The coexistence of pituitary adenomas and meningiomas: three case reports and a review of the literature.

A coexistence of pituitary adenomas and meningiomas is very rare. We have reported on three of our own cases and reviewed the 17 cases reported in the literature. One has to differenciate between the coexistence of a pituitary adenoma and a meningioma without previous irradiation, and the occurrence of a meningioma following the irradiation of a pituitary adenoma. In the cases without irradiation, the adenoma and the meningioma are diagnosed simultaneously. On the other hand meningiomas arising after irradiation of a pituitary tumour are usually diagnosed only after a long latent period. The coexistence of pituitary tumours and meningiomas resulting from hormone dependent growth as well as the induction of growth of meningiomas by irradiation are discussed.