Hemorrhagic pituitary adenomas: clinicopathological features and surgical treatment. Forty-five (9.9%) of 453 pituitary adenomas operated on between January 1973 and November 1988 demonstrated hemorrhagic changes at surgery: 24 had a blood collection, 12 had a blood collection associated with hemorrhagic necrosis, and 9 had hemorrhagic necrosis. Thirteen patients (28.9%) experienced the acute symptoms of pituitary apoplexy, whereas another 32 had an "asymptomatic" hemorrhage, that is, the clinical course was comparable to an uncomplicated adenoma. Nineteen tumors (42.2%) showed marked suprasellar extension, 8 (17.8%) showed moderate extension, and 11 (24.5%) showed slight extension; another 2 (4.4%) were laterosellar and 5 (11.1%) were intrasellar. Invasive behavior was present in 32 cases (71.1%) and this may suggest another hypothesis to explain the pathogenesis of tumoral hemorrhage. The incidence of hemorrhagic complications in invasive adenomas with marked suprasellar extension was particularly impressive; therefore, we do not suggest preoperative bromocriptine treatment in this type of tumor. Two of 14 patients operated on by the transcranial route died after surgery, whereas there was no operative mortality in the 31 patients operated on by the transsphenoidal route. It proved advantageous to operate as early as possible, even during the acute phase of pituitary apoplexy. The transsphenoidal approach gave the best results, but to achieve satisfactory late results multidisciplinary treatment was necessary, namely, postoperative radiotherapy in 23 patients, bromocriptine in 12, and endocrine replacement therapy in almost all. In an average follow-up period of 6.2 years, 5 (11.1%) symptomatic recurrences were observed. 