEM - T 3. MS plaques that are not perpendicular to ventricles or some such (atypical anyway) (TW) 1. Type III, IV: Describes active plaques that are less well demarcated with widespread oligodendrocyte deposits (pattern 3) and are note centered on vessels with central only oligodendeocyte deposits (pattern 4). Pattern 1 - active plaque sharply demarcated and centered on blood vessel with deposition of immunoglobulin and complement. Pattern 2 - active plaque sharply demarcated and centered on blood vessel without deposition of immunoglobulin or complement. 2. Devics - - AKA neuromyelitis optica - combination of bilateral optic neuropathy and transvers myelitis. Optic neuritis can occur concurrently, or one may follow the other. Diagnostic criteria for NMO - optic neuritis, myelitis, and one of the following: MRI evidence of a contiguous spinal cord lesion 3 or more segments in length, or seropositivity for NMO IgG. Although original diagnostic criteria for NMO didn't permit CNS involvement (beyond optic nerves and spinal cord), revised criteria allow for other brain lesion in patients who otherwise meet criteria for NMO. 3. ADEM - T 4. Typical of MS - F - typical is plaxues perpendicular to ventricles / callososeptal interface.

Answer 47

Answer: Very radiosensitive. Excellent prognosis even if extends retro-orbitally (Least likely) From Robbins/Radiopaedia: Retinoblastoma - Most common primary intraocular malignancy of children. - 40% of cases have a germline mutation. - mutation is inherited in an autosomal dominant fashion, with 90% penetrance. I.E the child of a retinoblastoma survivor who has a germline mutation has a 50% change of inheriting a mutation, and if they do so a 90% change of developing retinoblastoma. They thus have an overall probability of 45% of having a retinoblastoma. - prognosis is adversely affected by extra ocular extension and invasion along the optic nerve and by choroidal invasion. - Risk of tumor recurrence following ext XRT 7%, occurring within 40months. Also risk of secondary cancers with XRT. - Trilateral/quadrilateral retinoblastoma: bilateral ocular retinoblastoma + pineal and suprasellar tumors.

Answer 48

ANSWER:1. Intracortical T - well-demarcated "bubbly" cortical mass 3. Sep03.64 DNET: (TW & GC) 1. Intracortical T - well-demarcated "bubbly" cortical mass 2. Cystic F - pseudocystic imaging appearance due to hypodensity. Histology may show "floating neurons" + mucinous degeneration. 3. Angiogenesis F - pathological hallmark is the "specific glioneuronal element": columns of heterogeneous cells oriented perpendicular to cortex. Also glial nodules and cortical dysplasia. 4. WHO grade II F - grade I 5. Frontal lobe F - temporal lobe 62%, frontal lobe 31%[Adelaide notes, Dahnert, RG 2001]

Answer 49

2. Is associated with Down’s syndrome – F – Assoc with abnormal karyotype (T13, 15, 18 – not typically assoc with T21, however there are some case reports). Multiple other assoc: Dandy-Walker cyst, interhemispheric arachnoid cyst, hydrocephalus, intracerebral lipoma of CC, AC II malformation, porencephaly, Holoprosencephaly, polymicrogyria. 3. The following statements regarding agenesis of the corpus callosum, false?: (TW) 1. Ventriculomegaly predominantly affects the occipital horns – T – occipital horns often dilated (colpocephaly). Pointed frontal horns. Can get dilation of the posterior temporal horns in the absence of splenium. 2. Is associated with Down’s syndrome – F – Assoc with abnormal karyotype (T13, 15, 18 – not typically assoc with T21, however there are some case reports). Multiple other assoc: Dandy-Walker cyst, interhemispheric arachnoid cyst, hydrocephalus, intracerebral lipoma of CC, AC II malformation, porencephaly, Holoprosencephaly, polymicrogyria. 3. The lateral ventricles are widely placed – T- “bat-wing” appearance of lateral ventricles (= wide separation of lateral ventricles with straight parallel parasagittal orientation with absent callosal body) 4. There is an association with heterotopic gray matter – T – polymicrogyria, gray-matter heterotopia 5. It is associated with colpocephaly - T

Answer 50

ANSWER: Majority of newborns have systemic signs of disease, of which half have CNS involvement. FROM ROBBINS - Occurs in foetuses and immunosuppressed individuals. - the outcome of infection in utero is periventricular necrosis that produces severe brain destruction followed later by microcephaly and periventricular calcification. - In immunosuppressed: commonly causes subacute encephalitis. - Infection localised in paraventricular subependymal regions where it results in a severe hemorrhagic necrotising ventriculoencephalitis and a choroid plexitis. - any cell in the CNS may be infected. - prominent enlarged cells with intranuclear inclusions (Cowdry B), histologic "owl's eyes". FROM STATDX (with regards to newborns/congenital CMV) - Most infected newborns appear normal - 10% have systemic signs of disease - of the newborns with systemic signs of disease, 55% have CNS involvement.

Answer 51

4. Anaplastic astrocytoma F - central white matter of cerebrum, typically frontal & temporal lobes. 30. Which is not associated with brain cortical involvement: (GC) 1. DNET T - nodular cortical mass, background of cortical dysplasia; WHO grade I. 2. Oligodendroglioma T - most commonly involve cortex & subcortical WM, may have Ca2+, frontal >temp; WHO grade I. 3. Pleomorphic xanthoastrocytoma T - superficial supratentorial tumour that involves the leptomeninges, most commonly in the temporal lobe. WHO grade II, relatively high recurrence rate, malignant transformation in 20%. 4. Anaplastic astrocytoma F - central white matter of cerebrum, typically frontal & temporal lobes. 5. Ganglioglioma T - most common cause of chronic temporal lobe epilepsy; WHO grade I. Superficial gliomas: - glial neoplasms that are peripherally located and involve the cortical grey matter - commonly a seizure locus - amenable to surgical resection, with generally favorable prognosis - include: ganglioglioma, gangliocytoma, Lhermitte-Duclos (dysplastic cerebellar gangliocytoma), DNET, desmosplastic infantile ganglioglioma, pleomorphic XA. [RG 2001]

Answer 52

4. Neurofibrillary tangles in occipital region - NFT's are commonly found in the entorhinal cortex, as well as in pyramidal cells of hippocampus, amygdala, basal forebrain, raphe nuclei. Perhaps in advanced dementia there may be occipital cortex involvement (?). Posterior cortical atrophy (Benson's syndrome) and Balint's syndrome may be regarded as variants of AD, whereby deposition of neuritic plaques and NFT's are specifically revealed in the posterior cerebral areas (occipital cortex, visual cortex). [Acta Neuropathologica 1993]

Answer 53

2. CJD patients live for <12 months, vCJD live for a few years.

Answer 54

Rosenthal fibres Rosenthal fibres often present = eosinophilic bodies within astrocyte processes. • up to 100% 5YS • Rosenthal fibers present in o Pilocytic astrocytoma o glioma o pineal tumor o Alexander’s disease o long-standing gliosis, MS plaques **SCS: dahnert Solid 33% Ass/w NF 1 (15-21%, optic pathway location) Prognosis: Excellent. 5 and 10 year survical >95%

Answer 55

1. Intracortical

Answer 56

ANSWER:b. See INCREASED ADC value 33. In drug resistant Parkinsons and autonomic neuropathy an MRI would look for all the following except? (TW) - Multiple system atropy a. Striatonigral degeneration - T - predominant degeneration of substantia nigra and striatum, with putamen > caudate nucleus b. Decreased putaminal ADC values - F - DWI appears to differentiate Parkinsons Disease from progressive supranuclear palsy and the Parkinsons variant of multiple system atropy. c. Cerebellar atrophy - T - hemispheres > vermis d. Cruciform pontine hyperintensity - T - hot cross bun sign (but not pathognomonic of MSA) MSA - striatonigral degeneration: clinically similar to idiopathic PD in presentation but is relatively resistant to L-dopa treatment (due to pattern of neuronal degeneration - ie both dopaminergic projections and its target neurons are absent, therefore L-dopa cannot bulster neurotransmission as occurs in parkinsons disease). Also have gross atrophy of caudat nucleus and putamen. Some patients also show evidence of pontocerebellar degeneration.DWI - appears to differentiate PD from progressive supranuclear palsy and Parkinson variant of MSA. in MSA-Pv get increased putaminal ADC values. In PSP have increased ADC in putamen, GP, and caudate nucleus. Path notes. Osborn. Brain 2006 129(10).

Answer 57

*Ry - depends on how you interpret it - based on the data someone has gathered below, could say 3 least common if considering 'adjacent to nose' as being olfactory groove. 4. adjacent to nose • Most common o Hemispheric convexity (20%) o Parasagittal (25%) → may occlude SSS • Very common o Sphenoid ridge, wing (15 – 20%) → may involve optic canal, wing meningiomas often en plaque Yock p26 Case 42 o Olfactory groove (5 – 10%) • Common o Parasellar (5 – 10%) CR p79 Case 63 o Cavernous sinus CR p11 Case 7 • 66% partially or totally encase carotid artery • 33% narrow the artery • Less common o CPA, along clivus (posterior fossa – 10%) Yock p38 Case 63 TA p3 Case 1 o Tentorium cerebelli Yock p36 Case 59 o Foramen magnum Yock p38 Case 64 • Rare o Optic nerve sheath (<2%) CR p155 Case 119 o Extracranial (nose, sinuses, skull (intraosseous)) o Intraventricular • usually trigone of (L) lateral ventricle Yock p40 Cases67-70 • most common trigonal mass in adults o Spinal canal (M : F = 1:10 ) • mostly thoracic region o Sylvian fissure Yock p31 Case 51 • Paediatric age group

Answer 58

ANSWER: d. Decreased N-myc amplification T - less copies of gene is better 34. Neuroblastoma, which is not associated with a worse prognosis: (GC) a. Age > 1 year F - age < 1yr has a better prognosis b. Stage 4B F - stage 4S has a near 100% survival c. Abdominal primary F - thoracic primary has a better prognosis d. Decreased N-myc amplification T - less copies of gene is better e. Metastases to bone only F - mets to liver and skin is associated with better prognosis

Answer 59

*AJL 2. Fat soluble medium cannot pass if normal BBB - false. (just remember that contrast cannot pass the BBB and it is water soluble therefore water soluble medium cannot pass. The other one (fat) can pass) 35. BBB, which is incorrect: (GC) ANSWER: 2 1. H2O soluble medium cannot pass if normal BBB T - solutes with high affinity for plasma water, low affinity for plasma proteins, and high extremely low partition coefficients do not penetrate normal BBB (eg. contrast media). 2. Fat soluble medium cannot pass if normal BBB 3. Capillaries are continuous 4. Continuous capillaries have no fenestrations 5. Tight junctions are important

Answer 60

1. Necrosis T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation

Answer 61

ANSWER: 1.1. Hippocampus 35. Least likely site for hypertensive bleed in the brain is: (GC) ANSWER: 1.1. Hippocampus 2. Cerebellum F - 10%; behave like SOL's - herniation & obstructive hydrocephalus. 3. Basal ganglia F - with thalamus account for 65% of hypertensive bleeds 4. Thalamus F - see above 5. Brainstem F - 10% [Adelaide path notes]

Answer 62

2. Glioblastoma multiforme T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation; with thickened vascular walls due to endothelial cell hyperplasia and hypertrophy; usually hypercellular with mitotic figures (some atypical), multinucleated tumor cells, bizarre nuclei, karyorrhectic cells; may have perinecrotic pseudopalisading of tumor cells around necrotic tumor. 35. Necrosis is a characteristic feature of: (GC) 1. Pilocytic astrocytoma F - WHO grade I; bipolar cells with elongated hairlike processes; Rosenthal fibers; may have microscopically infiltrative margin; mural nodule may be highly vascular; often calcifications. Rarely malignant degeneration with hypercellularity, mitotic figures and necrosis. 2. Glioblastoma multiforme T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation; with thickened vascular walls due to endothelial cell hyperplasia and hypertrophy; usually hypercellular with mitotic figures (some atypical), multinucleated tumor cells, bizarre nuclei, karyorrhectic cells; may have perinecrotic pseudopalisading of tumor cells around necrotic tumor. 3. Acoustic schwannoma F - interlacing fascicles; biphasic with Antoni A (cellular) and B (myxoid) patterns and Verocay bodies (palisading nuclei); no/rare mitotic figures. Cystic change may be due to intratumoral hemorrhage. 4. Craniopharyngioma F - Adamantinomatous (kids): relatively poorly circumscribed, nests and trabeculae of epithelium in fibrocollagenous stroma; nuclear palisading; often "wet" keratin, may undergo cystic degeneration, calcification, xanthogranulomatous reaction; cyst fluid contains cholesterol crystals, cholesterol clefts, reactive giant cells; variable necrosis, inflammation and Rosenthal fibers; no keratohyaline granules Papillary (adults): well-circumscribed, cores of fibrovascular stroma lined by well-diffd squamous epithelium that may form pseudopapillae. 5. Ependymoma F - solid or papillary, small blue fibrillar to epithelioid cells with granular chromatin; form perivascular rosettes and less commonly ependymal rosettes. [Path outlines]

Answer 63

*AJL - (from radiopaedia) The tumour appears as a large, demarcated, solid mass featuring patchy or no contrast enhancement, with surrounding oedema, often with significant mass effect. A minority of the reported cases have shown cystic components and microcalcifications. Therefore I think the answer is actually 4 - vasogenic oedema, based on current classification **LJS - not sure. ETMR replaces several tumours in new WHO classification, not just PNET. Let's hope the question is gone. But if not I would probably answer as per the old PNET classification and say angiogenesis. Previuos ANSWER:2. Angiogenesis T - 35. PNET, which is the most typical appearance: (GC) 1. Cortical F - deep cerebral white matter, most commonly frontal lobe. 2. Angiogenesis T - WHO grade IV. Supratentorial PNETs had highly branched capillaries with extensive endothelial cell hyperplasia. Glomeruloid arrays of microvessels extended from the capillaries. Small fragments of endothelial tubes were scattered throughout the tumor. [Different vascular patterns of medulloblastoma & supratentorial PNETs. Internat J of Dev Neuroscience 1999] 3. Cystic F - large (hemispheric) heterogeneous mass with tendency for necrosis (65%), cyst formation, calcification (71%), haemorrhage (10%). 4. Vasogenic oedema F - thin rim of oedema 5. Astrocytoma F

Answer 64

1. majority occur at branch points • About 90% of berry aneurysms occur in the anterior circulation and are found near major arterial branch points. • Multiple aneurysms exist in 20-30% of autopsy series.

Answer 65

ASNWER: 1 .1. DNET T - nodular intracortical lesion +/- cortical dysplasia, temporal lobe (62%). 35. Solid mass involving the cortex of a temporal lobe is demonstrated on MRI. Most likely diagnosis is: (GC) ASNWER: 1 .1. DNET T - nodular intracortical lesion +/- cortical dysplasia, temporal lobe (62%). 2. Pilocytic astrocytoma F - usually cystic with mural nodule, may be solid or diffusely infiltrative (eg. optic n.). Usually midline - cerebellum, 3rd V, thalamus-hypothalumus. 3. Anaplastic astrocytoma F - found in hemispheres, usually frontal & temporal lobes. 4. Mesial temporal sclerosis F - 5. Pleomorphic xanthoastrocytoma F - most common in temporal lobe, superficial cortical location is typical, involves (attached to) leptomeninges. But is usually cystic (48%) with mural nodule; occasionally more diffuse with gyral infiltration. [Adelaide path notes, Dahnert]

Answer 66

ANSWER:d. Dandy Walker F - assocd with dysgenesis of the CC in 20-25% (cf. primary involvemt) 40. Which is least likely to involve the corpus callosum: (GC) a. GBM T - most commonly spread via direct extension along WM tracts, including the CC - classic butterfly pattern. b. Marchifava Bignami T - primarily affects the CC - acute form affects the genu & splenium, chronic form affects the body. c. DAI T - classic triad of GW junction, dorsolateral brainstem, and CC (most commonly eccentrically and in the splenium). d. Dandy Walker F - assocd with dysgenesis of the CC in 20-25% (cf. primary involvemt) e. Lymphoma T - differ from GBM as usually less peritumoral oedema, less often necrotic, highly radiosensitive, frequently respond dramatically to steroids. [AJR 2002]

Answer 67

ANSWER:a. Oligodendroglioma T - characteristically involves cortex and subcortical WM. 35. Which is most likely to involve cortex: (GC) a. Oligodendroglioma T - characteristically involves cortex and subcortical WM. b. Low grade glioma F c. Meningioma F - extra axial. Rarely atypical meningiomas may show sarcomatous transformation with spread over entire hemisphere and invasion of cerebral parenchyma (leptomeningeal supply). d. Ependymoma F - supratentorial tumours frequently grow into brain parenchyma extending to the cortical surface, esp in frontal and parietal lobes. May see scalloping of inner table or invasion of overlying meninges/bone. [Dahnert] Changed 2. from low grade anaplastic astrocytoma

Answer 68

2. Lewy bodies F - Parkinson's disease

Answer 69

1. hippocampus

Answer 70

c. Lymphocytic hypophysitis

Answer 71

Answer: GBM. a. Pilocytic astrocytoma F - WHO grade I; bipolar cells with elongated hairlike processes; Rosenthal fibers; may have microscopically infiltrative margin; mural nodule may be highly vascular; often calcifications. Rarely malignant degeneration with hypercellularity, mitotic figures and necrosis. b. Glioblastoma multiforme T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation; with thickened vascular walls due to endothelial cell hyperplasia and hypertrophy; usually hypercellular with mitotic figures (some atypical), multinucleated tumor cells, bizarre nuclei, karyorrhectic cells; may have perinecrotic pseudopalisading of tumor cells around necrotic tumor. c. Acoustic schwannoma F - interlacing fascicles; biphasic with Antoni A (cellular) and B (myxoid) patterns and Verocay bodies (palisading nuclei); no/rare mitotic figures. Cystic change may be due to intratumoral hemorrhage. d. Craniopharyngioma F - Adamantinomatous (kids): relatively poorly circumscribed, nests and trabeculae of epithelium in fibrocollagenous stroma; nuclear palisading; often "wet" keratin, may undergo cystic degeneration, calcification, xanthogranulomatous reaction; cyst fluid contains cholesterol crystals, cholesterol clefts, reactive giant cells; variable necrosis, inflammation and Rosenthal fibers; no keratohyaline granules Papillary (adults): well-circumscribed, cores of fibrovascular stroma lined by well-diffd squamous epithelium that may form pseudopapillae. e. Ependymoma F - solid or papillary, small blue fibrillar to epithelioid cells with granular chromatin; form perivascular rosettes and less commonly ependymal rosettes. [Path outlines]

Answer 72

ANSWER: DNET FROM ROBBINS/RADIOPAEDIA DNET - rare low-grade tumor of childhood (WHO I). - located in superficial temporal lobe (65% of cases). - Gross macro: expanded cortex with mixed solid/cytic, mucoid mass. PILOCYSTIC ASTROCYTOMA - low grade tumor of childhood (WHO I) - usually located in posterior fossa. - separated from other astrocytomas by rarity of TP53 mutation. - gross macro: cystic with mural nodule - micro: Rosenthal fibers. ANAPLASTIC ASTROCYTOMA - WHO III tumor. most common in 40-50 yo adults. - gross macro: infiltrating mass with poorly delineated margins. - hemispheric white matter most common, frontal and temporal lobes. PLEOMORPHIC XANTHOASTROCYTOMA - Children. Rare <1% of astrocytomas. - 98% supratentorial. Temporal lobe most common (40-50%). - consists of neoplastic occasionally bizarre astrocytes, sometimes filled with lipids. (WHO II/III). - macro: cortical mass. usually cystic (48%) with mural nodule. DDX FOR TEMPORAL LOBE TUMOURS - Pleomorphic xanthoastrocytoma - ganglioglioma - Pilocytic astroctyoma - DNET - Multinodular and vacuolating neuronal tumors

Answer 73

ANSWER:1. Hippocampus 39. Least likely site for hypertensive bleed in the brain is: (GC) 1. Hippocampus 2. Cerebellum F - 10%; behave like SOL's - herniation & obstructive hydrocephalus. 3. Basal ganglia F - with thalamus account for 65% of hypertensive bleeds 4. Thalamus F - see above 5. Brainstem F - 10%

Answer 74

3. sudden loss after minor trauma is typical for vestibular aqueduct synd - T ) Sensorineural hearing loss, which is true (TW) 1. destruction of ossicular chain from otitis media - F - conductive 2. cochlear SNHL is more common than retrocochlear SNHL - F - other way around. retrocochlear SNHL (abnormalities of neurons of the spiral ganglion) more common than cochlear SNHL (damage to cochlea / organ or Corti). Dahnert 6th. 3. sudden loss after minor trauma is typical for vestibular aqueduct synd - T

Answer 75

4. 86.APRIL02 Which of the following statements concerning hypertensive haemorrhage IS LEAST correct? Answer: 4. Less than 1% occur in the posterior fossa 1. They are related to the lenticulo-striate arteries (lateral lenticulostriate arteries) 2. They are most common in the putamen (Putamen / external capsule 60 – 65 %) 3. They occur secondary to focal cerebral infarction (lacunar infarcts) 4. Less than 1% occur in the posterior fossa 5. They are not due to cerebral emboli (NOT due to emboli) • Major sites o Predilection for areas supplied by penetrating branches of MCA & basilar artery: • 2/3rd's in basal ganglia • Putamen / external capsule 60 – 65 % • Thalamus 15 – 25 % • Pons 5 – 10% • Cerebellum 2 – 5 % • These behave like space occuping lesions leading to herniation and obstructive hydrocephalus • Subcortical lobar white matter 1 – 2 %

Answer 76

1. Fat fluid level and satellite lesion suggests demyelination

Answer 77

Answer: none of the above. ?Incorrect recall. All have small round blue cells. Pleomorphic Rhabdomyosarcoma does not contain small round blue cells, but not found in children. FROM ROBBINS Neuroblastoma - Undifferentiated neuroblastic tumor of the sympathetic ganglia and adrenal medulla derived from primordial neural crest cells. - histology: composed of small primitive-appearing cells with dark nuclei, scant cytoplasm, and poorly defined cell borders growing in solid sheets. Homer-Wright pseudo rosettes can also be found Ewing's Sarcoma - a malignant bone tumor characterised by primitive round cells without obvious differentiation. - Comes under the Ewing sarcoma family tumors (which include PNET, Ewing sarcoma of bone, extra osseous Ewing, Askin tumor, neuroepithelioma - Histology: composed of sheets of uniform small, round cells. Also present of Homer-Wrist rosettes. Rhabdomyosarcoma - malignant mesenchymal tumor with skeletal muscle differentiation. - 3 subtypes: Alveolar (20%), embryonal (60%), pleomorphic (20%). - Alveolar and embyronal: most common soft tissue sarcoma of childhood and adolescence (<20 years old). Arises in sinuses, H&N, GU tract. - Pleomorphic: seen in adults. - Histo of embryonal and alveolar types - cells have scant cytoplasm and a centrally placed round nucleus that occupies the majority of the cell. Wilms Tumor - Malignant tumor of primitive metanephric blastema - Most common primary renal tumor of childhood (USA) - 4th most common pediatric malignancy (USA) - peak incidence 2-5 years old. - 5-10% involve both kidneys, either synchronously or metchronously. - 10% associated with syndromes (3 main groups) - group 1: WAGR syndrome. Group 2: Denys-Drash syndrome. Groups 3: Beckwith-Wiedeman syndrome. - Histology: classic triphasic combination of Blastema (sheets of small blue cells), stromal, and epithelial cell types. Retinoblastoma - cell of origin is neuronal progenitor. 40% cases occur in individuals with RB gremline mutation. - most common primary intraocular malignancy in children - histology: sheets, trabeculae and nests of small blue cells with scant cytoplasm - Well-differentiatied tumors have Flexure-Wintersteiner rosettes. FROM RADIOPAEDIA DDX for small round blue cell tumors - EWSFT (Ewing, askin, PNET, EES) - Neuroblastoma - Wilms tumor - Hepatoblasoma - Embryonal/alveolar Rhabdomyosarcoma - Medullobalstoma - Pineoblastoma - Retinoblastoma - ETMR (previously CNS PNET) - Desmoplastic small round cell tumor - small cell mesothelioma

Answer 78

ANSWER:c. Wernicke's encephalopathy T - usually abrupt onset of nystagmus, gaze palsies, ataxia and mental confusion. Due to thamine (vit B1) deficiency. Korsakoff's syndrome is closely linked to Wernicke's and my be viewed as different stages of the same process - symptoms are of retentive memory impairment and confabulation 4. Chronic alcoholic; speech preserved, no facial droop, ataxia. Most likely diagnosis: (GC) A . a. Alcoholic cerebellar degeneration F - staccato speech, wide-based gait and truncal ataxia b. Marchiafava Bignami F - variable presentation, some with sudden onset stupor/coma or seizures, some with dementia and/or gait problems. Psychiatric disturbances, incontinence, hemiparesis, aphasia, and apraxia have been described. [eMedicine] c. Wernicke's encephalopathy T - usually abrupt onset of nystagmus, gaze palsies, ataxia and mental confusion. Due to thamine (vit B1) deficiency. Korsakoff's syndrome is closely linked to Wernicke's and my be viewed as different stages of the same process - symptoms are of retentive memory impairment and confabulation. d. Superior cerebellar artery infarct F - usually dysarthric as well as ataxic, +/- vestibular signs (N&V, dizziness). [Stroke 1996] e. Central pontine myelinolysis F - pseudobulbar palsy (head & neck weakness, dysphagia, and dysarthria), spastic quadriplegia, delirium is extremely common. May have horizontal gaze paralysis, or "locked-in syndrome" (paralysis of lower cranial nerves and limb musculature. Vertical eye movements, blinking, breathing, and alertness may remain intact in these patients). [eMedicine] Added options a, b, d, e.

Answer 79

. Lewy bodies F - eosinophilic intracytoplasmic inclusions found in some neurones in Parkinson's disease. 4. Which is not a feature of Alzheimer’s: (GC) 1. Hirano bodies T - elongated glassy eosinophilic bodies of paracrystallline arrays of beaded filaments predominantly of actin, found mostly in hippocampal pyramidal cells in AD. 2. Lewy bodies F - eosinophilic intracytoplasmic inclusions found in some neurones in Parkinson's disease. 3. Senile plaques T - aka neuritic plaques; focal spherical collections of dilated tortuous silver-staining neuritic processes (dystrophic neurites) surrounding a central amyloid core. 4. Neurofibrillary tangles T - bundles of filaments in cytoplasm of neurons that displace or encircle the nucleus, 'flame-shaped', seen well with silver staining (especially in cortical neurones). Characteristic but not specific to AD; also seen in PSNP, postencephalitic PD, ALS-parkinsonian-dementia complex of guam (!) 5. Amyloid T - almost an invariable accompaniment of AD. Beta-amyloid and its precursor protein (APP) are implicated in the aetiopathogenesis. Nash:- NFT- amyloid- senile plaque- hiring body

Answer 80

1. Kernohan’s notch in the parietal lobe - F - displacement of brainstem against the contralateral tentorial edge with injury to the brain stem, not parietal lobe. 4. Which is not associated with raised intracranial pressure? (TW) 1. Kernohan’s notch in the parietal lobe - F - displacement of brainstem against the contralateral tentorial edge with injury to the brain stem, not parietal lobe. 2. Duret haemorrhage of the cerebral peduncle - T - brain stem hemorrhage involving midbrain and pons / haemorrhage in lateral brain stem due to massive temporal lobe herniation. 3. Infarct contralateral medial occipital lobe - T - generally there is ispilateral compression of PCA 1st, followed by contralateral side. 4. Early findings of enlarged ipsilateral ambient cistern - T - ipsilateral CPA cisterns also enlarge (Osborn).

Answer 81

1. Necrosis T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation

Answer 82

ANSWER: 2. Fat soluble medium cannot pass if normal BBB F - lipophilic solutes do not have a significant affinity for plasma proteins and are able to pass into the luminal plasma membrane lipid with ease, and hence into the brain. 1. H2O soluble medium cannot pass if normal BBB T - solutes with high affinity for plasma water, low affinity for plasma proteins, and high extremely low partition coefficients do not penetrate normal BBB (eg. contrast media). 2. Fat soluble medium cannot pass if normal BBB F - lipophilic solutes do not have a significant affinity for plasma proteins and are able to pass into the luminal plasma membrane lipid with ease, and hence into the brain. 3. Capillaries are continuous T - this is the basis of the BBB. Other types are fenestrated (circumventricular organs), and sinusoidal (liver, spleen, bone marrow). 4. Continuous capillaries have no fenestrations T - wall is composed of a single layer of endothelial cells connected by tight junctions, surrounded by a continuous basement membrane. It is the continuity of the interendothelial tight junctions, lack of pinocytosis and absence of fenestrations that contribute to the restricted permeability of the BBB. 5. Tight junctions are important T - see above.

Answer 83

ANSWER: a. Oligodendroglioma T - characteristically involves cortex and subcortical WM. 41. Cortically based lesion, which is most likely: (GC) a. Oligodendroglioma T - characteristically involves cortex and subcortical WM. b. Low grade glioma F c. Meningioma F - extra axial. Rarely atypical meningiomas may show sarcomatous transformation with spread over entire hemisphere and invasion of cerebral parenchyma (leptomeningeal supply). d. Ependymoma F - supratentorial tumours frequently grow into brain parenchyma extending to the cortical surface, esp in frontal and parietal lobes. May see scalloping of inner table or invasion of overlying meninges/bone. [Dahnert]

Answer 84

ANSWER: d. Dandy Walker F - assocd with dysgenesis of the CC in 20-25% (cf. primary involvemt) 42. Which is least likely to involve the corpus callosum: (GC) a. GBM T - most commonly spread via direct extension along WM tracts, including the CC - classic butterfly pattern. b. Marchifava Bignami T - primarily affects the CC - acute form affects the genu & splenium, chronic form affects the body. c. DAI T - classic triad of GW junction, dorsolateral brainstem, and CC (most commonly eccentrically and in the splenium). d. Dandy Walker F - assocd with dysgenesis of the CC in 20-25% (cf. primary involvemt) e. Lymphoma T - differ from GBM as usually less peritumoral oedema, less often necrotic, highly radiosensitive, frequently respond dramatically to steroids. [AJR 2002] Completed using stems from Aug 2006, previously only had DWS [Eric] Associated anomalies include: o Chiari II malformation o Dandy-Walker complex o Neuronal migration disorders o Cephalocoeles o Schizencephaly o Interhemispheric lipoma – tubulonodular type o Azygous anterior cerebral arteries

Answer 85

1. Detectable at angiography F - most are angiographically occult due to slow flow **LJS - also no intervening normal brain (stat dx)

Answer 86

ANSWER:1. Necrosis T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation 43. GBM what is the most important feature in Dx: (GC) 1. Necrosis T - high grade astrocytoma (anaplastic, fibrillar astrocytes) with either coagulation necrosis or microvascular proliferation 2. Angiogenesis ? - microvascular proliferation is also a Dx feature 3. Cystic change F - non specific feature 4. Mitosis F - abnormal mitoses are also present in grade III (anaplastic) astrocytoma 5. Vasogenic oedema F - non specific feature WHO grading & Histological criteria: I Pilocytic astrocytoma - II Diffuse astrocytoma - 1 criterion, usually nuclear atypia III Anaplastic astrocytoma - 2 criteria, usually nuclear atypia and mitoses IV Glioblastoma - 3 criteria, usu nuclear atypia, mitoses, microvasc proliferation +/or necrosis

Answer 87

1. Detectable at angiography F - most are angiographically occult due to slow flow. 44. Cavernous Angioma – which is is not typical: (GC) 1. Detectable at angiography F - most are angiographically occult due to slow flow. 2. Bleeding tendency T - nearly all show evidence of recent and remote hemorrhage, as suggested by the presence of hemosiderin-laden macrophages, cholesterol crystals, and hemosiderin-stained parenchymal tissues. 3. No intervening normal brain - this is the only histopathologic characteristic that distinguishes these lesions from capillary telangiectasias. 4. Pseudocapsule + surrounding hemosiderin laden macrophages T - clots and blood products of various stages of evolution within the lesion, as well as calcification and gliosis surround the cavernoma, creating the appearance of a pseudocapsule. 5. Associated venous angioma T - persistent elevations in venous pressures, as may be seen locally within a venous malformation, may promote a pathologic reactive angiogenesis or angiogenic proliferation, resulting in abnormal blood vessel growth and coalescence. [eMedicine]

Answer 88

Answer: Probably chickenpox (see below) FROM ROBBINS In general, fetal and perinatal infections are acquired through one of 2 primary routes - transcervically (ascending), or transplacentally (hematologic). Transcervical (ascending): most bacterial and a few viral acquired this way. Transplacental (hematologic): most parasitic and viral infections acquired this way. The TORCH group of infections are grouped together because they may evoke similar clinical and pathological manifestations i.e. fever, encephalitis, chorioretinitis, hepatosplenomegaly, pneumonitis, myocarditis, haemolytic anaemia, and vesicular skin lesions. TORCH - Toxoplasmosis - Other (syphillis, varicella zoster, parvovirus) - Rubella - Cytoomegalovirus - Herpes simplex virus FROM RADIOPEDIA The mechanism of congenital malformations caused by varicella-zoster virus seems to be not due to fetal varicella infection but to the development of maternal herpes zoster in utero and to an encephalitis associated with herpes zoster

Answer 89

ANSWER:1. a. Hurthle cells -T - mononuclear inflammatory infiltrate containing small lymphocytes, plasma cells, and well-developed germinal centers. The thyroid follicles are small and are lined in many areas by epithelial cells with abundant eosinophilic, granular cytoplasm, termed Hurthle cells.1. 46. Hashimoto’s – FNA findings (TW) a. Hurthle cells -T - mononuclear inflammatory infiltrate containing small lymphocytes, plasma cells, and well-developed germinal centers. The thyroid follicles are small and are lined in many areas by epithelial cells with abundant eosinophilic, granular cytoplasm, termed Hurthle cells. b. Fibrosing nodules - F - Reidel's thyroiditis. c. Psammoma bodies - F - in papillary thyroid carcinoma. Concentrically calcified structures.= o ns = Hurthle cells seen in: o Hashimotos o Follicular adenoma

Answer 90

ANSWER:2. Lewy Bodies F - eosinophilic intracytoplasmic inclusions found in some neurones in Parkinson's disease 47. Which is not a feature of Alzheimer’s: (GC). 1. Hirano bodies T - elongated glassy eosinophilic bodies of paracrystallline arrays of beaded filaments predominantly of actin, found mostly in hippocampal pyramidal cells in AD. 2. Lewy Bodies F - eosinophilic intracytoplasmic inclusions found in some neurones in Parkinson's disease. 3. Senile Plaques T - aka neuritic plaques; focal spherical collections of dilated tortuous silver-staining neuritic processes (dystrophic neurites) surrounding a central amyloid core. 4. Neurofibrillary tangles T - bundles of filaments in cytoplasm of neurons that displace or encircle the nucleus, 'flame-shaped', seen well with silver staining (especially in cortical neurones). Characteristic but not specific to AD; also seen in PSNP, postencephalitic PD, ALS-parkinsonian-dementia complex of guam (!) 5. Granulovacuolar degeneration T - small clear intraneuronal cytoplasmic vacuoles, each containing a granule. 6. Amyloid T - almost an invariable accompaniment of AD. Beta-amyloid and its precursor protein (APP) are implicated in the aetiopathogenesis.

Answer 91

Answer: ??Angiogenesis NOTE: OLD QUESTION. PNET is no longer in the current WHO classification of CNS Tumors. It now comes under the group "Embryonal Tumor with multilayered rosettes, C19MC altered (ETMR)" Not covered in Robbins. info from STATDX/RADIOPEADIA ETMRs - rare small round blue cell tumor of the CNS - aggressive brain tumor seen in children. WHO IV - encompasses PNET, ETANTR and ependymoblastomas. Appearances - Large irregular hemispheric mass (cortical/subcortical) - cystic components (65%) - Calcificationn (70%) - Hemorrhagic - minimal to no peritumoral oedema

Answer 92

4. spinal drop mets most likely posterior - T - normal flow of CSF from cisterna magna - highest concentration of potential tumor cells. 5) CME Medullo (TW) 1. resistant to XRT - F - highly radiosensitive. Rx with surgery and XRT. 2. ca2+ is most important differentiator from astro on CT - F - calcification is present in up to 20% in both MB and PCA. 3. desmoplastic in <3y - F - MB in adult patients often the desmoplastic histologic subtype (and are prone to recurrence). 4. spinal drop mets most likely posterior - T - normal flow of CSF from cisterna magna - highest concentration of potential tumor cells. 5. majority are lytic bone metastases - F - osseous lesions are usually sclerotic (65% sclerotic, 35% lytic). Bone is most common extraneural metastatic site.

Answer 93

Answer: 5. Degeneration of the central portion /body of the corpus callosum This is a feature of Marchiafavia Bignami disease (Big Robbins p1329 5. 87.APRIL02 A 38 year old man with disseminated tuberculosis is having an MRl/MRA of their brain. Which of the following would be the LEAST expected finding ) 1. Exudate in the basal cisterns (thick gelatinous exudate is found in the basal cisterns) 2. Hydrocephalus (Both CT and MR can also document communicating hydrocephalus, a common sequela of tuberculous meningitis) 3. 4cm intraparenchymal cerebral mass (tuberculoma) 4. Marked arterial irregularity (TB meningitis - Progressive obliterative arteritis) 5. Degeneration of the central portion /body of the corpus callosum This is a feature of Marchiafavia Bignami disease (Big Robbins p1329) • CNS TB may take a variety of forms, including tuberculous meningitis, abscess, focal cerebritis, and tuberculoma. • The most common radiographic findings associated with CNS TB include enhancement of the basal cisterns, granulomata, calcifications, hydrocephalus, meningeal enhancement, and infarction, most often of the basal ganglia. • Coexistent pulmonary TB is often present, seen in 25% to 83% of cases of CNS TB • Thick gelatinous exudate is found in the basal cisterns • Arteries that course through this exudate can become directly involved by the inflammatory infiltrate, indirectly by reactive endarteritis obliterans, or by both processes, with consequent spasm and intimal changes resulting in thrombosis and infarction. • Arteritis is present in approximately 28% to 41% of cases with basilar meningitis • The most common parenchymal form of CNS TB is tuberculous granuloma (tuberculoma). o Granulomata may be secondary to hematogenous spread of systemic disease or may evolve from extension of CSF infection into the adjacent parenchyma via cortical veins or small penetrating arteries o Pathologically, the granuloma is composed of a central zone of solid caseation necrosis, surrounded by a capsule of collagenous tissue, epithelioid cells, multinucleated giant cells, and mononuclear inflammatory cells • Tuberculomas may be found in the cerebrum, cerebellum, subarachnoid space, or subdural or epidural space. • Parenchymal disease most often involves the corticomedullary junction and periventricular regions, as expected for hematogenous dissemination. • Most tuberculomas are supratentorial

Answer 94

5. 4 year survival 50% F - current 5YS rate for patients with intracranial ependymomas is approximately 50%, when rates from children and adults are combined. Stratification based on age reveals 5YS rates of 76% in adults and only 14% in children. 5. Children with Ependymoma, which is false: (GC) 1. Prognosis poor – cannot remove completely T - Despite the survival advantage of gross total resection, lesions of the posterior fossa are in close proximity to cranial nerves with a significant risk of long-term neurologic dysfunction and disability. Hence, most tumors of the posterior fossa cannot be fully resected and are likely to recur without postoperative radiation. 2. Less common than medulloblastoma T - third most common paediatric brain tumour, after medulloblastoma & JPA. (Adelaide notes) 3. Does not metastasize as frequently as medulloblastoma T - subarachnoid dissemination via CSF rare, observed in <10% of patients at diagnosis when ependymoblastomas are excluded. The incidence is higher with infratentorial ependymomas than with supratentorial tumors (9% vs 1.6%). 4. Myxopapillary variant in filum terminale T - considered a biologically and morphologically distinct variant of ependymoma, occurring almost exclusively in the region of the cauda equina and behaving in a more benign fashion than grade II ependymoma. 5. 4 year survival 50% F - current 5YS rate for patients with intracranial ependymomas is approximately 50%, when rates from children and adults are combined. Stratification based on age reveals 5YS rates of 76% in adults and only 14% in children. In children, approximately 90% of ependymomas are intracranial - 70% infratentorial (usually arising from floor of 4th ventricle), 30% supratentorial. In adults and adolescents, 75% arise within the spinal canal. [eMedicine, Adelaide notes]

Answer 95

Answer: Normal disorganised tissue in normal position. Cellular elements are mature and identical to those found in remainder of organ, but do not reproduce the normal architecture of the surrounding tissue. Tumor-like malformation with tissues of particular part of body arranged haphazardly, usually with excess of one or more of its components. Examples of hamartomas: - hamartoma of lung, vascular hamartomas (hemangioma, lymphangiomas) - melanotic hamartoma (melanocytic naevus, spitz naevus, halo naevus, dysplastic naevus, blue naevus) - Skeletal hamartoms (exostoses) - generalised hamartomatous dysplasias (NF, TS).

Answer 96

1. Oligodendroglioma

Answer 97

Answer: adjacent to nose Meningioma locations - 90% supratentorial (Parasagittal/convexity 45%, sphenoid 15-20%, Olfactory groove 5-10%, parasellar 15-20%) - 8-10% Infratentorial (CPA most common site) - 2% Extradural (mostly intraossoues, calvarium) - <1% Extracranial (head/neck) - most common paranasal sinuses, less common: nasal cavity, parotid, skin. Types - Typical (WHO I): syncytial, fibroblastic, transitional, Psammomatous, Secretory, microcystic histological patterns - Atypical (WHO II): clear cell and chordoid histological patterns - Analplastics (WHO III): papillary and rhabdoid histological pattern Macro appearances/spread - Globular (most common) - En plaque - Multicentric

Answer 98

1. Endarteritis causes ischaemia. T - ischaemic infarcts of BG + internal capsule in 20-40%, due to vascular compression and/or occlusion of small perforating vessels in basal cisterns.

Answer 99

Answer: HSV1 is the commonest cause of herpes meningitis (FALSE ROBBINS HSV-1 Encephalitis - causes encephalitis, most commonly in children and young adults. - only 10% of affected individuals have a history of prior herpetic infection - Involves inferior and medial regions of the temporal lobes, and orbital gyri of frontal lobes. HSV-2 - In adults it causes meningitis - IN 50% of neonates born by NVD to women with active primary HSV genital infections, the neonates develop severe encephalitis - It can cause acute hemorrhagic and necrotizing encephalitis. 2. HSV1 is the commonest cause of herpes meningitis - F - HSV-2 is responsible for most cases of herpetic viral meningitis (Path notes). HSV-1 causes 95% of all herpetic encephalitis. 5. Which is false regarding HSV? (TW) 1. It is grossly necrotising and often haemorrhagic - T - hemorrhagic, necrotizing encephalitis of gray and white matter (primarily limbic system). Severe edema an dmassive tissue necrosis with hemorrhage typical. 2. HSV1 is the commonest cause of herpes meningitis - F - HSV-2 is responsible for most cases of herpetic viral meningitis (Path notes). HSV-1 causes 95% of all herpetic encephalitis. 3. 80 – 90% of children have had HSV 1 infection - F (less correct)- 30% of HSV-1 Abs found in university students. HSV-2 Abs up to 60% of lower socioeconomic groups, and 10-30% (HSV2) higher socioeconomic groups,...... and 3% in nuns were seropositive for HSV2. 4. HSV1 encephalitis most common in adults - T - Occurs at any age. Highest incidence in adolescents and yong adults. Approx 30% or patients are less than 20yo. IVM: memory aid - Saj has herpes. Saj = 3 letters. HSV 1 + 2 = 3.

Answer 100

c. Commonly cortical. F - most lesions occur in or near the midline, usually arising from the cerebellum, optic n/chiasm, hypothalamic-thalamic region. 53. Juvenile pilocystic astrocytoma, which is false? (GC) a. Even without surgery rarely fatal. T - WHO grade I, 10YS rate of up to 94%, 20YS 79%. b. Well circumscribed, easy to cut out. T - surgery generally regarded as curative when gross total resection attained. Resection of the mural nodule is the key surgical objective, since the surrounding cyst occurs as a simple reactive change in most cases (however, neoplastic changes in the cyst wall have been documented). Although most appear well-circumscribed macroscopically, they may infiltrate into the surrounding parenchyma for several mm. XRT is strictly avoided - significant morbidity in <5yo. and no clinical proof of preventing recurrence. c. Commonly cortical. F - most lesions occur in or near the midline, usually arising from the cerebellum, optic n/chiasm, hypothalamic-thalamic region. d. More benign behaviour when it occurs in patient with NF1 T - Only a small number of NF1 patients showed tumour progression 10yrs after diagnosis; and those with an optic pathway glioma had a longer interval btn primary dx and first recurrence cf. those without NF1. e. Abundant Rosenthal fibres T - classically biphasic - loose glial component, and compact piloid tissue (dense sheets of bipolar cells with fine fibrillary processes, abundant RF's). Rosenthal fibres are also seen in areas of longstanding brain gliosis.[RG 2004]

Answer 101

a. Endarteritis causes ischaemia. T - ischaemic infarcts of BG + internal capsule in 20-40%, due to vascular compression and/or occlusion of small perforating vessels in basal cisterns. 56. TB Meningitis, which is most correct: (GC) Bacilli seed to meninges, form small subpial/subependymal caseous foci. These Rich foci then rupture into SAS (if located deeper in brain will cause tuberculomas/asbcesses). a. Endarteritis causes ischaemia. T - ischaemic infarcts of BG + internal capsule in 20-40%, due to vascular compression and/or occlusion of small perforating vessels in basal cisterns. b. Small multiple miliary nodules in brain. T - but is an association, ie. miliary TB is usually associated with TB meningitis. Tuberculomas may be solitary (70%), multiple, or miliary. Seen in AIDS patients, infants + small children. c. Cannot be seen macroscopically. F - thick gelatinous exudate. d. Can be asymptomatic. F - usually the prodrome is non specific; symptoms include headache, vomiting, photophobia, fever, drowsiness, meningism and confusion, occurring over a period of 2-3wks. Fever and headache can be absent in 25%, malaise absent in up to 60%. Headache and mental state changes more common in elderly patients.[eMedicine, Dahnert, RG 2007]

Answer 102

c. Bilateral or unilateral enlarged lobes - T - gland may be unilaterally or bilaterally enlarged and firm, with an intact capsule. Both thyroid lobes are involved from the beginning in most patients. 59. Macroscopic features of de Quervains Thyroiditis (AKA subacute). (TW) a. Diffuse smooth symmetrical goiter - F - only mild-moderate enlargement (Dahnert, UptToDate), patchy with occasionally distinctly focal inlvolvement. On cut section - involved areas are firm and yellow-white and stand out from the more rubbery, normal brown thyroid substance. b. Multiple nodules - F - early scattered follicles may be entirely disrupted and replaced by PMN forming microabscesses. Later the characteristic changes: aggregates of cells around damaged follicles .c. Bilateral or unilateral enlarged lobes - T - gland may be unilaterally or bilaterally enlarged and firm, with an intact capsule. Both thyroid lobes are involved from the beginning in most patients.

Answer 103

2. enhancement lasts 3 months - T - Dahnert says Gd-DTPA enhancement of lesions on T1WI up to 8weeks following acute demyelination. Osborn says >90% of enhancing lesions disappear within 6 months. MS (TW) 1. juxta cortical favours MS vs age - F - calloseptal favors MS, plus infratentorial. 2. enhancement lasts 3 months - T - Dahnert says Gd-DTPA enhancement of lesions on T1WI up to 8weeks following acute demyelination. Osborn says >90% of enhancing lesions disappear within 6 months. 3. usually thoracic spinal lesion - F - predilection for cervical cord 4. perpendicular to long axis - F - parallell to long axis of spinal cord / perpendicular to the axis of CC, ventricles. *WJI - due to dual blood supply and slow metabolism u fibres are relatively protected form chronic small vessel ischaemic changes so I'd go with this if the wording was right.

Answer 104

Metachromic leukodystrophy T - progressive symmetrical areas of T2 hyperintensity, (confluent "butterfly-shaped" PVWM change), early sparing of the subcortical U-fibres. Late onset form (after puberty-4th decade) may manifest as pychiatric/behavioural OR CNS motor signs + peripheral neuropathy. Other forms: late infantile (6m-3yo, death in 5yrs), juvenile (4-12yo, slower progressn). . 15yo with psychosis, MRI showed diffuse WM abnormality. Which is most likely: (GC) 1. Metachromic leukodystrophy T - progressive symmetrical areas of T2 hyperintensity, (confluent "butterfly-shaped" PVWM change), early sparing of the subcortical U-fibres. Late onset form (after puberty-4th decade) may manifest as pychiatric/behavioural OR CNS motor signs + peripheral neuropathy. Other forms: late infantile (6m-3yo, death in 5yrs), juvenile (4-12yo, slower progressn). 2. ADEM F - multifocal punctate or large confluent areas of T2/FLAIR hyperintensity. 3. Huntington’s F - caudate nucleus atrophy. 4. HIV F - AIDS-dementia complex: cerebral atrophy, subtly increased SI on T2/FLAIR without mass effect (from leaky capillaries), may be focal/diffuse, symmetric/asymmetric, reversible/nonreversible. Symptoms are more of inattention, indifference and psychomotor slowing (progressing to frank dementia), i.e. not psychosis. (Dahnert, Pocket Rad paeds neuro)

Answer 105

answer:4. The pons is a rare site of hypertensive hemorrhage (<1%) (5-10%) 6. 89.APRIL02 Which of the following statements IS LEAST correct concerning hypertensive changes in the brain? 1. Severe hypertension may cause tentorial herniation due to diffuse cerebral edema 2. The putamen is the most common site of hypertension related hemorrhage (60-65%) 3. Hypertension is the principal cause of over 50% of primary cerebral hemorrhage 4. The pons is a rare site of hypertensive hemorrhage (<1%) (5-10%) 5. Histologically there is often a rim anoxic neural and glial change around an area old hemorrhage • Patients coming to postmortem examination may show an edematous brain weighing more than normal, with or without transtentorial or tonsillar herniation

Answer 106

1. Amyloid angiopathy - T - usually lobar. Older patients. Usually >70yo, normotensive, demented. 6. Atypical of basal ganglia lesion: (TW) 1. Amyloid angiopathy - T - usually lobar. Older patients. Usually >70yo, normotensive, demented. 2. Fahrs disease - F - Bilateral symmetric basal ganglia Ca+ on CT. Location: globus pallidus is most common site of Ca+ (lateral pallidum > medial pallidum). Other areas may include putamen, caudate nuclei, thalami, cerebellum (esp dentate nuclei), cerebral white matter, internal capsule. 3. CO poisoning - F - Globus pallidi is most common site of abnormality. Hypodensity in GP on UECT. T1 hypointensity (necrosis) and hyperintensity (hemorrhage) reported. T2 hyperintensity with hypintense rim (prob due to hemosiderin). 4. Hypertensive haemorrhage - F - striatocapsular (putamen/ext capsule) 60-65%, Thalamus 15-25%, pons / cerebellum 10%.

Answer 107

4. Depletion of oligodendrocytes is a feature of MS lesions SCS; robbins within a plaque there is relative preservation of the axons and depletion of oligodendrocytes. -In inactive plaques; inflammatory cells slowly disappear. Little to no myelin is found and there is a reduced number of oligodendrocyte nuclei - Axons in old plaques show severe demyelination and are also greatly diminished in number (hence volume loss on imaging).

Answer 108

ANSWER:4. Meningioma - F - extraaxial. Necrosis, cysts, haemorrhage may be seen in 8-23%. Can have assoc trapped CSF clefts 6. Cystic tumour in brain, least likely is (TW). 1. Hemangioblastoma - T - typically adult with intra-axial posteior fossa mass with cyst, enhancing mural nodule abutting pia. 2. JPA - T - common cystic lesion with mural nodule in children 3. PNET - T - PNET-MB - most common PF tumor in children (debatable vs JPA). Small intratumoral cysts / necrosis 40-50%. 4. Meningioma - F - extraaxial. Necrosis, cysts, haemorrhage may be seen in 8-23%. Can have assoc trapped CSF clefts. 5. Schwannoma - T - peripheral nerve sheath tumor which can be cystic and intraparenchymal. 1-2% intracerebral (superficial or periventricular location, cerebral hemisphere is most common site). Intracerebral schwannoma = cyst with nodule.Osborn.

Answer 109

3. Commonly cortical F - most lesions occur in or near the midline, usually arising from the cerebellum, optic n/chiasm, hypothalamic-thalamic region. **LJS - cerebellar hemisphere most common location (60%) then optic pathway. Does "cortical" mean cerebral cortex or include cerebellar cortex?

Answer 110

ANSWER: 1.1. paraganglioma, chemodectoma, and carotid body tumors can be used interchangeably - F - multiple names: glomus tumor, chemodectoma, endothelioma, perithelioma, sympathoblastoma, fibroangioma, sympathetic nevi. Paragangliomas are classified based on their location, innervation, and microscopic appearance. Would need to specify location for paraganglioma / chemodectoma to be able to use interchangeably with carotid body tumor. 6. Sep03.74 Paragangliomas (TW)ANSWER: 1.1. paraganglioma, chemodectoma, and carotid body tumors can be used interchangeably - F - multiple names: glomus tumor, chemodectoma, endothelioma, perithelioma, sympathoblastoma, fibroangioma, sympathetic nevi. Paragangliomas are classified based on their location, innervation, and microscopic appearance. Would need to specify location for paraganglioma / chemodectoma to be able to use interchangeably with carotid body tumor. 2. carotid body tumors often adherent to vessels resulting in incomplete excision and recurrence of 10% - T - Shamblin classification - Type I are localized and easily removed; type II adherent and partially surround carotid vessels; type III adherent and completely surround carotid vesels and extremely difficult to resect often requiring resection of ICA and vein graft interposition. Prevalence of local recurrence and local invasion - 40-50% of glomus jugulare tumors, 17% for vagal paragangliomas, and about 10% for carotid body tumors. 3. glomus jugulare and carotid body paragangliomas are the most common head and neck paragangliomas - T - conflicting reports regarding the prevalence of these 2 subtypes some saying one is more prevalent, some saying the other is. 4. paragangliomas have biphasic or biphenotypic pattern and composed of chief cells and sustentacular cells - T

Answer 111

4. Dandy Walker 6. Which is least likely to involve the corpus callosum: (GC) 1. GBM T - most commonly spread via direct extension along WM tracts, including the CC - classic butterfly pattern. 2. Marchifava Bignami T - primarily affects the CC - acute form affects the genu & splenium, chronic form affects the body. 3. DAI T - classic triad of GW junction, dorsolateral brainstem, and CC (most commonly eccentrically and in the splenium). 4. Dandy Walker F - assocd with dysgenesis of the CC in 20-25% (cf. primary involvemt) 5. Lymphoma T - differ from GBM as usually less peritumoral oedema, less often necrotic, highly radiosensitive, frequently respond dramatically to steroids. [AJR 2002]

Answer 112

4. Pleomorphic xanthoastrocytoma - F - rare distinct astrocytoma subtype tumor of children and young adults. Astrocytic tumor. 6. Which is not a mixed neural/glial tumour? (TW) 1. Ganglioglioma - T - benign tumor composed ofneoplastic astrocytes and ganglion cells. 2. DNET - T - mixed neuronal-glial neoplasm of infancey with a distinct desmoplastic component. 3. Lhermitte Duclos - T - dysplastic gangliocytoma of cerebellum - very rare, tumor-like neuronal lesion of the cerebellum, with distincet dysplastic features. 4. Pleomorphic xanthoastrocytoma - F - rare distinct astrocytoma subtype tumor of children and young adults. Astrocytic tumor. 5. Neurocytoma - T - Interventricular tumor composed of uniform round cells with immunihistochem an ultrastructural features of neuronal differentiation. Arises from septum pellucidum. Neuroglial tumors - nerve cells and glial cells of the brain come from a primitive neuroepithelial precur cell and germinal matrix. Pure neurons = ganglion cells (gangliocytoma, neurocytoma). Tumors of oligodendrocytes and astrocytes may be combined with ganglion cells and called gangliogliomas. If abnormalities which are considered to incorporate all these tumor types - can be called neuroepithelial tumors (DNET).

Answer 113

b. Warthins tumour - T - benign neoplasm. Distinctive double layer of lining cells with surface palisade of columnar cells having abundant, finely granular, eosinophilic cytoplasm, imparting an oncocytic appearance, resting on a layer of cuboidal to polygonal cells. 60. 55 yr old man with oncocytes from biopsy of a solitary parotid cyst? (TW) a. Benign pleomorphic adenoma - F - heterogeneity. Epithelial elements resembling ductal cells or myoepithelial cells disposed in duct formations, acini, irregular tubules, strands, or sheets of cells. b. Warthins tumour - T - benign neoplasm. Distinctive double layer of lining cells with surface palisade of columnar cells having abundant, finely granular, eosinophilic cytoplasm, imparting an oncocytic appearance, resting on a layer of cuboidal to polygonal cells. c. HIV. d. Type 1 Branchial cleft cyst - F - fibrous walls usually lined by stratified squamous or pseudostratified columnar epithelium underlaid by an intense lymphcytic infiltrate or, more often, well-developed lymphoid tissue with reactive follicles. e. Mucoepidermoid - F - mucus secreting cells, often forming glandular spaces. Higher grade tumors are composed of squamous cells with only a scatterin gof mucus-secreting cells.Oncocytes are epithelial cells stuffed with mitochondria that impart the granular appearance to the cytoplasm.

Answer 114

b. Papillary RCC

Answer 115

d.Adrenal tissue under the renal capsule is an example of a choristoma- T - normal cells or tissues in an abnormal location. 63. Which of the following are true in regards to choristomas and hamartomas? (TW) a. A hamartoma is an ectopic rest of tissue- F - Tumor-like malformation with tissues of a particular part of the body arranged haphazardly, usually with excess of one or more of its components. Excessive but focal overgrowth of cells and tissues native to the organ in which it occurs (cf teratoma - tissues NOT specific to the part) b. A choristoma is abnormal tissue in a normal location - F - AKA heterotopia. Normal cells or tissues that are present in abnormal locations. eg rest of pancreatic tissue found in the wall of the somtach or small intestine, or small mass of adrenal cells found in the kidney, lungs, ovaries, or elsewhere. The heterotopic rests ore usually of little significance, but can be confused clinically with neoplasms. c. An adenoma is a typical hamartoma - F - adenoma is a benign tumor of glandular origin d.Adrenal tissue under the renal capsule is an example of a choristoma- T - normal cells or tissues in an abnormal location. e. Hamartomas predispose to an increased risk of malignant transformation - F - not neoplastic. No tendency to excessive growth, being co-ordinated with surrounding tissues and stops after adolescence.

Answer 116

Answer:4. Depletion of oligodendrocytes is a feature of MS lesions (Loss of myelin & oligodendrocytes) 7. 90.APRIL02 Concerning CNS demyelination, which of the following statements is correct: 1. Acute disseminated encephalomyelitis (ADEM) typically follows a bacterial infection (viral) 2. Central pontine myelinosis is due to rapid correction of hyperkalaemia (Caused by rapid correction of hyponatraemia or extreme serum hyperosmolarity) 3. Multiple sclerosis lesions do not involve the corpus callosum (Corpus callosum in 50 – 90%) 4. Depletion of oligodendrocytes is a feature of MS lesions (Loss of myelin & oligodendrocytes) 5. Multiple sclerosis increases in frequency with HIV

Answer 117

2. Caudate nucleus T - striking atrophy (heart or box-shaped frontal horns), less dramatic change in the putamen. 7. Huntington’s chorea, what does it show: (GC) Autosomal dominant with complete inheritance, increased CAG trinucleotide repeats in huntingtin gene located on chromosome 4. 1. Various locations including basal ganglia F - although the globus pallidus may secondarily atrophy, with dilatation of the lateral and third ventricles. 2. Caudate nucleus T - striking atrophy (heart or box-shaped frontal horns), less dramatic change in the putamen. 3. Brainstem and Cerebellum F 4. Locus ceruleus, amygdala and basal ganglia F 5. Substantia nigra F - Parkinson's disease: pallor of the substantia nigra and locus ceruleus, Lewy bodies microscopically. [Robbins, Dahnert]

Answer 118

Answer: Cerebellar vermis (least likely finding) FROM STATDX - >85% periventricular/perivenular (Dawson Fingers) callososeptal interface - Brachium pontine, brainstem, spinal crd - Infratentorial (<10% in adults) - Gray matter (cortex & basal ganglia 10%) - Juxtacortical - Cerebellar white matter (penduncles are classic).

Answer 119

ANSWER:d. Decreased N-myc amplification T - less copies of gene is better 7. Neuroblastoma, which is not associated with a worse prognosis: (GC) a. Age > 1 year F - age < 1yr has a better prognosis b. Stage 4B F - stage 4S has a near 100% survival c. Abdominal primary F - thoracic primary has a better prognosis d. Decreased N-myc amplification T - less copies of gene is better e. Metastases to bone only F - mets to liver and skin is associated with better prognosis [Paeds pocket rad]Added options a-c and e.

Answer 120

*LW: See prior path / RD same question, both bacterial ADEM and demyelination are contentious, paper states demyelination likely occurs with DAI, and although rare case reports of ADEM post bacteria infection, however other than flipping a coin, I would go with ADEM follws bacterial infection as preferred answer with false (despite neither being mentioned in Robbins). 3. DAI causes demyelination - F - inertia forces - axos stretched, rarely disconnected or "sheared" (except only in most severe injury). Non-disrupted axons undergo traumatic depolarization, metabolic alterations, cellular swelling and cytotoxic oedema. "autoaxotomy". See below 7. Of demyelinating disease, which is false? (TW) 1. ADEM follows a bacterial infection - T - most patients it follow a viral illness, but has been reported after bacterial infection, immunizations, and drug and serum administration. 2. DAI causes demyelination - F - inertia forces - axos stretched, rarely disconnected or "sheared" (except only in most severe injury). Non-disrupted axons undergo traumatic depolarization, metabolic alterations, cellular swelling and cytotoxic oedema. "autoaxotomy". See below 3. MS is perivenular - T - perivenous demyelination, oligodendrocyte destruction. 4. Rasmussen encephalitis is typically unilateral - T - unilateral progressive cortical atrophy

Answer 121

ANSWER:4. majority of newborns have systemic signs of disease, of which about half have CNS involvement - F - most infected newborns appear normal. 10% have systemic signs of disease (hepatosplenomegaly, petechiae, chorioretinitis, jaundice, and IUGR). 55% with systemic disease have CNS involvement (microcephaly, parenchymal Ca+, SNHL, seizures, hypotonia or hypertonia). 7. Sep03.17 CMV encephalitis: which is false? (TW) 1. characteristic inclusions - T - CMV inclusion-bearing cells. Prominent cytomegatic cells with intranuclear and intracytoplasmic inclusions can be readily identified. Hallmark is cytomegaly with viral nuclear and cytoplasmic inclusions. 2. ependymal & subependymal involvement - T - may affect any cell type by striking tendency for virus to localise in teh epehdymal and subependymal regions of brain. Replicates in ependyma, germinal matrix, and capillary endothelia. 3. may cause haemorrhage - T - results in severe necrotising ventriculo-encephalitis with massive necrosis, haemorrhage, ventriculitis and choroid plexusitis 4. majority of newborns have systemic signs of disease, of which about half have CNS involvement - F - most infected newborns appear normal. 10% have systemic signs of disease (hepatosplenomegaly, petechiae, chorioretinitis, jaundice, and IUGR). 55% with systemic disease have CNS involvement (microcephaly, parenchymal Ca+, SNHL, seizures, hypotonia or hypertonia).

Answer 122

2. Lewy bodies F - eosinophilic intracytoplasmic inclusions found in some neurones in Parkinson's disease.

Answer 123

1. Fatty accumulation – ?T – denervation – fatty replacement With ALS the increasing signal in muscle is due to (TW) 1. Fatty accumulation – ?T – denervation – fatty replacement 2. Deposition of lipofuscin – F – lipofuscin deposition in the motor neurons

Answer 124

2. large acetabular angles - F - flattening of acetabular roof (small acetabular angle). Flaring of iliac wings "mickey mouse ears" / " elephant ears". Decreased iliac angle. 8) Downs, false (TW) 1. hypotelorism - T - also have hypoplasia of sinuses and facial bones 2. large acetabular angles - F - flattening of acetabular roof (small acetabular angle). Flaring of iliac wings "mickey mouse ears" / " elephant ears". Decreased iliac angle. 3. brachycephaly - T - microcrania. 4. metaphyseal flaring - T

Answer 125

Answer:3. They do not result in hydrocephalus (100% have ventriculomegaly) 8. 91.APRIL02 Concerning central neurocytomas, which of the following statements IS INCORRECT: 1. They arise in the region of the septum pellucidum (Lateral ventricle adjacent to foramen of Monro and septum pellucidum, occasionally involves 3rd ventricle, rarely alone) 2. Histologically (H&E stain) they resemble oligodendrogliomas (Mistaken for intraventricular oligodendroglioma on imaging & histologically – indistinguishable) 3. They do not result in hydrocephalus (100% have ventriculomegaly) 4. They present in young adults (Young adults (20 – 40 yrs)) 5. Calcification is common (> 60% have calcification)

Answer 126

3. Neuropathic – T – neuropathic joint. Loss of proprioception and vibration sense, but preservation of temperature and sensation. So I guess painful Charcot joint. Autosomal recessive degenerative disorder. Most common hereditary ataxia. Primary affects CNS, spinal cord, and peripheral nerves, as well as the heart and pancreas. Most cases caused by loss of function mutations in frataxin gene. Early loss of position and vibration sense and reflects posterior column spinal cord dysfunction as well as dorsal root and peripheral, primarily sensory, axonal neuropathy. Pain and temperature sensation are retained.

Answer 127

Answer: peripheral arterial FROM RADIOPAEDIA (Scant info on robbins/statdx) Most common sites are - Thoracic and abdominal aorta - abdominal visceral arteries - lower extremities arteries (femoral artery most frequently involved and associated with IVDU - Intracranial arteries: typically more peripheral than berry aneurysms (M2 and beyond). Intracranial mycotic aneurysms - primary risk factor: left sided IE (70% cases) - aetiology: bacterial (S. viridian, S. aureus). rarely fungal/viral. - location: peripheral branch points 2/3s. proximal branch points 1/3. - even with management, prognosis is poor, unruptures mortality 30%, ruptured mortality 80%.

Answer 128

4. Hypothalamus Most lesions occur in or near the midline. Commonest locations: cerebellum, hypothalamus (around 3rd ventricle), optic n./chiasm. In adults the tumour more frequently occurs in the cerebral hemisphere. Of all patients with an optic pathway glioma, 1/3 have NF-1, and of all tumours in this region 40-70% occur in NF-1 patients. [RG 2004]

Answer 129

2. Angioneogenesis T - WHO grade IV. Supratentorial PNETs had highly branched capillaries with extensive endothelial cell hyperplasia. Glomeruloid arrays of microvessels extended from the capillaries. Small fragments of endothelial tubes were scattered throughout the tumor. [Different vascular patterns of medulloblastoma & supratentorial PNETs. Internat J of Dev Neuroscience 1999] 8. PNET, which is the most typical appearance: 1. Cortical F - deep cerebral white matter, most commonly frontal lobe. 2. Angioneogenesis T - WHO grade IV. Supratentorial PNETs had highly branched capillaries with extensive endothelial cell hyperplasia. Glomeruloid arrays of microvessels extended from the capillaries. Small fragments of endothelial tubes were scattered throughout the tumor. [Different vascular patterns of medulloblastoma & supratentorial PNETs. Internat J of Dev Neuroscience 1999] 3. Cystic - Eric had this as the answer in 2004 - F - large (hemispheric) heterogeneous mass with tendency for necrosis (65%), cyst formation, calcification (71%), haemorrhage (10%). 4. Vasogenic oedema F - thin rim of oedema 5. Astrocytoma

Answer 130

2. periventricular veins - T - early lesion often centered on small veins, esp near ventricles and expansion often tracks along such vessels.

Answer 131

Answer: CJD patients live for <12 months. vCJD patients live for a few years. CJD - most common prior disease - sporadic form accounts of 90% of cases - familiar form caused by mutations in PRNP - peak incidence in 7th decade. - disease uniformly fatal. average survival 7 months after onset of symptoms - progression so rapid that is is little if any gross brain atrophy. - rapidly progressing, fatal, potentially transmissible dementing disorder caused by a prion (proteinaceous infectious particle devoid of DNA and RNA) vCJD - appeared in 1995 in UK - linked to exposure to bovine spongiform encephalopathy. - affected young adults - behavioural disorders figured more prominently in early stage of disease - neurological syndrome progressive more slowly than other forms of CJD (survival mean 14 months)

Answer 132

Answer: 1. Wernicke’s encephalopathy 9. 23.02.25 Chronic alcoholic presents with nystagmus, ophthalmoplegia, ataxia, but with preserved speech, no facial droop. What is likely diagnosis? Rob p839 1. Wernicke’s encephalopathy 2. Marchiafava Bignami syndrome (Onset is usually insidious, with the most common symptom be¬ing nonspecific dementia) 3. Korsakoff’s syndrome (Severe amnesia, causing confabulation, while patient remains alert & responsive) 4. Cerebellar infarct (will have dysarthria) 5. Osmotic pontine myelinosis ("locked-in" state) • Wernicke encephalopathy is marked by ophthalmoplegia; nystagmus; ataxia of gait and stance; and derangement of mental function, characterized by global confusion, apathy, listlessness, and disorientation • MRI findings are characteristic and include T2 hyperintensity within the medial thalamic nuclei (46%), the periaqueductal gray matter (40%), and the mamillary bodies. The acute lesions may enhance. Mamillary body abnormal signal intensity &/or enhancement may be the only finding of WE.

Answer 133

3. Lysosomal storage disorder – F – mitochondrial disorder characterised by neurodegeneration. Brain and striated muscle highly dependent on oxidative phosphorylation which are moste severely affected in mitochondrial disorders. . Leighs, which is incorrect… (TW) 1. Increased T2 signal in peri-aqueductal gray matter – T – best diagnostic clue = bilateral, symmetric increased T2/FLAIR in putamina and peri-aqueductal gray matter 2. Enhancement is uncommon - T 3. Lysosomal storage disorder – F – mitochondrial disorder characterised by neurodegeneration. Brain and striated muscle highly dependent on oxidative phosphorylation which are moste severely affected in mitochondrial disorders. 4. May be x-linked inheritance – Autosomal recessive, X-linked, and maternal inheritance of mutated proteins involved in mitochondrial energy production underlie Leigh syndrome. 5. Most present by 2y age – T – majority by 2yo.

Answer 134

Answer: Shy Drager Shy Drager - known as multiple system atrophy. - Sky-Drager syndrome still used sometimes for MSA when primary symptoms are autonomic failure. MSA - striatonigral degeneration is clinically similar to idiopathic PD in presentation, but is relatively resistent to L-dopa treatment (due to pattern of neuronal degeneration - ie both dopaminergic projections and its target neurons are absent, therefore L-dopa cannot bulster neurotransmission as occurs in parkinsons disease).

Answer 135

ANSWER:4. HIV positive - F - this is probably rare, however ADEM has been assoc with HIV-seroconversion illness. Probably getting you to Dx from PML. 9. Patient with possible ADEM. Which clinical setting least likely? (TW) 1. 2 week history of viral illness - T - monophasic (usually) demyelinating disease following either a viral infection, or, rarely, a viral immunisation. Typically develops a week or two after anticedent infection. 2. female - T - common finding. Male predominance reported in some series 1.3 : 1 3. headache and confusion progressing to coma in 48 hrs - T - usually fever, malasie, myalgia as prodromal phase. Then headache, fever, drowsiness. Can have cranial nerve palsies, seizures, hemiparesis, decreased consciousness (from lethargy to coma). 4. HIV positive - F - this is probably rare, however ADEM has been assoc with HIV-seroconversion illness. Probably getting you to Dx from PML. 5. Age less than 40 - T - peak age 3-5yo, but can occur at anytime

Answer 136

Answer: Involvement of posterior 2/3 superior temporal gyrus & parietal lobe. (Uncommon finding) FROM ROBBINS Pick Disease - Pronounced frequently asymmetric atrophy of the fontal and temporal lobes with conspicuous sparing of the posterior 2/3s of the superior temporal gyrus and only rare involvement of either parietal or occipital lobe - atrophy can be severe, reducing gyro to wafer-thin ("knife-edge"_ appearances. - surviving neurone show a characteristic swelling (Pick Cells), while others contains Pick Bodies. Frontotemporal lobar degenerations (FTDLs) - heterogenous set of disorders with focal degeneration of the frontal and/or temporal lobes. - Distinguished from AD by the fact that alterations in personality behaviour and language (aphasias) precede memory loss. - Include FTLD-Tau (which includes Pick disease) and FTLD-TDP. - 25-40% of FTD is familial. 10-30% of patients with positive family history have tau mutations (Tauopathy).

Answer 137

*AJL - I favour chicken pox to not be a congenital infection, it is never mentioned in robbins. The rest are counted as TORCH (Toxo, other (syphilis, ...), Rubella, CMV, Herpes). 5. Herpes - In utero infection is rare; 3% of these will have severe symptoms of skin vesicles/scarring, eye disease, microcephaphaly/hydranencephaly. HSV-2 is most commonly acquired during vaginal delivery (intrapartum), can also occur postnatally (horizontal transmission). 9. Which of the following is not a congenital CNS infection: (GC) see Aug 2007 1. Chicken pox Eric had this as the answer in 2004 - Dahnert includes it in "Other", p232.? T - Congenital varicella syndrome occurs in 2% of children born to women who develop varicella during the 1st or 2nd trimester of pregnancy. Manifests as IUGR, cortical atrophy, microcephaly, microphthalmia, cataracts, limb hypoplasia, skin scarring. 2. Rubella 3. CMV 4. Toxoplasmosis 5. Herpes - In utero infection is rare; 3% of these will have severe symptoms of skin vesicles/scarring, eye disease, microcephaphaly/hydranencephaly. HSV-2 is most commonly acquired during vaginal delivery (intrapartum), can also occur postnatally (horizontal transmission).

Answer 138

3. 4 x > common than medulloblastoma 1. Ependymoma – which is false: (GC) 1. Poor prognosis T - current 5YS rate for patients with intracranial ependymomas is approximately 50%, when rates from children and adults are combined. Stratification based on age reveals 5YS rates of 76% in adults (mainly spinal tumours) and only 14% in children (mainly intracranial tumours; 70% infra-, 30% supratentorial). 2. Have drop mets T - GEM POT. Subarachnoid dissemination via CSF is observed in <10% of patients at diagnosis when ependymoblastomas are excluded. The incidence is higher with infratentorial ependymomas than with supratentorial tumors (9% vs 1.6%). 3. 4 x > common than medulloblastoma F - third most common paediatric brain tumour, after medulloblastoma & JPA. 4. 4th ventricle T - In children, approximately 90% of ependymomas are intracranial - 70% infratentorial (usually arising from roof of 4th ventricle), 30% supratentorial. In adults and adolescents, 75% arise within the spinal canal. [eMedicine, Adelaide notes]

Answer 139

. Cord involvement F - can't find any literature on this. 1. Central pontine myelinolysis, which is least correct: (GC) a. Oesophageal varices T - 60-70% of CPM occurs in chronic alcoholics, who are more likely to have chronic liver disease and varices. b. Cord involvement F - can't find any literature on this. c. Resuscitation with IV fluids if hypotensive T - aggressive IVH with hypertonic saline solutions may precipitate CPM. However, many patients with hypoNa+ that is corrected rapidly do not develop CPM. d. Supratentorial involvement T - extrapontine myelinolysis: BG, thalamus, caudate nucleus, subcortical cerebral WM, corona radiata, lateral geniculate body. Also may occur in cerebellar WM. e. Recent quadriparesis T - spastic quadriplegia, pseudobulbar palsy & "locked-in" state. [eMedicine, Dahnert 6th p273] Changed Qu from "least likely", changed option d. from "supracortical"

Answer 140

2. Fat soluble medium cannot pass if normal BBB F - lipophilic solutes do not have a significant affinity for plasma proteins and are able to pass into the luminal plasma membrane lipid with ease, and hence into the brain.

Answer 141

Haemorrhage is uncommon – T – rare to get haemorrhagic foci (0.5%). 1. Regarding vestibular schwannomas: (TW) 1. Bilateral tumours are associated with NF1 – F – NF2 = MISME, multiple inherited schwannomas, meningiomas, and Ependymomas. 2. Haemorrhage is uncommon – T – rare to get haemorrhagic foci (0.5%). 3. About 70% are cystic – F – 15% have intramural cysts (Harnsberger) 4. Meningeal reaction is typical – F – this is a differentiating factor to Dx from meningioma. 5. A melanotic variant is a recognized entity – F - CME says F. However there are a handful of cases reported (so very, very rare). Melanotic schwannoma is a rare melanin-producing nerve sheat tumor. MSs are of neural crest origin, prob from neoplastic proliferation of a common precursor cell for both Schwann cells and melanocytes. Most involve cranial or spinal nerve roots (esp spinal Cx and thoracic nerves). 10% involve symp chain. There have been reports of MSs of vestibular nerves. MSs may be component of Carney complex.

Answer 142

a. Hurthle cells -T - mononuclear inflammatory infiltrate containing small lymphocytes, plasma cells, and well-developed germinal centers. The thyroid follicles are small and are lined in many areas by epithelial 58. Autopsy of the thyroid in Hashimotos shows? (TW) a. Hurthle cells -T - mononuclear inflammatory infiltrate containing small lymphocytes, plasma cells, and well-developed germinal centers. The thyroid follicles are small and are lined in many areas by epithelial cells with abundant eosinophilic, granular cytoplasm, termed Hurthle cells. b. Fibrosing nodules - F - Reidel's thyroiditis. c. Psammoma bodies - F - in papillary thyroid carcinoma. Concentrically calcified structures.

Answer 143

d. Riedels Thyroiditis - F - rare, chronic inflammatory disease of thyroid gland characterized by a dense fibrosis that replaces normal thyroid capsule. Morbidity is most frequently related to local compressive symptoms. Most patients are euthyroid, and hypothyroidism can be seen in 30% cases. 61. Least likely to cause Hyperthyroidism? (TW) a. Graves disease - T - thyroid stimulating antibodies. Elevated T3 and T4. b. Toxic adenoma - T - AKA Plummer disease / toxic autonomous nodule. Hyperthyroidism caused by one / two hyperfunctioning nodules independent of normal pituitary-thyroid control. c. Hashimotos thyroiditis - T - thyrotoxicosis in early stage 4%. Hypothyroid at presentation 20%. Chronic lymphocytic thyroidits. Autoimmune process with marked familial predisposition. d. Riedels Thyroiditis - F - rare, chronic inflammatory disease of thyroid gland characterized by a dense fibrosis that replaces normal thyroid capsule. Morbidity is most frequently related to local compressive symptoms. Most patients are euthyroid, and hypothyroidism can be seen in 30% cases. e. Subacute thyroiditis - T - AKA subacute thyroiditis. Hyperthyrodisim 50% secondary to severe destruction. Short-lived hypothyroidism (25%) due to hormone depletion of gland. Probably viral aetiology. Lymphocytic infiltration, granulomatous and foreign body giant cells.

Answer 144

contrast enhancement of the para hippocampal gyrus - F – no enhancement. 1) Mesial temporal sclerosis, which is false (TW) 1. contrast enhancement of the para hippocampal gyrus - F – no enhancement. 2. atrophy hippoc gyrus – T – decreased size of hippocampus 3. may see fornix and/or mamillary body atrophy – T – location: mesial temporal lobe – hippocampus > amygdale > fornix > mamillary bodies. Bilateral in 20% cases. 4. dilatation of temporal horn may be evident - T

Answer 145

2. Fat soluble medium cannot pass if normal BBB F - lipophilic solutes do not have a significant affinity for plasma proteins and are able to pass into the luminal plasma membrane lipid with ease, and hence into the brain. *EDWH - I think this is wrong, if you read the answers they are contradicting, saying that water soluble medium can’t cross and lipophilic can. Radiopaedia says “Hydrophilic solutes, in general, are unable to cross it, e.g. water soluble CT/MRI contrast media.” And “Generally, lipophilic solutes can cross the blood-brain barrier” - thus I think the answer is 1, water soluble medium cannot pass if normal BBB BBB, which is incorrect: (GC) 1. Water soluble medium cannot pass if normal BBB T - solutes with high affinity for plasma water, low affinity for plasma proteins, and high extremely low partition coefficients do not penetrate normal BBB (eg. contrast media). 2. Fat soluble medium cannot pass if normal BBB F - lipophilic solutes do not have a significant affinity for plasma proteins and are able to pass into the luminal plasma membrane lipid with ease, and hence into the brain. 3. Capillaries are continuous T - this is the basis of the BBB. Other types are fenestrated (circumventricular organs), and sinusoidal (liver, spleen, bone marrow). 4. Continuous capillaries have no fenestrations T - wall is composed of a single layer of endothelial cells connected by tight junctions, surrounded by a continuous basement membrane. It is the continuity of the interendothelial tight junctions, lack of pinocytosis and absence of fenestrations that contribute to the restricted permeability of the BBB. 5. Tight junctions are important T - see above.

Answer 146

2. Liquefactive - T - characteristic of focal bacterial or occasional fungal infections, as these agents constitute powerful stiumli to the accumulation of inflammatory cells. Hypoxic death of CNS cells often evokes liquefactive necrosis. Liquefactin completely digests the dead cells. Tranformation of tissue into liquid viscous mass. Which form of necrosis is seen with cerebral infarction (TW) 1. Coagulative - F - implies preservation of the basic outline of coagulated cell for a span of at least some days. Myocardial infact is typical example - ultimatley the necrotic myocardial cells are removed by fragmentation and phagocytosis of cellular debirs by scavenger cells and lysosomal enzymes. This type of necrosis is characteristic of hypoxic death of cells in all tissues except the brain. 2. Liquefactive - T - characteristic of focal bacterial or occasional fungal infections, as these agents constitute powerful stiumli to the accumulation of inflammatory cells. Hypoxic death of CNS cells often evokes liquefactive necrosis. Liquefactin completely digests the dead cells. Tranformation of tissue into liquid viscous mass. 3. Caseous - F - distinctive form of coagulative necrosis. Most often in foci of tuberculous infection. 4. Gummatous - F- restricted to necrosis involving spirochaetal infections (syphilis)

Answer 147

Answer: Anaplastic thyroid cancer in a 29 year old (most atypical scenario) Anaplastic thyroid cancer - undifferentiated tumors of the thyroid follicular epithelium - <5% of thyroid tumors - aggressive, mortality approaching 100% - mean age 65 years old - 1/4 of cases have a past history of well-differentiated thyroid carcinoma Craniopharyngioma - vestigial remnant of Ranthke Pouch - slow growing tumor - bimodal age: 5-15 years, then >65 years. - sx: headaches and visual disturbances. Children growth retardation. - 2 distinct histologic variants: Adamantinomatous & papillary - Adamantinomatous: most common in children - Papillary: most communion adults. - <5 cm: excellent prognosis. Bowel Cancerin a 32 year old - pre-existing IBD or polyposis syndromes Cholangiocarcinoma in a young adult with emphysema - a1-antitrypsin deficiency predisposed to cholangiocarcinoma.

Answer 148

b. Paragangliomas are parasympathetic tumours - F - rare neuroendocrine tumors arising from paraganglionic tissue found between base of skull and floor of pelvis. Adrenal paraganglioma = phaeochromocytoma, extraadrenal paraganglioma sympathetic / parasympath **LJS - agree, paragangliomas can be SNS or PSNS 62. Which of the following is false? (TW) a. Chordomas arise from physaliphorous cells - T - arise from embryonic remnants of the primitive notochord. Microscopically, cordomas are composed of characteristic mucoid, fluid-containing, translucent cells of variable size with a large, intracytoplasmic vacuole, and they are rich in mucin and glycogen (physaliphorous cells) b. Paragangliomas are parasympathetic tumours - F - rare neuroendocrine tumors arising from paraganglionic tissue found between base of skull and floor of pelvis. Adrenal paraganglioma = phaeochromocytoma, extraadrenal paraganglioma sympathetic / parasympath c. Cholestrol granulomas need an aerated pterous apex for formation - T - results from obsturction of the normal aeration of petrous air cells. d. Cholestatomas arise from epithelial rests - T - derived from aberrant embryonic ectodermal rests in temporal bone (primary, AKA epidermoid cyst). Ingrowth of squamous epithelium throught tympanic membrane secondary to repeated inflammation / marginal perforation of ear drum.