title: Invasive pituitary oncocytoma.
abstract: A large invasive pituitary neoplasm, surgically resected by left frontotemporal craniotomy, and thought to represent "chromophobe" adenoma by light microscopy, exhibited ultrastructural features characteristic of oncocytoma. Electron microscopic and immunocytochemical studies showed that the tumor did not possess enhanced secretory activity. The indispensable role of electron microscopy in the identification of this rare neoplasm and especially in the classification of all pituitary tumors is emphasized.
mesh_terms: D000236:Adenoma / Q000473:pathology* / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008854:Microscopy, Electron; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000473:pathology* / Q000648:ultrastructure