PITUITARY ADENOMAS ARISING far from the pituitary gland occur rarely as a result of defects in embryological migration. Likewise, there have been reports of isolated suprasellar adenomas (clinically nonfunctioning), presumably derived from cells of the pars tuberalis. In this report, we present four cases of functional pituitary adenomas (three adrenocorticotrophic hormone, one prolactin) confined to the supradiaphragmatic region. In each case, the tumors were initially treated unsuccessfully by operations via the transsphenoidal route because of expected intrasellar processes with suprasellar extension.