ABPath Neuropathology 2

Question 1

A perivascular pseudorosette pattern on histology is MOST characteristic of which brain tumor?

Accepted Answer

Ependymoma

Answer

Ependymomas characteristically display perivascular pseudorosettes (tumor cell processes tapering toward vessels) and true ependymal rosettes.

Question 2

Which genetic alteration is PATHOGNOMONIC for oligodendroglioma per WHO 2021 CNS classification?

Accepted Answer

IDH mutation + 1p/19q codeletion

Answer

The combination of IDH mutation and 1p/19q codeletion is required for the diagnosis of oligodendroglioma by WHO 2021 molecular criteria.

Question 3

Spongiform encephalopathy with PrP-positive plaques and rapid progressive dementia is MOST consistent with which condition?

Accepted Answer

Creutzfeldt-Jakob disease

Answer

Creutzfeldt-Jakob disease (CJD) is a prion disease characterized by spongiform change, astrogliosis, neuronal loss, and PrP-positive amyloid plaques.

Question 4

Which stain is BEST used to highlight amyloid plaques in Alzheimer disease on formalin-fixed paraffin-embedded brain sections?

Accepted Answer

Congo red

Answer

Congo red stain reveals amyloid deposits as red-orange material with apple-green birefringence under polarized light, used to identify amyloid plaques.

Question 5

A midline H3 K27M-mutant diffuse glioma in a pediatric patient is classified as WHO Grade how?

Accepted Answer

Grade IV

Answer

H3 K27-altered diffuse midline glioma is automatically classified as WHO Grade IV regardless of histologic appearance, due to its uniformly poor prognosis.

American Board of Pathology (ABPath) Practice Test

American Board of Pathology (ABPath) Practice Test

ABPath Neuropathology 2