Intracranial metastases from pituitary adenoma.

Two patients with histologically benign pituitary adenomas subsequently underwent resections of a frontal and a cerebellar tumour each of which had histological appearances identical to those of classic pituitary adenomas. The frontal tumour was immunoreactive for prolactin, and the cerebellar metastasis was immunoreactive for thyrotropin and gonadotrophins. There was no evidence of residual or recurrent intrasellar pituitary adenoma, nor was there a connection between the frontal or cerebellar masses and the sella turcica. Extracranial tumours have not developed. Both tumours fulfil criteria for diagnosis of pituitary carcinoma. These rare tumours are reviewed with emphasis on diagnosis and management.