Approximately 10% of pituitary tumors are plurihormonal, most of them
silent from an endocrine point of view. We report here the case of a w
oman with a bihormonal adenoma who presented with Cushing's disease. T
he patient had a previous history of galactorrhea-amenorrhea and had b
een submitted to hypophysectomy. Immunohistochemistry of the adenomato
us tissue revealed the presence of ACTH- and PRL-secreting cells. Seve
n years later, signs and symptoms of Gushing's syndrome developed. A s
econd surgical intervention revealed corticotroph hyperplasia in the r
emaining pituitary tissue. This uncommon course expands the spectrum o
f presentation of pituitary adenomas.