title: Asynchronous pituitary adenomas with differing morphology.
abstract: Recurrent pituitary tumors can sometimes pose a diagnostic and therapeutic challenge. We report a case of a 43-year-old man who presented twice, 13 years apart, with pituitary adenoma marked by headaches, visual impairment, and no signs of endocrinologic abnormality. At initial presentation computed tomographic scan documented a pituitary mass eroding the sellar floor, with suprasellar and parasellar extension. The patient underwent transsphenoidal surgery and the tumor was classified as a silent corticotroph adenoma, subtype 2. Thirteen years later, clinical symptoms of a destructive pituitary mass reappeared. This time, the adenoma revealed typical ultrastructural features of an oncocytoma; it had a different immunocytochemical profile from the first tumor. Given these striking morphologic differences, we consider the two adenomas to represent asynchronous, de novo formations. We conclude that the recurrence of a resected pituitary tumor may also represent a metachronous development of two distinct pituitary adenomas.
authors.affiliation: Department of Pathology, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Thodou
authors.forename: G
authors.initials: G
authors.lastname: Kontogeorgos
authors.forename: E
authors.initials: E
authors.lastname: Horvath
authors.forename: K
authors.initials: K
authors.lastname: Kovacs
authors.forename: H S
authors.initials: HS
authors.lastname: Smyth
authors.forename: S
authors.initials: S
authors.lastname: Ezzat
mesh_terms: D000236:Adenoma / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D009377:Multiple Endocrine Neoplasia; D016609:Neoplasms, Second Primary / Q000378:metabolism / Q000473:pathology*; D010911:Pituitary Neoplasms / Q000378:metabolism / Q000473:pathology*