Nervous System Neoplasms

Question 1

Tumor Grading Features

Grade I, Grade II (2) Grade III (2) Grade IV (3)

Answer 1

Benign

Infiltrative, atypia

Anaplasia, Mitoses

Microvascular infiltration, necrosis, fatal

Question 2

Pilocytic Astrocytoma

Grade, Locations (2) Genetics, Morphology (5)

Answer 2

Grade I

Cerebrum white matter
Cerebellum

NF1 Defect causing Neurofibromin LOF
(neurofibromatosis)

Cystic with mural nodule
Biphasic pattern
Hairlike cells with bipolar processes
Rosenthal fibers
Eosinophilic granular bodies

Question 3

Glioblastoma

Grade, Location, Primary (3) vs Secondary (2) Morphology (4) Histology (3)

Answer 3

Grade IV

All throughout brain

Primary:
No precursor
EGFR and PTEN mutations

Secondary:
IDH1/IDH2 mutation
Better prognosis

GFAP (+)
Contrast ring enhancing lesion
Hypodense central necrosis
Black thrombosed veins

Serpentine Necrosis
Pseudo-Palisading
Vascular/Endothelial proliferation

Question 4

Oligodendroglioma

Location, Morphology, Histology (2) Genetics (3)

Answer 4

Cerebral hemispheres white matter

Cortex Calcification

Perinuclear halos (fried egg nucleus)
Anastomosing capillaries (chicken wire)

IDH1
IDH2
1p19q loss
(favorable outcomes)

Question 5

Ependymoma

Ages, Grade, Locations (2), Morphology (3)

Answer 5

First two decades of life

Grade III

4th ventricle (enhancing)
Supratentorial

Ependymal Rosettes
Tubular structures with central canal
Fibrillary background

Question 6

Ventricular Tumors
Choroid Plexus and Colloid Cyst
Age group, Location, Complication

Answer 6

Choroid Plexus Papilloma
Seen in Children
Lateral Ventricles
Obstructive Hydrocephalus

Colloid Cyst
Seen in young adults
3rd Ventricle
Non-communicating Hydrocephalus 
(via Foramen of Monro obstruction)

Question 7

Medulloblastoma

Grade, Age, Locations (2) Genetics (2) Morphology (3) Treatment, Spread Pattern

Answer 7

Grade IV

Children

Cerebellum
Midline cerebrum

*worst prognosis
MYC amplification
I17Q mutation

Sheets of anaplastic cells
Abundant mitoses
Homer-Wright Rosettes

Extremely sensitive to radiation therapy

Drop Metastases (CSF to cauda equina)

Question 8

Atypical Teratoid/Rhabdoid Tumor

Grade, Age, Locations (2) Morphology (3) Genetics (2) Prognosis

Answer 8

Grade IV

Children under 2 years

Posterior Fossa
Supratentorial

EMA (+)
Vimentin (+)
Rhabdoid cells

Chr 22 hSNF5/INI1

Highly aggressive, fatal within a year

Question 9

Primary CNS Lymphoma
Disease Associations (2) Origin, Morphology, Staining

Answer 9

HIV
EBV

CD20+ B cells

Cells accumulate around vessels

Hooping: cells separated by reticulin and silver stain

Question 10

Germ Cell Tumors

Locations (3)

Answer 10

Midline Cerebrum
Pineal gland
Suprasellar

Question 11

Pineal Tumors

Examples (3) with Descriptions (1/2/3)

Answer 11

Germinoma: most common

Pineocytoma: low grade, in adults

Pineoblastoma: high grade, in kids, RB gene

Question 12

Meningioma

Location, Genetics (2) Histology (2) Complication

Answer 12

Dura mater

NF2
TRAF7

Whorled cluster of monotonous cells
Psammoma bodies

Present progesterone receptor, danger of preterm pregnancy

Question 13

Metastatic Brain Tumors
Origin Sites (4) Location, Morphology, Complications (3)

Answer 13

Lung
Breast
Melanoma
Choriocarcinoma

Meninges are common site

Cribiform glands with necrosis

Melanoma and Choriocarcinoma metastases tend to hemorrhage
Spinal cord compression
Carcinomatosis

Question 14

Subacute Cerebellar Degeneration
Etiology, Associated Carcinomas (3)
Treatment (2)

Answer 14

*Paraneoplastic syndrome

PCA-1 antibody

Ovarian
Breast
Uterine

Immunotherapy to remove antibodies
Removal of tumor

Question 15

Limbic Encephalitis
Etiologies with Associated Cancers (3)
Treatment (2)

Answer 15

*Paraneoplastic syndrome

ANNA-1 antibody: Small cell carcinoma of lung

NMDA receptor: ovarian teratomas

VGKC-Complex Antibody causes peripheral neuropathy

Immunotherapy to remove antibodies
Removal of tumor

Question 16

Cowden Syndrome

Gene and Associated Tumor

Answer 16

PTEN mutation

Dysplastic gangliocytoma

Question 17

Tuberous Sclerosis Complex

Genes (2), Tumors (6) Symptoms (3)

Answer 17

TSC1
TSC2

Cortical Hamartomas
Subependymal nodules
Subependymal giant cell astrocytomas

Retinal Hamartomas
Renal Angiomyolipomas
Cardiac Rhabomyomas

Seizures
Autism
Mental Retardation

Question 18

Von Hippel Lindau Disease

Pathogenesis (3) Clinical Features (5)

Answer 18

VHL mutation downregulates HIF-1 which incrreases VEGF

Polycythemia
Hemangioblastomas of Cerebellum and Retina
Liver Cysts
Renal Cell carcinoma
Pheochromocytoma

Question 19

Li-Fraumeni Syndrome

Gene and Associated Tumor

Answer 19

TP53

Medulloblastomas

Question 20

Turcot Syndrome

Gene and Associated Tumors (2)

Answer 20

APC gene

Medulloblastoma
Glioblastoma

Question 21

Gorlin Syndrome

Gene and Associated Tumor

Answer 21

PTCH gene

Medulloblastoma

Question 22

Neurofibromatosis Type 2

Gene, Tumors (4) Schwannoma Morphology (2)

Answer 22

NF2 loss (MERLIN)

Cerebellar pontine angle (schwannoma)
Acoustic neuroma (schwannoma)
Meningiomas
Ependymomas

Antoni A: Verocay bodies (palisading nuclei)
Antoni B: hypocellular, myxoid ECM

Question 23

Neurofibromatosis Type 1

Gene, Tumors (4), Non-Tumor Presentations (2)

Answer 23

NF1

Plexiform Neurofibromas
Diffuse Neurofibromas (subcutaneous)
Localizing cutaneous neurofibromas
Optic Nerve gliomas

Lisch nodules on iris
Cafe au lait spots (hyperpigmented near mouth)

Question 24

Malignant Peripheral Neural Sheath Tumor

Grade, Etiology, Morphology, Subtype with Description

Answer 24

High grade tumors

Malignant transofrmation of plexiform neurofibromas in NF1

Marbleized tumors
Divergent differentiation
Poorly differentiated

Triton Tumor: Rhabdomyoblastic morphology