ASYNCHRONOUS PITUITARY-ADENOMAS WITH DIFFERING MORPHOLOGY

Recurrent pituitary tumors can sometimes pose a diagnostic and therape utic challenge. We report a case of a 43-year-old man who presented tw ice, 13 years apart, with pituitary adenoma marked by headaches, visua l impairment, and no signs of endocrinologic abnormality. At initial p resentation computed tomographic scan documented a pituitary mass erod ing the sellar floor, with suprasellar and parasellar extension. The p atient underwent transsphenoidal surgery and the tumor was classified as a silent corticotroph adenoma, subtype 2. Thirteen years later, cli nical 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 turner, Given these striking morphologic differences, we consider the two ade nomas to represent asynchronous, de novo formations. We conclude that the recurrence of a resected pituitary tumor may also represent a meta chronous development of two distinct pituitary adenomas.