Malignant Pituitary Tumors

Abstract

Adenohypophysial tumors usually grow in an expansive manner. The primary effects of tumors without positive endocrinological symptoms result from compression of the normal pituitary gland or nearby neuronal structures—particularly the optic chiasm and optic nerves. Expansive growth can give rise to extremely large tumors that compress the third ventricle or erode the sphenoid bone. There is a minority of tumors with locally invasive growth extending beyond the durai capsule into the cavernous sinus, middle cranial fossa, temporal lobe, diencephalon, clivus, sphenoid sinus, and epipharynx. A small number of tumors may metastasize to the subarachnoid space remote from the primary lesion, to extracranial organs via the blood circulation, or to both (Table 13).