CNS Neoplasms (pathoma)

Question 0

CSF findings in meningitis

Answer 0

• bacterial: high WBCs (neutrophils), increased protein, low glucose
• viral: High WBCs (lymphocytes), really increased protein, normal glucose
• fungal: High WBCs (lymphocytes), increased proteins, normal glucose

Question 1

Meningitis (common causes)

Answer 1

Leptomeninges infection

• GBS, E.Coli, Lysteria (infants)
• N. Meningitidis (kids - teens)
• H.flu (non-vac kids)
• coxsackie (most common viral men.)
• fungi (immunocomp)

Question 2

Watershed infarcts (causes, susceptibility)

Answer 2

• watershed zones
• result of moderate ischemia/global hypoperfusion
• purkinje fibers of pyramidal cells of hippocampus, and pyramidal neurons of cortex (layers 4,5)

Question 3

Brains response to ischemia (4 steps)

Answer 3

• day 1: neurons die
• week 1: neutrophils/microglia infiltrate
• month 1: brain Eq of granulation tissue
• post month: cyst formation in area of gliosis

Question 4

Red vs. Pale infarcts

Answer 4

• pale is an ischemia caused by thrombus rupture forming an unlyseable clot
• red infarct (hemorrhagic) is caused by a transient clot that forms, the neurons die and blood fills up empty space

Question 5

Xanthochromiatic

Answer 5

• occult blood in CSF
• biliruben breakdown results in yellow colored CSF
• can confirm subarachnoid bleed

Question 6

CNS neoplasms basics

Answer 6

• infrarentorial in kids
• supratentorial in adults
• if they are a primary tumor they won’t generally spread
• mets are typically associated with MCA distribution

Question 7

GBM

Answer 7

• Most common CNS malignancy in adults
• typically supratentorial, butterfly transcallosal dist.
• palisading necrosis and/or endothelial proliferation
• contain GFAP

Question 8

Meningioma

Answer 8

• typically adult females
• adhering to dura
• compress, don’t invade
• whirled cell arrangement, when calcified -> psamomma bodies

Question 9

Schwannoma

Answer 9

• cerebellopontine angle (which is probably why it causes acoustic neuromas)
• S100 positive
• bilateral vestibular Schwannomas (NF-2)

Question 10

Oligodendroglioma

Answer 10

• calcified white matter in the frontal lobe
  ~ associated with frontal love seizures
• fried egg appearance on biopsy

Question 11

Pilocytic astrocytoma

Answer 11

• benign astrocytic cystic lesion with mural nodule
• more common in kids
• infrarentorial
• Rosenthal fibers

Question 12

Ependymoma

Answer 12

• more common in kids: infrarentorial
• generally in fourth ventricle -> progress to hydrocephalus
• perifasciular pseudorosettes

Question 13

Meduloblastoma

Answer 13

• neuroectodermal origin
• HW rosettes
• poor prognosis
• common sightings of drop down mets

Question 14

Craniophryngioma

Answer 14

• in kids -> supratentorial (breaks rule)
• epi remnant of rathkes pouch (ant pit origin)
• alt cause for CN II compression
• benign but tends to be recurrent following resection