Reversible panhypopituitarism caused by a suprasellar aneurysm: the contribution of mass effect to pituitary dysfunction.

A case of panhypopituitarism and hyperprolactinemia caused by a giant intracranial aneurysm is presented. The case is unique because both the pattern of the pituitary dysfunction and the complete normalization of all pituitary function after decompression of the aneurysm demonstrate the importance of pure compressive effects of mass lesions on pituitary function. The literature regarding return of pituitary function after resection of sellar and suprasellar masses is reviewed, and a schema for classification of pituitary dysfunction caused by mass lesions is proposed.