Case: A 12- year old boy presents with headache , projectile vomiting and blurry vision. CT scan shows a posterior fossa mass lesion. Histopathologic image of the resected section is seen below.

Answer the questions based on this case
Question 1: Which of the following genetic alterations has the BEST prognosis in this tumor?
A. WNT-activation
B. SHH- activation, TP53 wildtype
C. NMYC-amplification
D. SHH- amplification, TP53 mutated
Question 2: Identify the false statement regarding this tumor.
A. Associated with turcot syndrome
B. Extremely radiosensitive
C. WHO Grade 3
D. TP53 mutation is associated with a bad prognosis
Question 3: Most common cytogenetic abnormality associated with this tumor is?
A. Isochromosome 17q
B. Monosomy 6
C. Isochromosome 12p
D. Balanced translocations
DIAGNOSIS
Diagnosis is medulloblastoma
ANSWER– Question 1
Correct answer is A: WNT-activated medulloblastomas have the best prognosis among all.
SHH- amplification, TP53 mutated medulloblasyomas have a bad prognosis.
ANSWER Question 2
Correct answer is C
🍉Medulloblastoma is WHO Grade 4
🍉Syndromes associated with medulloblastoma- Gorlin syndrome, Turcot syndrome
🍉It is a radiosensitive tumor.
🍉Isochromosome 17q is association with a bad prognosis.
ANSWER Question 3
Correct answer is A
Most common cytogenetic abnormality in medulloblastoma is isochromosome 17 q
WNT-activated medulloblastomas are associated with monosomy 6 and have a better prognosis.
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