A 59 year-old man with sellar lesion.

A 59 year-old man presented with a large sellar mass. Pathologic examination revealed a tumor with two distinct cell populations. The majority of the tumor showed typical pituitary gonadotroph adenoma morphology and staining. Diffusely scattered throughout this tumor were nests of epithelial cells with an appearance typical of adamantinomatous craniopharyngioma and that were proliferating by Ki-67. Moreover, their diffuse distribution within the adenoma portion of the tumor suggests that these areas arose from within the adenoma where squamous rests are not observed. While pituitary adenomas juxtaposed to craniopharyngiomas have been reported, these cases have consisted of distinct masses unlike the intimately admixed tumor described in this case. Moreover, all previous reports of craniopharyngiomas with pituitary adenoma have consisted of prolactinomas. This is the first reported case of a craniopharyngioma with gonadotroph adenoma.