Malignant craniopharyngioma

Craniopharyngiomas are histologically and cytologically benign epithelial t umors of the central nervous system that may be locally aggressive and tend to recur after excision. Malignant change in craniopharyngiomas is extreme ly rare; we found only 4 such reports in the literature. In this report, we describe a case of squamous cell carcinoma arising in a previously benign craniopharyngioma in a 42-year-old woman. The patient was diagnosed with cr aniopharyngioma in 1982; during the subsequent 15 years she experienced 7 t umor recurrences, for which surgical resections and 3 courses of radiothera py were performed. In 1998, the tumor recurred with involvement of the nasa l cavity and sphenoid and ethmoid sinuses. Histologic evaluation revealed f oci of typical adamantinomatous craniopharyngioma associated with a moderat ely differentiated squamous cell carcinoma. The transition of typical crani opharyngioma to squamous cell carcinoma was well demonstrated, suggesting t hat carcinoma arose from the underlying craniopharyngioma. Radiation may ha ve been a contributing factor to carcinogenesis in this case.