Ectopic pituitary adenomas.

We report here four cases representing different forms of ectopic pituitary adenomas localized: (1) in the nasal cavity, (2) in the sphenodial sinus, (3) on the sphenoidal wing and (4) on the petrous temporal bone. Ectopic pituitary adenomas may probably occur in extrasellar pituitary tissue deposited along the route of fetal development or as a result of intracranial dissemination of adenomatous cells during operation. It is assumed that in some cases ectopic pituitary tissue may retain endocrine function leading to a sustained pituitary function even after a radical hypophysectomy.