CNS - Tumors

Question 1

This tumor presents in middle aged/older Pt. It is a lesion of the white matter that does not cross the corpus callosum. Slides show a vast network of blood vessels forming a wire-like appearance behind a central nucleus and perinuclear clearing, giving it a “fried egg” appearance. What tumor is this and what is the prognosis? What genetic elements cause these?

Answer 1

Oligodendroglioma
–From oligodendrocytes, not a true glioma (will NOT be GFAP+)

Prognosis is decent (5-10 years) b/c these are slow-growing, can be removed by tend to reoccur

Memory: “egg”liodendrogliomas

Genetics: IDH1 and IDH2 mutations (isocitrate dehydrogenase)
–Co-deletions of 1p and 19q are seen in 80% of cases –> this makes it HIGHLY SUSCEPTIBLE to radiation

Question 2

These neoplasms occur in the 4th ventricle of children and the lateral ventricle or spinal canal of adults b/c they grow inside of CSF. These distinctly show cells that grow/organize around a central lumen or blood vessel, which is called a _____. What are they and what can they cause?

Answer 2

Ependymomas

Rosettes (around lumen) or psuedo-rosettes (around vessel)

Can cause hydrocephalus

Memory: you give roses to your momma

Question 3

This neoplasm is attached to the dura and occurs more in adulthood, men more often than women. Buzzword is cellular whorls + psammoma bodies. What is this and how is the prognosis? What are the gene mutations that predispose a person to these neoplasms?

Answer 3

Meningioma - derived from meningothelial cells of arachnoid mater

-Very good; resection is curative because this lesion does NOT invade

NF2 mutations on Chrom 22q12 (codes merlin protein)

–Also sometimes TRAF7 (TNF-receptor factor 7)

Question 4

This poorly differentiated tumor develops mostly in children, usually in the cerebellum. Histo shows small blue round cells that can break off into CSF and metastasize to the cauda equina (drop metastasis). What is this and what are the subtypes? What is the prognosis?

Answer 4

Medulloblastoma

Types: WNT, SHH, and i17q MYC mutations

Prognosis: Great if treated as they are very amendable to radiation

EXCEPTION: tumors w/ the i17q MYC mutation have very poor prognosis always

Question 5

This neoplasm presents in a Pt that has hearing loss and tinnitus. It is an acoustic neuroma that is found on the cerebellopontine angle on CN8. It also shows Verocay bodies and S-100 expression. What is it and what are cell arrangments? What genetic predisposition is there?

Answer 5

Schwannoma

• Pathognomonic: Verocay Bodies and expression of S-100
• Antoni A regions (hypercellularity) + Antoni B regions (hypocellularity)

NF2 = bilateral acoustic neuroma predisposition

Question 6

This neoplasm is a remnant of Rathke’s Pouch usually seen in kids and young adults. It causes bitemporal hemianopsia because it is near the optic chiasm.

Answer 6

Craniopharyngioma

Question 7

What does NF1 mutation present as?

Answer 7

Nerufibromin protein mutation

Cafe-au-lait spots + hamartomas of the eyes (Lisch nodules)

Question 8

What are the characteristics of VHL (Von Hippel Lindau)?

Answer 8

A combination of: Cysts of liver and pancreas + pheochromocytomas + hemangioblastomas of cerebellum / retina

Question 9

What does Tuberous sclerosis present as?

Answer 9

Seizures, mental retardation, multiple angiofibromas, brain tubers, and Ash-leaft skin lesions

Question 10

Nevus flammeus (“port wine stain” - a facial cavernous angioma) in combination with choroidal hemangioma and calcification is what syndrome?

Answer 10

Sturge-Weber

Memory: sturgeon was a wine drinking flaming bitch

Question 11

This is a benign tumor of children and adults. It has characteristic neural nodules seen on MRI and contain Rosenthal fibers (elongated eosinophilic structures w/in astrocytic processes that contain αβ-crystallin and hsp27). What is it, what grade is it, and where does it occur? What is the prognosis?

Answer 11

Pilocytic Astrocytoma

-Grade I/IV

In the posterior fossa

Prognosis is good w/ surgical resection

Question 12

This neoplasm is the most common CNS tumor. It shows ring enhancing lesions and rows of anaplastic cells lined up around a region of central necrosis (“pseudopalasading necrosis”). Has glomeruloid vascularization and occurs in white matter, in which it crosses the corpus callosum and causes a “butterfly” lesion. What is this and what is the grade/prognosis?

Answer 12

Glioblastoma Multiforme (GBM)

Grade IV/IV

Poor prognosis: death w/in 1 year, difficult to resect, and unresponsive to chemo