A series of 84 patients with pituitary adenomas greater than 1 cm in diameter is presented. Full preoperative and postoperative endocrine evaluations were carried out, and the effects of transsphenoidal surgery on remaining anterior pituitary function were analyzed. Of the patients who had normal anterior pituitary function before surgery, 78% retained normal function after surgery. Thirty-three percent of those patients with pituitary deficits who did not have panhypopituitarism before surgery had improved function after surgery; 33% had worsened function after surgery. None of the patients with panhypopituitarism before surgery regained function after surgery. Transsphenoidal surgery carries an acceptable risk for sacrificing anterior pituitary function, but the risk is greater in patients with larger tumors and preoperatively compromised pituitary function.

Forty-five patients with galactorrhea-amenorrhea were followed during a period of 1 to 8 years (mean 3.1) after transsphenoidal prolactinoma removal. The ratios of patients who appear to be cured to the total numbers treated were 20 patients of 27 with grade I tumors; six of 10 with grade II; two of five with grade III; and none with grade IV tumors. Six patients with normal prolactin levels one week postoperatively had relapse later, as did three with normal prolactin levels 2 months postoperatively. A normal prolactin level 6 months postoperatively predicted ultimate cure. The 19 pregnancies that occurred in 15 patients, four with high prolactin levels, were uneventful. Prolactin rose normally with pregnancy and returned to prepregnancy level in all but one patient. Prolactin responses to stimulation tests were blunted for 6 months after successful tumor removal. By 1 year, responses to thyrotropin releasing hormone and metoclopramide tests were returning to normal, although responses to chlorpromazine and hypoglycemia remained blunted. The postoperative inhibition of normal lactotropes for 6 months is suggested. Ultimate cure cannot be determined before 6 months and conception should be deferred until then.

TRH, metoclopramide (MCP), chlorpromazine (CPZ), and insulin (ITT) stimulation tests of PRL secretion were carried out in age-matched controls and before and after successful removal of pituitary prolactinomas in women with the galactorrhea-amenorrhea syndrome. In preoperative patients there was a blunted or absent PRL response to TRH in 87%, to MCP in 100%, to CPZ in 100%, and to ITT in 93%. Two to 6 months after successful tumor removal, serum PRL rose 2-fold (the usual criterion for a normal response) in 73% after TRH, in 100% after MCP, but in only 13% after CPZ and in only 14% on ITT. However, the PRL increment with all four tests was significantly lower than that in normal controls. One to 8 yr after successful surgery, the PRL increments after TRH and MCP were returning to normal, but the PRL responses to CPZ and ITT remained blunted. GH, ACTH, and TSH reserves were intact in all patients. The diminished PRL response to all stimulation tests observed up to 6 months postoperatively might be explained by the persistence of a negative feedback effect from high PRL levels associated with the tumor. The more persistent impairment of the PRL response to CPZ and ITT is unexplained but suggests a hypothalamic defect.

TRH and metoclopramide tests were performed in 10 female patients with presumed phenothiazine-induced hyperprolactinemia to define the serum PRL response to these agents. Our results show that the serum PRL response to metoclopramide is blunted in most patients with phenothiazine-induced hyperprolactinemia, and the serum PRL response to TRH is exaggerated in most patients during and 3 weeks after stopping phenothiazines.

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