Neurosurgery: Neoplastic Disease Flashcards
Approach to:
Inferior frontal lobe and parasellar region
Bicoronal incision with unilateral/bilateral subfrontal approach
Pterional approach
Approach to:
Sellar region
Transsphenoidal
Bicoronal incision with unilateral/bilateral subfrontal approach
Pterional approach
Approach to:
Frontal lobe
Frontal craniotomy (linear, curved, or horseshoe incision)
Approach to:
Anterior temporal lobe
Temporal craniotomy (linear incision)
Approach to:
Posterior temporal lobe
Temporal craniotomy (linear, reverse question mark, or Isle of Mann incision)
Approach to:
Parietal lobe
Parietal craniotomy (linear or horseshoe incision)
Approach to:
Occipital lobe
Occipital craniotomy (linear or horseshoe incision)
Approach to:
Trigone of lateral ventricle
Appropriate craniotomy for superior parietal, middle temporal gyrus, lateral tempero-occipital, or transoccipital approach (linear or horseshoe incision)
Approach to:
Anterior third ventricle
Frontal parasagittal craniotomy and interhemispheric/transcallosal or transcortical approach
Interforniceal or transchoroidal approach once within
Approach to:
Posterior third ventricle/pineal region
Suboccipital transtentorial
Supracerebellar infratentorial approach
Interhemispheric transcallosal (splenium) approach
Transcortical parietal approach (rarely used)
Approach to:
Midline posterior fossa/fourth ventricle
Suboccipital craniotomy (linear incision)
Approach to:
Lateral posterior fossa/CPA
Retrosigmoid craniotomy (linear incision)
Approach to:
Upper clivus
Subtemporal approach and anterior petrosectomy (linear or horseshoe approach)
Approach to:
Middle and lower clivus
Combined retrosigmoid posterior temporal craniotomy and posterior petrosectomy (curvilinear incision)
What is located two finger breadths above the zygomatic arch and one thumb’s breadth behind the frontal process of zygomatic bone?
Pterion
What landmark does the asterion represent?
Asterion is on skull over the lower half of the transverse/sigmoid sinus junction
Asterion: junction of lamboid, occipitomastoid, and parietomastoid sutures
What lays at the junction of the lamboid and sagittal suture?
Lambda
What lays at the junction of the coronal and sagittal sutures?
Bregma
Where is the inion located?
At indentation below external occipital protuberance
How can you roughly estimate the location of the Sylvian fissure? (Stepwise approach)
1) Draw a line connecting the nasion and inion, find the 75% point on the line (closer to inion)
2) Mark frontozygomatic point
3) Connect the two points and the Sylvian fissure travels along this axis
- Pterion is located ~3cm behind the frontozygmatic point
How can you approximate location of Rolandic fissure (aka central sulcus)? (Stepwise approach)
1) Find upper Rolandic point (2cm posterior from 50% point on a line connecting nasion and inion)
2) Lower Rolandic point is at junction of line from upper rolandic to midzygomatic arch and sylvian fissure line (Lower Rolandic point is 2.5 cm behind pterion along Sylvian line)
How far behind the coronal suture is the motor stip usually located?
4 to 5.4 cm
What is a rough estimate of the location of the Angular gyrus (which is part of Wernicke’s area)?
Just above pinna of ear
Astrocytic tumors may be graded II, III, or IV. What are these specific types typically called?
Grade II: Low grade astrocytoma
Grade III: Anaplastic astrocytoma
Grade IV: GBM
What is standard treatment for astrocytomas?
Surgical resection (partial or complete) followed by external beam radiation and temozolomide
What are common locations for pilocytic astrocytomas?
Cerebellar
Optic glioma type
Hypothalamic hemisphere
Optic gliomas are common in what genetic condition?
What type of tumors are these typically?
NF1
Pilocytic astrocytomas
What is tx of choice for cerebellar pilocytic astrocytomas?
Surgical resection
They often have an enhancing mural nodule; if the mural nodule (contrast-enhancing) is removed the cyst wall doesn’t need to be completely taken
What is treatment of choice for pilocytic astrocytomas of optic nerve or hypothalamus?
If sparing resection can be completed then removal but if resection risky then biopsy with chemo and radiation
How do oligodendrogliomas often present?
Seizures and/or hemorrhage
What is unique about oligodendrogliomas on CTH?
They may have associated calcifcation
What chromosomal loss is associated with better response to treatment in oligodendroglioma?
Loss of 1p and 19q
Where do ependymomas often arise from?
Floor of 4th ventricle
What is preferred treatment of ependymomas?
Should you aim for full resection?
Surgical resection
Maximal resection is associated with improved survival
Given proximity to CSF space. What adjunctive test should be done in patients with ependymoma?
LP (cytology) and spinal MRI to look for subarachnoid mets
In what age group do choroid plexus papillomas often present? How do they present? What is mgmt?
<2 yo
HCP
Resection followed by chemo (radiation if carcinoma)
What are the different types of pediatric brainstem glioma (3)?
Tectal glioma
Focal tegmental mesencephalic
Diffuse pontine glioma
What is general treatment of choice for each of following types of pediatric brainstem glioma:
Tectal giioma
Focal tegmental mesencephalic
Diffuse pontine glioma
Tectal glioma: CSF diversion due to HCP risk
Focal tegmental mesencephalic: Resection, chemo/rad
Diffuse pontine glioma: radiation, experimental chemo, palliative
Angiocentric glioma
Rare, slow-growing low-grade glial often in kids/young adults with seizures. Resection often curative
Choroid glioma third ventricle
Rare low-grade glial often with HCP/chiasm compression/hypothalamic dysfunction often cured by resection
Astroblastoma
Rare low-grade glial tumor often in kids/young adults and surgically resected with adjuvant chemo/rad
What is dysplastic cerebellar gangliocytoma also known as?
What syndrome is it associated with?
How does it present and how is it managed?
Lhermitte-Duclos Disease
Cowden Syndrome (multiple hamartomas)
Inc’d ICP/HCP, cerebellar signs, slow progression
Resection
Desmoplastic infantile ganglioglioma presents in what age group?
How does it present?
What is it’s survivability?
What is optimum treatment?
<2 yo (peak 3-6 months)
Bulging fontanelles, inc’d head size, paresis, seizures
>75% survive at 15 years
Resection curative; chemo if anaplasia
In what age group do dysembryonic neuroepithelial tumors (DNETs) present?
Are they fast or slow growing lesions?
What will they commonly present with?
What is treatment?
Children and young adults (<20 yo)
Slow growing, benign
Epilepsy
Surgical resection +/- epileptogenic foci
In what age group do gangliogliomas/gangliocytomas present?
What is typical presentation?
What is mgmt?
<30 yo (peak 11 yo)
Epilepsy; slow growing, benign lesions
Resection +/- chemo if anaplastic
In what location do central neurocytomas often present?
What is presentation?
What is survivability?
What is mgmt?
Intraventricular
ICP rise and HCP; seizures
5 yr survival > 80%; benign and slow-growing
Resection; SRS/chemo for recurrence
Central liponeurocytoma often presents in what age group and what location?
What is appropriate management?
Adults; posterior fossa
Resection; possible radiation to prevent recurrence
How common is papillary glioneuronal tumor?
What is presentation?
What is mgmt?
Rare adult tumor
Seizures; slow-growing, benign tumors
Resection
How do rosette-forming glioneuronal tumors of the 4th ventricle often present?
What is mgmt?
Rising ICP and HCP with ataxia
(In young adults often)
Resection usually curative
Paraganglioma at the carotid bifurcation is known as …
Carotid body tumor
Paraganglioma at the superior vagal ganglion is known as …
Glomus jugulare tumor
Paraganglioma at the auricular branch of vagus is known as …
Glomus tympanicum
Paraganglioma at the inferior vagal ganglion is known as …
Glomus intravagale
What are the 3 types pf astrocytes?
Fibrillary - in WM, PTAH, silver, GFAP pos.
Protoplasmic - in GM, larger nucleous, less citoplasm
gemistocytic - swollen, active, near injury
Circumscribed astrocytic tumors
low gr, good prognosis, frequently cystic
1. Juvenile pilocytic astr.
2. pleomphic xantoastrocytoma
3. Subependimal gian cell astr.
General attributes of pilocystic astrocytomas
2nd most common ped. brain tumor
location: cerebellum, brainstem, optic pathway!, infundibulum
age: 10 yrs
morphology: red-tan nodule, 60% cystic, nodule enhance, 10% contain calcium
survival: 5y: 86-100% 20y 70%
Histology of pilocystic astrocytomas
Growth pattern
Predominantly solid / circumscribed; often limited peripheral infiltration
Frequent extension into subarachnoid space
Biphasic appearance
Compact fibrillar portions: elongated nuclei, bipolar piloid processes, Rosenthal fibers
Loose microcystic portions: round to oval nuclei, cobweb-like processes, eosinophilic granular bodies
What is Rosenthal fiber? What pathology?
A Rosenthal fiber is a thick, elongated, worm-like or “corkscrew” eosinophilic (pink) bundle that is found on staining of brain tissue in the presence of long-standing gliosis, occasional tumors, and some metabolic disorders.
Pilocytic astr.
Pleomorphic xanthoastrocytoma general attributes
low grade astrocytoma
age: 7-25
Majority of tumors occur supratentorially, most commonly in temporal lobes (seizures!)
Often superficially located with involvement of the overlying leptomeninges
Many patients present with long history of epileptic seizures
occasionly transform to GBM
Pleomorphic xanthoastrocytoma histology
bizarre pleomorphic cells
xanthomatous fat cells
multinucleoted cells
Pleomorphic appereance histology
Subependymal giant cell astrocytoma (SEGA)
Benign, slowly growing tumor typically arising in wall of lateral ventricles and composed of large ganglioid astrocytes
Usually associated with tuberous sclerosis
Near foramen Monroe –> hydrocephalus!
Tuberous sclerosis complex
seizures, retardation, sebaceous adenomas
TSC1 Ch9 = hamartin
TSC2 Ch16= tuberin
subependymal calcification
Diffuse gliomas
fibrillary (most frequent)
protoplasmic
gemistocytic (worst prognosis
mixed
Grade: anaplasia, cellualrity, nucl. plomorffism, endothel. prolif., necrosis, pseudopalisading
- Mutations in IDH1/2, ATRX, TERT, and TP53 and co-deletion
of 1p/19q correlate better with tumor biological and clinical
behavior than do stratifications based only on histological
features
Adult type diffuse gliomas astrocytoma, IDH mutant
IDH1 / IDH2 mutated,diffusely infiltrating glioma, most often with concurrent TP53 or ATRX mutations and without 1p / 19q codeletion
Can be graded CNS WHO grade 2, 3 or 4
IDH1 codon 132 or IDH2 codon 172 mutated, diffusely infiltrating glioma without 1p / 19q codeletion and usually with TP53 or ATRX mutations
In the absence of 1p / 19q codeletion, a component that morphologically resembles oligodendroglioma is compatible with this diagnosis
Can be designated CNS WHO grade 2, 3 or 4 depending on presence of mitotic activity, nuclear atypia, pleomorphism, necrosis, microvascular proliferation or CDKN2A / CDKN2B homozygous deletion
Significant proliferative activity is consistent with a CNS WHO grade 3 diagnosis
Presence of either necrosis, microvascular proliferation or CDKN2A / CDKN2B homozygous deletion is consistent with a CNS WHO grade 4 diagnosis
Infiltrating gliomas histology
Typical histologic features of infiltrating gliomas. In diffuse astrocytomas (a), cellularity is increased due to infiltrating neoplastic astrocytes with irregular, hyperchromatic nuclei and scant associated cytoplasm. Immunohistochemistry for IDH1 R132H mutant protein (A, inset) can be helpful when infiltrating cells are sparse or rare. b Anaplastic astrocytoma is distinguished by mitotic activity (black arrow). Note the infiltrating tumor cells around a non-neoplastic neuron (white arrowhead). c Palisading necrosis (left) and endothelial proliferation (upper right) are histologic features of glioblastoma, though neither feature is absolutely specific.
Gemiostocytic astrocytoma
worst prognosis
Gemistocytes are polygonal
cells with peripherally
displaced nuclei and glassy
cytoplasm, as well as coarse
processes. Despite the tumor’s
aggressive behavior, mitoses
are usually hard to find
Genetic alteration in gliomas
Oligodendroglioma, (IDH mutant, 1p / 19q codeleted)
CNS WHO 2021 definition: diffusely infiltrating glioma with IDH1 or IDH2 mutation and codeletion of chromosome arms 1p and 19q (CNS WHO grade 2 or 3)
Essential features
Diffusely infiltrating glial neoplasm with IDH1 or IDH2 mutation and 1p / 19q whole arm codeletion (both features are required for diagnosis)
Morphology resembles nonneoplastic oligodendrocytes with round monotonous nuclei and perinuclear halos
Chicken wire vasculature, microcalcifications and microcysts are characteristic
Median overall survival: 11.6 years; 10 year overall survival rate: 51 - 63%
Unfavorable features:
Contrast enhancement on MRI
CNS WHO grade 3 histology
CDKN2A / CDKN2B homozygous deletion
Local recurrence and malignant transformation are common
Classic oligodendroglioma features
perinuclear halo = fried egg (= citoplasma retractio –> artefitial! not in frozen sample)
present with seizure
higher frequency of hemorrhage
have calcification
Greenberg:
● slow growing tumor that frequently presents with seizures
● occur primarily in adults, predilection for the frontal lobes (F>T)
● by definition: a diffusely infiltrating glioma with codeletion of BOTH chromosome arms 1p AND
19q, AND mutation of IDH1 OR IDH2
● histology: classic features of “fried egg” cytoplasm (on permanent pathology) & “chicken wire” vasculature are unreliable. Calcifications are common
● recommended treatment: as for WHO grade II astrocytic tumors
Gliosarcoma
Rare, classic variant of glioblastoma (GBM), WHO grade 4
Biphasic glial and mesenchymal differentiation
2% of GBM, 40-60y, temporal lobe, dural invasion
GBM component GFAP stains
intra-extracranial metastasis
Sarcoma: from vascular structures
Median overall survival with treatment (both primary and secondary gliosarcoma): 17.5 months (J Neurooncol 2015;125:401)
Median overall survival with treatment: 24.7 months
Optic glioma
Relatively rare
Slow growing tumor within orbital segment of optic nerve
Usually ages 0 - 9 years with symptoms of minimal exophthalmos, optic nerve atrophy or papilledema
Associated with neurofibromatosis type 1
Necrosis in GBM
GBM favorable factors
- KPS >80
- younger age
- IDH1 mut
- MGMT promoter methylation (unmethlyated medisan OS 12.2 m; methy.: median OS 18.2m)
worst: IDH wild, MGMT unmeth., biopsy, 50y older
RANO criteria
RANO criteria is a set of guidelines used to assess treatment response in patients with glioblastoma, a type of brain cancer. The criteria include four categories: complete response, partial response, stable disease, and progressive disease. These categories are based on changes in tumor size, enhancement, and clinical status.
MR spectroscopy
ChoCrNALaLi
CHOCNALALI
lactate: endproduct of anaerob glycolysis (hypoxia)
N-acetyl-aspartate: neuronal marker, tallest peak (csökkent in ALL abnormalities)
cholin: marker of membrane synthesis (stroke is low)
GLIOMAS:
higher lactate, lipid, cholin, lower NAA (higher the choloin, higher the grade!)
ABCESS: low NAA, Cr, CHo; atypical paeks (from baci –> succinate, acetate…), lavetate can be elevated
Glioma MRS
csökk NAA; növ: lactate, lipid, cholin
Ependymomas (of post. fossa) key concepts
● usually benign tumors, often fibrillary with epithelial appearance. Perivascular pseudorosettes or
ependymal rosettes may be seen
● most often occur in the floor of the 4th ventricle, presenting with hydrocephalus (increased ICP)
and cranial nerve VI & VII palsies
● evaluation: includes imaging the entire neuraxis (MRI with and without enhancement: cervical,
thoracic, lumbar & brain) because of potential for seeding through CSF
● worse prognosis the younger the patient (especially age < 24 months)
● treatment: the best outcomes are associated with gross total removal (no enhancing tumor on
post-op MRI) followed by XRT. XRT may be withheld for age < 3 years due to side effects
● do LP ≈ 2 weeks post-op to send ≈ 10 cc of CSF for cytology for prognostication
Specific ependymoma types
- supratentorial
- supratentorial ZFTA-fusion + (ZFTA fused w/ RELA)
- supratentorial YAP1 fusion +
- posterior fossa
- posterior fossa Group A
- posterior fossa Group B
- spinal ependymoma
- spinal ependymoma MYCN amplified
- myxopapillary ependymoma
- subependymoma
Ependymoma types 2021 WHO
Overview of key characteristics and diagnostic criteria of the distinct ependymoma tumor types as proposed by the 2021 WHO Classification of CNS tumors. Range of age (in years) at onset of disease is indicated in black, the median age of onset is highlighted with a red triangle. PFS and OS are rated on a scale of green (very low progression rate and good OS), orange (intermediate PFS and OS) to red (high progression rate and dismal survival prognosis). For SE, we highlighted that tumors with supratentorial or spinal location have a low progression rate. In contrast, SE of the PF have a higher tendency to progress. Typical molecular features described to date are indicated for each tumor type. Obligatory criteria for the diagnosis of all ependymoma types are morphological and immunohistological features of ependymoma. Additional obligatory criteria are listed for each tumor type. Also, the 2021 WHO Classification provides desirable criteria for the diagnosis of each tumor type that can support the diagnosis. CNP, copy number profile; MPE, myxopapillary ependymoma; NEC, not elsewhere classified; NOS, not otherwise specified; OS, overall survival; PF, posterior fossa ependymoma; PF-A, group A posterior fossa ependymoma; PF-B, group B posterior fossa ependymoma; PFS, progression free survival; SE, subependymoma; SP-EPN, spinal ependymoma; SP-MYCN, MYCN-amplified spinal ependymoma; ST, supratentorial ependymoma; ST-YAP1, YAP1-fusion positive ependymoma; ST-ZFTA, ZFTA-fusion positive ependymoma
Ependymoma mutations and locations
Ependymal rosettes
true rosettes
perivascular rosettes
Choroid plexus papilloma
Rare intracranial tumor arising in the ventricle, mainly occurring in children
3 histological grades (WHO grade 1, 2, 3): choroid plexus papilloma (CPP), atypical choroid plexus papilloma (aCPP), choroid plexus carcinoma (CPC)
Histological classification is based on architecture (preservation of papillary pattern), cellular density, cytology (nuclear pleomorphism), proliferation (mitoses) and necrosis / brain invasion
Diagnostically, transthyretin (TTR), KIR7.1, cytokeratin and Ki67 immunohistochemistry are most helpful
Based on methylation profiling, these tumors are now categorized in to 3 subtypes
In line with other CNS tumors, integrated phenotype genotype diagnosis is preferred, which will guide appropriate management
Choroid plexus papilloma histology
Choroid plexus papilloma are benign tumors with preserved papillary or finger-like architecture, with fibrovascular cores, lined by single layer of cuboidal to columnar epithelium, almost resembling nonneoplastic choroid plexus but with mild cellular atypia and without significant mitotic activity.
Choroid plexus carcinoma
mostly children
lat ventricles
40% @ LiFraumeni sy –> TP53 mutation
