Brain Tumor Quick Quiz

Question 1

Pilocytic astrocytoma

Answer 1

MC benign in children, affecting astrocytes which form BBB

• arises in cerebellum
• cystic lesion w mural nodule
• rosenthal fibers (thick eosinophilic processes of astrocytes)
• GFAP positive

Question 2

Glioblastoma Multiforme

Answer 2

• MC malignant, adult
• usually arises in cerebral hemisphere, crosses corpus callosum
• pseudopalisading: areas of necrosis surrounde by tumor cells
• GFAP positive

Question 3

Oligodendroglioma

Answer 3

• Malignant tumor of oligodendrocytes
• calcified tumor in white matter, sually involving frontal lobe. may present w seizures
• fried egg appearance of cells on biopsy

Question 4

Ependymoma

Answer 4

• Malignant tumor in children
• of ependymal cells; line ventricle and make CSF
• tumor usually arises in 4th ventricle, may cause hydrocephalus
• perivascular pseudorosettes

Question 5

Medulloblastoma

Answer 5

Malignant tumor in children

• derived from granular cells of cerebellum (neurectoderm)
• Homer-wright rosettes: small round blue cells surround pink neurotic processes
• poor prognosis, tumor spreads to CSF via 4th ventricle
• “drop metastasis” to cauda equina

Question 6

Meningioma

Answer 6

MC benign in adult

• tumor of arachnoid cells
• more commonly seen in women (tumor expresses E receptor)
• present w seizures, tumor compresses but does not invade cortex
• Histology shows whorled pattern, calcification –> psammoma bodies may form

Question 7

Schwannoma

Answer 7

Benign tumor of schwann celsl which myelinate PNS

• involves cranial or spinal nerves, usually CNVIII at CPA (present as loss of hearing or tinnitus)
• tumor cells S-100 positive
• NF2 –> bilateral tumors
• verocay body: alternating bands of aligned nuclei, diagnostic

Question 8

Dysembryoplastic neuroepithelial tumor (DNT)

Answer 8

Childhood onset, seizure disorder, low grade, rarely progresses

• temporal lobe
• microcysts with “floating neurons”

Question 9

Primary Central Nervous System Lymphoma (PCNSL)

Answer 9

mostly diffuse large B-cell lymphomas in elderly

Question 10

Neurocytoma

Answer 10

Low-grade with uniform round nuclei in evenly spaced cells

- young adults

Question 11

Primitive neuroectodermal tumor (PNET)

Answer 11

resemble medulloblastoma, mostly seen in brain