Neuropathology Flashcards
1
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Acute Neuronal Injury (red neuron)
A
Acute CNS hypoxia or ischemia or acute insults reflect cell death, necrosis or apoptosis
- shrink cell body, pyknosis of nucleus, disappearances of nucleolus, loss of Nissl, eosinophilia of cytoplasm
2
Q
Subacute and chronic neuronal injury
A
Cell loss with reactive gliosis
3
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Axonal reaction
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Increased protein synthesis associated with axonal sprouting
- enlargement and rounding of cell body, peripheral placement of nucleus, nucleolus enlargement, dispersion of Nissl
4
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Rosenthal fibers
A
Thick, elongated, brightly eosinophilic, irregular structures in astrocytes
- found in gliosis and glial tumor –> pilocytic astrocytoma
5
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Corpora amylacea
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Basophilic, PAS lamellated structures with astrocytic end processes in subpial and perivascular zones
- degenerative change in astrocyte
6
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Alzheimer Type II astrocytes
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gray matter cell with large nucleus, pale chromatin, intranuclear glycogen droplet, nuclear membrane and nucleolus
- hyperammonemia from chronic liver disease, wilson disease, metabolic disorders hereditary of urea cycle
7
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Ependymal granulations
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Inflammation or dilation of ventricular system leads to small irregularities in ventricular surfaces
- ex: CMV
8
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Microglial response to injury
A
Steps:
- proliferative
- develop elongated rod cells
- form aggregates about small foci of tissue necrosis (microglial nodules)
- congregating around cell bodies of dying neurons (neuronophagia)
9
Q
Vasogenic edema
A
blood brain barrier disruption with increased vascular permeability
- fluid to shift from intravascular to intercellular spaces of brain
10
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Cytotoxic edema
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increase in intracellular fluid secondary to neuronal, glial, endothelial cell membrane injury
11
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Interstitial edema
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increase in intravascular pressure causing abnormal flow of fluid from intraventircular CSF
12
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Noncommunicating hydrocephalus
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portion of ventricular system enlarged from excess CSF i.e. mass in third ventricle
13
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Communicating hydrocephalus
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Enlargement of entire ventricular system
14
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Hydrocephalus ex vacuo
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Dilation of ventricular system with compensatory increase in CSF volume secondary to loss of brain parenchyma
15
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Hydrocephalus in infants and children
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enlargement of head and increased head circumference
16
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Subfalcine herniation
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unilateral or asymmetric expansion of cerebral hemisphere displaces cingulate gyrus under falx cerebri –> can compress ACA
17
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.Transtentorial herniation
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Medial aspect of temporal lobe compressed against tentorium –> can compromise cranial nerve three or PCA
18
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Tonsillar herniation
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Displacement of cerebellar tonsils through foramen magnum –> brainstem compression and compromises viral respiratory and cardiac centers in medulla oblongata
19
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Spina Bifida Occulta
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Failure of closure or reopening of caudal neural tube –> asymptomatic bony defect
20
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Meningocele
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Extension of meningeal extrusion
21
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Myelomeningocele
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Extension of CNS tissue through a defect in vertebral column in lumbosacral region
- motor and sensory disturbances of bowel and bladder control
22
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Encephalocele
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Diverticulum of malformed CNS tissue through a defect in cranium –> occipital region or posterior fossa
23
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Anencephaly
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Malformation of anterior end of neural tube with absence of brain and calvarium
24
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Lissencephaly
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Absence of gyri, leads to a smooth surfaced brain
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Polymicrogyria
Small unusually numerous and irregular cerebral convolutions
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Neuronal heterotopias
Migrational disorders associated with epilepsy --> collections of neurons in inappropriate locations along migrational pathways
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Holoprosencephaly
Spectrum of malformations from incomplete separation of cerebral hemispheres across midline
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Agenesis of corpus callosum
Absence of white matter bundles with misshapen lateral ventricles
- associated with mental retardation or normal
29
Dandy-walker Malformation
Enlarged posterior fossa, cerebellar vermis absent, instead midline cyst is there
30
Arnold Chiari Type II Malformation
Small posterior fossa, misshapen cerebellum with downward vermis through foramen magnum, hydrocephalus, lumbar myelomeningocele
- caudal displacement of medulla, malformation of tectum, aqueductal stenosis, cerebral heterotopias, hydromyelia
31
Syringomyelia
Formation of fluid-filled cleftlike cavity in inner portion of cord which may extend into brainstem
- isolated loss of pain and temperature in upper extremities
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Hydromyelia
Expansion of ependyma lined central canal of cord
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Cerebral Palsy
Nonprogressive neurologic motor deficit from spasticity, dystonia, ataxia/athetosis, paresis
- increased risk of intraparenchymal hemorrhage in germinal matrix
- infarcts in supratentorial periventricular white matter (periventricular leukomalacia)
34
Concussion
Clinical syndrome of altered consciousness secondary to head injury from change in momentum of head
35
Epidural hematoma
Middle meningeal artery vulnerable to injury with temporal skull fractures with extravasation of blood under arterial pressure causing dura to separate from inner surface of skull
36
Subdural hematoma
Inner surface of dura and outer arachnoid layer from bridging veins
- acute --> fresh clotted blood on brain surface, underlying brain flattened
- chronic --> episodes of repeat bleeding
37
Border zone (watershed) infarct
Occur at regions of brain distal of arterial blood supply
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Majority of Thrombotic Occlusions
Due to atherosclerosis
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Embolism
Paradoxical emboli from tumor, fat, or air --> cardiac surgery/ cardiac anomalies
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Infectious vasculitis
small and large vessels associated with syphilis and tuberculosis --> immunosuppression
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Hemorrhagic (red) infarction
mutliple, sometimes confluent, petechial hemorrhages associated with embolic events
42
Nonhemorrhagic infarction
Pale, bland, anemic associated with thrombosis
43
Lacunar infarct
CNS arterial lesion from HTN arteriolar sclerosis as single or multiple, small, cavitary infarcts
- occurs in lenticular nucleus and pons
44
Acute hypertensive hemorrhage
malignant hypertension can lead to diffuse cerebral dysfunction
- sx: headache, confusion, vomiting, convulsions, coma
45
Charcot-Bouchard microaneurysms
Arteriolar walls affected by hyaline change in chronic hypertension
46
Saccular aneurysm
Can cause SAH, most common aneurysm
- found near major arterial branch points in anterior circulation
- increased incidence in polycystic kidney disease, Ehlers-Danlos type IV, neurofibromatosis type I, Marfan syndrome, coarctation of aorta
- cigarette and HTN predisposing
47
Arteriovenous malformations
Tangled network of wormlike vascular channels with prominent pulsatile arteriovenous shunting
- involve vessels in subarachnoid space
- increased risk of hemorrhage, most common
- males 2 x greater than females
48
Cavernous hemangioma
loosely organized vascular channels with thin collagen walls without nervous tissues
- occur in cerebellum, pons, subcortical regions
- increased risk of hemorrhage
49
Capillary telangiectasias
Microscopic foci of dilated, thin-walled vascular channels separated by normal brain parenchyma
- occur most frequently in pons
50
Foix-Alajouanine disease
venous angiomatous malformation of spinal cord and overlying meninges
- most often in lumbosacral region
- ischemic myelomalacia and slowly progressive neurologic symptoms
51
Bacterial meningitis
Neonates: E. coli and Group B strep
Adolescents: Neisseria meningitidis, Haemophilus influenzae
Old age: Strep pneumonia, Listeria monocytogenes
Sx: headache, photophobia, irritability, clouding of consciousness, neck stiffness
Spinal tap: purulent CSF, increased pressure, increased neutrophils, increased protein, decreased glucose
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Viral meningitis
Sx: headache, photophobia, irritability, clouding of consciousness, neck stiffness
Spinal tap: moderate elevated protein, normal glucose, sterile, pleocytosis with neutrophils
53
Brain abscess
Direct implantation (mastoiditis, paranasal sinusitis), hematogenous spread
- causes: acute bacterial endocarditis, congenital heart disease, chronic pulmonary sepsis, immunosuppression
- organism: strep and staph
- morph: liquefactive necrosis surrounded by fibrosis and swelling, capsule around produced by fibroblasts from walls of blood vessels with a zone of reactive gliosis on the outside
- sx: progressive focal deficits, raised intracranial pressure, raised WBC, increased protein, glucose normal
54
Subdural empyema
Bacterial or fungal of skull bones or air sinuses spreading to subdural space
- sx: mass effect, thrombophlebitis may develop in bridging veins with venous occlusion and infarct of brain
55
Tuberculosis
Chronic bacterial meningoencephalitis
- morph: gelatinous or fibrinous exudate most often at the base of the brain, obliterating cisterns, and encasing CN
- -> mixtures of lymph, plasma cells, macrophages with florid cases of well formed granulomas
- -> hydrocephalus may result
- tuberculoma: single well circumscribed intraparenchymal mass associated with meningitis
- sx: headache, malaise, mental confusion, vomiting
56
Neurosyphilis (3 types)
Chronic bacterial meningoencephalitis
- tertiary stage of syphilis
Meningeal neurosyphilis
- chronic meningitis involving base of brain
- associated with obliterative endarteritis --> perivascular inflammatory reaction in plasma cells and lymphocytes
- cerebral gummas
Paretic neurosyphilis
- insidious but progressive mental deficits associated with mood alterations and dementia
- loss of neurons, proliferation of microglia, gliosis, iron deposits
- granular ependymitis
Tabes dorsalis
- sensory nerves in dorsal roots, impaired joint position sense and resultant ataxia, loss of pain, absence of DTR
57
Arthropod borne viral encephalitis
Sx: seizures, confusion, delirium, stupor/coma, reflex asymmetry, ocular palsies
CSF: colorless, elevated pressure, neutrophilic pleocytosis convernts to lymph, protein elevated, glucose normal
Morph: microglial around foci of necrosis, nectrotizing vasculitis with associated focal hemorrhages
58
Herpes Simplex Virus Type I Encephalitis
Age: children and young adults
Sx: alterations in mood, memory, behavior, weakness, lethargy, ataxia, seizures
Morph: necrotizing hemorrhagic with perivascular inflammatory infiltrates with viral inclusion bodies in neuron and glia
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Cytomegalovirus
Age: fetus and immunosuppressed individuals
- neonates: microcephaly and periventricular calcification
Morph: periventricular necrosis, inclusion bearing cells
Sx: severe hemorrhagic necrotizing ventriculoencephalitis and choroid plexitis or radiculoneuritis
60
Poliomyelitis
Acute cases: mononuclear and neuronophagia of anterior horn motor neurons of the spinal cord
Sx: meningeal irritation and CSF aseptic meningitis
--> if progresses to spinal cord, flaccid paralysis with muscle wasting and hyporeflexia
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Rabies
Morph: intense edema and vascular congestion
- widespread neuronal degeneration and infl in brain stem
- Negri bodies are pathognomonic --> cytoplasmic, round to oval eosinophilic inclusions in pyramidal neurons of hippocampus and Purkinje cells of cerebellum
Sx: malaise, headache, fever, local paresthesias, meningismus, flaccid paralysis, mania, stupor, coma, death from respiratory center failure
62
HIV encecphalitis
Morph: Chronic inflammatory reaction with widespread infiltrates of microglial nodules with foci of tissue necrosis and reactive gliosis
- endo cells and perivascular foamy or pigment macro
- multinucleated giant cell
Sx: cognitive changes of dementia
63
Progressive multifocal leukoencephalopathy
Sx: demyelination principle effect, focal and relentlessly progressive neurologic symptoms and signs
Morph: destruction of white matter with scattered lipid laden macro and reduced number of axons
- glassy viral inclusion, bizarre giant astrocytes with irregular hyperchromatic nuclei mixed with astrocytes
64
Creutzfeldt-Jakob disease
Most common prion disease
Sx: rapidly progressive dementia, involuntary jerking muscle contractions on subtle stimulation, ataxia minorly
Path: mutation in PRNP, iatrogenic transmission
Morph: spongiform cerebral cortex, deep gray matter structures
- cystic spaces (status spongiosus)
- Kuru plaques --> extracellular deposits of aggregated abnormal protein, usually occur in cerebellum
65
Variant Creutzfeldt- Jakob disease
Age: young people
Sx: slower progressive neurologic symptoms
Morph: spongiform cerebral cortex, deep gray matter structures
- cystic spaces (status spongiosus)
- Kuru plaques --> extracellular deposits of aggregated abnormal protein, usually occur in cerebellum
66
Multiple sclerosis
Autoimmune demyelinating disorder with distinct neuro deficits
Gender: women more than men
Path: DR2 related as autoimmune disorder, initiated by CD4 TH1 and TH17 cells that react against self myelin antigens and secrete cytokines
Morph: depressed irregular shaped plaques, found throughout white matter and into gray matter
- active plaque has myelin breakdown with macro, infl cells, astrocytes reactive changes
- shadow plaques on border between normal and affected white matter not circumscribed
Sx: unilateral visual impairment, involved in optic nerve
- CN signs, ataxia, nystagmus, internuclear ophthalmoplegia from interruption of MLF
- motor and sensory impairment of trunk and limbs, spasticity, difficulties with bladder function
CSF: elevated protein level, moderate pleocytosis, increased IgG
67
Acute Disseminated Encephalomyelitis
Diffuse monophasic demyelinating disease following a viral infection
Sx: headache, lethargy, coma
Morph: myelin loss with preservation of axons
- polymorphonuclear leukocytes found within lesions with mononuclear infiltrates
- accumulation of lipid laden macro
- monophasic vs MS which is not
68
Central pontine myelinolysis
Loss of myelin with preservation of axons and neuronal cell bodies in a symmetric pattern of pons and ponteine tegmentum
- associated with rapid correction of hyponatremia
Sx: evolving quadriplegia
69
Alzheimer disease
Most common dementia in elderly (>50 yo)
- autosomal dominant
Path: beta secretase activity leads to Abeta plaques
- plaques aggregate and be neurotoxic
- apoE4 increases risk
Sx: insidious impairment of higher intellectual function with alteration in mood and behavior
- progressive disorientation, memory loss, aphasia, severe cortical dysfunction
Morph: cortical atrophy with widening of sulci in frontal, temporal, parietal lobes
- neuritic plaques --> spherical tortuous processes around a central amyloid core in hippocampus, amygdala, neocortex, Abeta peptide
- neurofibrillary tangles --> bundles of filaments in cytoplasm of neuron that displace or encircle nucleus, tau protein
- cerebral amyloid angiopathy, granulovacuolar degeneration, hirano bodies
70
Pick Disease
Progressive dementia characterized by early onset of behavioral changes with alterations in personality and language disturbances
Morph: asymmetric atrophy of frontal and temporal lobes
- lobar atrophy
- pick bodies are cytoplasmic round to oval filamentous inclusions that are weakly basophilic
- composed of straight filaments
71
Parkinsonism
Causes:
- Parkinson's disease
- multiple system atrophy
- postencephalitic parkinsonism
- progressive supranuclear palsy and corticobasal degeneration
72
Parkinson disease
Inheritance: AD or AR, deficiency of LDOPA
Morph: pallor of substantia nigra and locus ceruleus
- Lewy body in remaining neuron which are cytoplasmic, eosinophilic round inclusions
--> composed of alpha-synuclein
Sx: tremor, rigidity, bradykinesia, dementia
73
Huntington Disease
Inheritance: Auto Dominant
- progressive movement disorders and dementia with degeneration of striatal neurons (GABA)
Sx: jerky, hyperkinetic, dystonic movements, chorea --> can progress to parkinsonism
Path: CAG repeats of huntingtin disease, earlier sx depending on number of repeats
- dysregulation of basal ganglia from loss of medium spiny striatal neurons
Morph: atrophy of caudate nucleus with putamen; lateral and third ventricles dilated
74
Friedreich Ataxia
Inheritance: autosomal recessive progressive illness
Clinical: first decade - gait ataxia with clumsiness and dysarthria
- DTR depressed or absent, joint position and vibratory sense are impaired
- pes cavus and kyphoscoliosis
- associated with cardiac arrhythmias and CHF
Morph: expansion of GAA trinucleotide repeat encoding frataxin
- spinal cord shows loss of axons and gliosis in posterior columns, spinocerebellar tracts, corticospinal tracts
- brainstem, spinal cord, cerebellum and Purkinje cells of superior vermis and Betx cells
- heart enlarged
75
Amyotrophic Lateral Sclerosis
Loss of lower motor neurons in spinal cord, brainstem, upper motor neurons
- affects men more than women
Age: fifth decade or later
Genetics: Mutations in SOD1
Path: Reduced capacity to detoxify free radicals leading to neuronal death
Morph: anterior roots of spinal cord are thin, precentral gyrus atrophic
- reactive gliosis and loss of anterior root myelinated fibers --> hypoglossal, ambiguus, motor trigeminal CN nuclei
Sx: asymmetric weakness of hands --> difficulty in fine motor tasks and cramping spasticity of arms and legs
- fasciculations occur
- progressive muscular atrophy or bulbar palsy when it affects CN nuclei
76
Tay Sachs
Disease begins in early infancy with developmental delay, paralysis, loss of neuro function and death
77
Krabbe Disease
Inheritance: Autosomal recessive leukodystrophy
- deficiency of galactocerebroside beta-galactosidase --> leads to accumulation of galactocerebroside
Sx: rapidly progressive, death by age 2
- motor signs, stiffness and weakness with worsening difficulties in feeding
Morph: loss of myelin and oligodendroctyes in CNS and similarly in peripheral nerves
- engorged macrophages in parencyhuma and BV
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Metachromatic leukodystrophy
Inheritance: autosomal recessive
- deficiency of lysosomal enzyme arylsulfatase A
- accumulation of sulfatides leading to myelin breakdown
Age: late infantile form (most common), juvenile form, adult form
Sx: childhood - motor sx which progress gradually
- adult --> psychiatric or cognitive sx with motor sx later
Morph: demyelination with gliosis, macrophages with vacuolated vytoplasm scattered throughout white matter
- contain crystalloid structures composed of sulfatides
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Leigh Syndrome
Age: early childhood
- lactic acidemia with arrest of psychomotor development, feeding problems, seizures, extraocular palsies, weakness with hypotonia
- death occurs 1-2 years
Morph: symmetric regions of brain tissue with spongiform appearance and proliferation of blood vessels
- periventricular gray matter of midbrain, tegmentum of pons, thalamus and hypothalamus
Sx: neuropathy, ataxia, retinitis pigmentosa (NARP)
80
Thiamine (vit B1) deficiency
Causes beriberi --> associated with cardiac failure
Sx: psychotic symptoms or ophthalmoplegia begins abruptly as Wernicke encephalopathy
- can progress to Korsakoff syndrome --> memory disturbances and confabulation
Causes: chronic alcoholism, gastric disorders, persistant vomiting
Morph: hemorrhage and necrosis in mamillary bodies and third and fourth wall of ventricle
- infiltration of macro and cystic space with hemosiderin laden macro
81
Vitamin B12 deficiency
Anemia with severe effects on nervous system
Sx: numbness, tingling, ataxia in lower extremities, spastic weakness in lower extremities
- complete paraplegia
Morph: swelling of myelin layers producing vacuoles
- begins at midthoracis level of spinal cord
Clinical: subacute combined degeneration of the spinal cord
82
Hypoglycemia
Selective injury of large pyramidal neurons of cerebral cortex
- can lead to pseudolaminar necrosis of cortex
- hippocampus vulnerable may show in Sommer sector
83
Hyperglycemia
Inadequately controlled DM associated with ketoacidosis or hyperosmolar coma
Sx: dehydration, confusion, stupor, coma
84
Hepatic encephalopathy
Glial cells, Alzheimer type II evident in cortex and basal ganglia with subcortical gray matter regions
85
Carbon monoxide
Neurons in layer III and V of cerebral cortex, Sommer sector of hippocampus, purkinje cells
- bilateral necrosis of globus pallidus
- demyelination may be a later event
86
Methanol
Affects retina --> causes blindness
| - selective bilateral putamenal necrosis and focal white matter necrosis possible
87
Ethanol
Chronic alcohol abuse can lead to Wernicke-Korsakoff syndrome
- cerebellar dysfunction occurs in 1% of chronic alcoholics --> cerebellar ataxia, unsteady gait, nystagmus
Morph: atrophy and loss of granule cells in anterior vermis
- loss of purkinje cells and proliferation of adjacent astrocytes between granular cell layer and molecular layer of cerebellum
88
Radiation
Intractable nausea, confusion, convulsions, rapid coma and death
- delay: HA, nausea, vomiting, papilledema
Morph: large areas of coagulative necrosis and adjacent edema
89
Astrocytoma
Two categories: infiltrating and non-infiltrating neoplasm
- infiltrating accounts for 80% of adult brain tumors
- -> usually in cerebral hemispheres
- -> sx: seizures, headache, focal neurologic deficits
- -> morph: p53 and PDGF, higher grade is RB and p16/CDKNaA
90
Diffuse astrocytoma
Grade II
- poorly defined, gray, infiltrative tumor that invaders and distorts brain
- tumor is firm or soft and gelatinous with cystic degeneration
- glial cellularity and variable nuclear pleomorphism with GFAP astrocytic processes
91
Anaplastic astrocytoma
Grade III
| - densely cellular with nuclear pleomorphism with mitotic figures
92
Glioblastoma
Grade IV
- Some firm areas with white others soft and yellow from necrosis
- cystic degeneration and hemorrhage
- necrosis and vascular or endothelial cell proliferation
- pseudopalisading pattern
93
Pilocytic astrocytoma
Grade I
Age: children and young adults
Location: cerebellum or in floor and walls of third ventricle, optic nerves, cerebral hemispheres
Morph: cystic, if solid well circumscribed
- bipolar thin hairlike processes GFAP positive with fibrillary meshworks
- Rosenthal fibers and eosinophilic granular bodies
94
Oligodendroglioma
Stats: 5-15% of gliomas
Age: fourth and fifth decades
Sx: seizures
Morph: lesions in white matter
- well circumscribed, gelatinous, gray masses with cysts, focal hemorrhage, calcification
- sheets of regular cells with spherical nuclei containing finely granular chromatin surrounded by clear halo of cytoplasm
95
Ependymoma
Central canal of spinal cord
Age: first two decades of life occur near fourth ventricle
- adults: spinal cord, related to NF2
Morph: solid or papillary masses extending from floor of ventricle
- perivascular pseudorosettes --> tumor cells arranged around vessels with thin ependymal processes directed toward wall of vessel
- GFAP
Sx: hydrocephalus secondary to progressive obstruction of fourth ventricle
- can be disseminated by CSF
96
Choroid plexus papillomas
Age: children more common in lateral ventricle
- adult involve fourth ventricle
Sx: hydrocephalus from obstruction of ventricular system by tumor or overproduction of CSF
97
Colloid cyst of third ventricle
Non-neoplastic lesion occurring in young adults
- cyst attached to roof of third ventricle obstruct foramina of monro causing noncommunicating hydrocephalus
Sx: headache, positional; rapidly fatal
98
Ganglioglioma
Most common CNS tumor with mature appearing neurons --> admixed glial neoplasm
Morph: Commonly found in temporal lobe with cystic component
- irregularly clustered and has random neurites with binucleate forms
99
Medulloblastoma
Age: children mostly in midline, adults in lateral
Other: only in cerebellum
Sx: hydrocephalus, highly malignant, confusion with peripheral lesion related to ewing sarcoma, PNET
Morph: well circumscribed, gray, friable extending into cerebellar folia and leptomeninges
- extremely cellular with anaplastic cells, mitoses
- neuronal and glial phenotypes
- loss of 17p
- blue small cells
100
Germ cell tumors
Primary brain germ cell tumors along midline, pineal and suprasellar regions
- more common in Japanese
Age: young
Gender: males in pineal region
Sx: similar to counterparts in gonads, not usually metastasis --> alpha-fetoprotein and beta-HCG
101
Meningiomas
Age: adults
- benign tumors attached to dura from arachnoid
Morph: rounded masses with well defined bases that compress brain --> can be separated
- syncytial --> whorled clusters of cells in groups
- fibrobastic --> elongated cells and abundant collagen
- transitional --> syncytial and fibroblastic
- psammomatous --> psammomabodies
- secretory --> PAS positive intracytoplasmic droplets and intracellular lumens by EM
- microcystic --> loose spongy appearance
- Atypical (grade II), anaplastic (grade III)
Molecular: loss of chromosome 22, loss of NF2
Sx: vague nonlocalizing sx or focal findings
102
Most Common Metastasis
Lung, breast, skin, kidney, GI tract
| Morph: junction of gray and white matter with zone of edema surrounding
103
Limbic encephalitis
Subacute dementia with perivascular inflammatory cuffs, microglial nodules, neuronal loss, gliosis
104
Schwannoma
Benign tumors from neural crest derived cell --> part of NF2
Sx: locally compressed nerve or adjacent structures
Molecular: loss of NF2 merlin
Morph: well circumscribed masses attached to nerve but can be separated
- firm gray masses with cystic and xanthomatous change
- Antoni A showing high cellularity zones and nuclear free zones termed verocay bodies
- Antoni B less dense cells with microcyts and myxoid stroma
105
Neurofibroma
Discrete localized masses, nodules with hyperpigmentation
Morph: spindle cells with highly collagenized tumor
Molecular: NF1 inhibits RAS activity, loses NFI
106
Plexiform neurofibroma
Anywhere along nerve tumors, multiple
- cannot be separated from nerves
Morph: myxoid stroma with collagen bundles
Molecular: NF1 inhibits RAS activity, loses NFI
107
Malignant peripheral nerve sheath tumor
Locally invasive, frequent recurrences, metastases
- medium to large nerves
Morph: poorly defined tumor masses infiltrate along axis of parent nerve and adjacent soft tissues
- mitosis, necrosis, nuclear anaplasia common
108
Neurofibromatosis Type I
Inherited: Autosomal dominant disorder
- neurofibromas, gliomas of optic nerve, pigmented nodules of iris (lisch nodules), cutaneous hyperpigmented macules (cafe au lait spots)
Molecular: lack of NF1 activity, loses inhibition of RAS
109
Neurofibromatosis Type II
Inherited: autosomal dominant disorder
- range of tumors most commonly CN VIII schwannomas and multiple meningiomas with gliomas
Molecular: NF2 encodes merlin
110
Tuberous Sclerosis Complex
Inherited: autosomal dominant
- hamartomas and benign neoplasms involving brain and tissues
--> cortical tubers and subependymal nodules
--> renal angiomyolipomas, retinal glial hamartomas, pulmonary lymphangioleiomyomatosis, cardiac rhabdomyomas
- cyts found in liver, kidneyes, pancreas
Molecular: TSC1 encodes hamartin or TSC2 encodes tuberin
Morph: firm areas of cortex, haphazardly arranged neurons that lack organization
Sx: seizures
111
Von Hippel-Lindau disease
Inheritance: autosomal dominant disorder
- hemangioblastomas and cysts in pancreas, liver, kidneys, renal cell carcinoma and pheochromocytoma
Molecular: VHL is a tumor suppressor gene that regulates hypoxia induced factor I
Morph: hemangioblastomas highly vascularized neoplasms that occur with a large fluid-filled cyst
