Parapituitary tumours are rare and of these, craniopharyngiomas, evolved embryologically from Rathke's pouch, are the most common.
Other tumours may compress the pituitary stalk and cause hypopituitarism; these include meningiomas arising from the sphenoidal ridge and, very rarely, germinomas and chordomas. Metastases from lung and breast carcinomas to the hypothalamus and pituitary are well documented, but rare.
