Review of the Childhood Primary Brain Tumors for your Step 1 Prep

[drhma]

Review of the Childhood Primary Brain Tumors:


1. Pilocytic ASTROCYTOMA (“Pilocytic” refers to hair-like, which often describes the presence of long processes such as Rosenthal fibers)

A – composed of Astrocytes (“astrocytes are fabulous” so GFAP positive)
S – slow-growing cysts, benign, good prognosis
T – the most common childhood primary brain tumor in children. The peak age of occurrence is between 8 and 13 years of age
RO – Rosenthal fibers (eosinophilic, corkscrew fibers) are present


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Above: Rosenthal fibers, varying in amount from a few to substantial. Eosinophilic granular bodies are aggregates of eosinophilic globules and they are often found in pilocytic astrocytoma. Their presence is related to the benign nature of these tumors.

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2. MEDULLOBLASTOMA – can compress the forth ventricle causing hydrocephalus (the 4th ventricle is located just inferior to the medulla within the brainstem, so medulloblastoma compresses the segment of CSF circuit adjacent to the medulla)

M – Malignant – highly malignant cerebellar tumor.
ED – primitive neuroectodermal tumor (PNET)
BLASTOMA – composed of primitive cells (blasts) that form homer wright rosettes.


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Above: Homer Wright rosettes seen in Medulloblastoma

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3. EPENDYMOMA – ependymal cell tumor commonly found in 4th ventricle Can cause hydrocephalus, poor prognosis. Tumor cells are usually hobnail shaped and often contain small cytoplasmic granules, blepharoplasts near nuclei

E – ependymal cells
PE – perivascular pseudorosettes


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Above: Perivascular pseudorosettes and blepharoplasts are characteristic of ependymomas

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4. HEMANGIOBLASTOMA – toriginate from the vascular system (hence the name – hemangio)

Foamy cells and high vascularity are characteristic
Can produce Epo and cause secondary polycythemia


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Above: Thin-walled blood vessels with interposed xanthomatous stromal cells characterize hemangioblastoma

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5. CRANIOPHARYNGIOMA – most common childhood supratentorial tumor. Derived from Rathke’s pouch. Calcifications are common. Can produce bitemporal hemianopia


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i hope that the links for the images worked! best of luck everybody!! i hated that page in first AID,, finally done with the childhood brain cancers!