ABPath Neuropathology

Question 1

Which histologic feature is MOST characteristic of glioblastoma multiforme (GBM)?

Accepted Answer

Pseudopalisading necrosis

Answer

Pseudopalisading necrosis, where tumor cells line up around areas of necrosis, is the hallmark histologic feature of GBM (WHO Grade IV astrocytoma).

Question 2

A 10-year-old presents with a cerebellar mass; biopsy shows a biphasic pattern with compact Rosenthal fiber-rich areas and loose microcystic areas. What is the most likely diagnosis?

Accepted Answer

Pilocytic astrocytoma

Answer

Pilocytic astrocytoma is a WHO Grade I tumor with a classic biphasic pattern of compact bipolar cells with Rosenthal fibers and loose areas with eosinophilic granular bodies.

Question 3

Which immunohistochemical marker is MOST useful for distinguishing meningioma from other CNS tumors?

Accepted Answer

EMA

Answer

EMA (epithelial membrane antigen) is characteristically expressed in meningiomas and helps differentiate them from glial tumors that express GFAP.

Question 4

Lewy bodies, the pathologic hallmark of Parkinson disease, are composed primarily of which protein?

Accepted Answer

Alpha-synuclein

Answer

Lewy bodies are intracytoplasmic inclusions composed primarily of aggregated alpha-synuclein protein, also seen in Lewy body dementia.

Question 5

Which variant of medulloblastoma carries the BEST prognosis according to WHO 2021 classification?

Accepted Answer

WNT-activated

Answer

WNT-activated medulloblastoma has a >95% 5-year survival rate, making it the most favorable molecular subgroup of medulloblastoma.

American Board of Pathology (ABPath) Practice Test

American Board of Pathology (ABPath) Practice Test

ABPath Neuropathology