Paeds

Question 1

Medulloblastoma (MB) is the most common type of?
Subtypes of medulloblastoma, with some prognostic info and related cytogenetics:

Answer 1

90% of Primary NeuroEctoderm Tumours
Histo subtypes:
1) Classic (90%) favourable prog. Often Shh or WNT.
2) Desmoplastic/Nodular - More favourable. Often Shh. Reticulin fibrers with densly packed
3) Extensive Nodular - Best prog
4) Large Cell/Anaplastic - Worst prog

Molecular genetic subtype:
1) group1 - WNT - 5yr OS 90%. Beta
2) Shh - OS 80%
3) Group III - Worst = 50%
4) Grp IV = 75%

Question 2

Subtypes of medulloblastoma, with key histo features prognostic info and related cytogenetics:

Question 3

The standard of care for medulloblastoma is?

Key factors that decide treatment

Answer 3

GTR (90% recur with GTR alone)
Followed by CSI 4 weeks post (evidence says longer time worse outcome).
Dose = 54Gy/30# 1.8Gy/#, with CSI dose determined by risk group:
Average Risk: CSI = 23.4/13, boost post fossa to 54Gy/30
High Risk: CSI 36/20, bring PF to 54.30.

Followed by x4c of CVP (cyclophos, Vincristin cisPlatinum)

Question 4

A 9-year old presents with MRI showing a large posterior fossa mass. List the differential diagnosis of posterior fossa mass

Answer 4

• BEAM (Brainstem glioma, ependymoma, astrocytoma, medulloblastoma)
• Craniopharyngioma, pineal germinoma, ATRT
• Metastases
• Lymphoma, dysplastic cerebellar ganglioma