Collision lesions of the sella: co-existence of craniopharyngioma with gonadotroph adenoma and of Rathke's cleft cyst with corticotroph adenoma.

Collision lesions of the sellar region are relatively uncommon. Most contributions include a pituitary adenoma or a cyst/cystic tumor, particularly a Rathke cleft cyst. The association of craniopharyngioma with an adenoma is particularly rare. Among reported cases, some have included secondary prolactin cell hyperplasia due to pituitary stalk section effect. Herein, we report two collision lesions, including a gonadotroph adenoma with adamantinomatous craniopharyngioma and a corticotroph adenoma with Rathke's cleft cyst. Clinicopathologic correlation and a review of the literature are undertaken