The following are true of Adamantinomatous craniopharyngioma except
A. Adamantinomatous variant is common in adultsB. metastatic calcification seen
C. wet keratin is diagnostic
D. palisading of squamous epithelium seen
E. arises from the vestigial remnants of rathke’sPouch
Ans.
A,B
The
craniopharyngioma is thought to be derived from vestigial remnants of Rathke
pouch. These slow-growing tumors account for 1% to 5% of intracranial
tumors; a small minority of these lesions arise within the sella, but most are suprasellar, with or without
intrasellar extension. A bimodal age distribution is observed, with one peak in childhood (5 to 15
years) and a second peak in adults 65 years or older. Two distinct histologic
variants are recognized: adamantinomatous craniopharyngioma (most often
observed in children) and papillary craniopharyngioma (most often
observed in adults).
The adamantinomatous type frequently contains radiologically demonstrable
calcifications; the papillary variant calcifies only rarely.
Adamantinomatous
craniopharyngioma consists of nests
or cords of stratified squamous epithelium embedded in a spongy
“reticulum” that becomes more prominent in the internal layers. “Palisading” of the squamous epithelium is frequently observed
at the periphery. Compact, lamellar keratin formation (“wet keratin”) is a diagnostic feature of this tumor. As was
mentioned above, dystrophic calcification is a frequent finding. Additional features include
cyst formation, fibrosis, and chronic inflammatory reaction. The cysts of
adamantinomatous craniopharyngiomas often contain a cholesterol-rich, thick
brownish-yellow fluid. These tumors extend fingerlets of epithelium into
adjacent brain, where they elicit a brisk glial reaction.
