The clinical and biochemical features in 26 patients with prolactinoma before and after transsphenoidal microresection

Abstract

Abstract. Twenty-six women, 16 to 40 years of age, with amenorrhoea with or without galactorrhoea and abnormal pituitary fossa tomogram were studied before and after transsphenoidal resection of their pituitary adenomas. The immunoreactive serum prolactin (Prl) was abnormally high both before and after intravenous (iv) administration of thyrotrophin-releasing hormone (TRH) but the rise was blunted. The serum Prl level returned to normal post-operatively in 20 patients, but the subnormal rise after TRH persisted in 23 patients. The basal serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were normal before and after surgery. The peak serum level of LH after administration of the luteinizing hormone-releasing hormone (LRH) was normal but the peak FSH was significantly high before surgery (P < 0.001) and returned to normal post-operatively. Plasma oestradiol (Oe2) was significantly low compared to that after surgery (P < 0.001). Plasma testosterone (T) was significantly higher before surgery than that found in normal women (P < 0.001) and the level fell post-operatively. Plasma androstenedione (A) was higher before surgery than found in normals, but the difference was not significant (P < 0.2). Post-operatively, 23 patients regained their normal menses. Three of these 23 patients continued to have high serum Prl but the serum Oe2 returned to normal. Sixteen of 20 patients who desired pregnancy became pregnant post-operatively. None of the patients required hormonal replacement after surgery. These data indicate that the measurement of LH or FSH at basal and after LRH stimulation, may not be of significant prognostic importance compared with serum Prl and plasma Oe2. Regular menses and pregnancy can occur in some patients in spite of moderately high serum Prl but normal plasma Oe2 levels. Surgical resection of prolactinoma has low morbidity with a high incidence of success resulting in return of normal menses and fertility. The persistent subnormal rise of Prl after TRH post-operatively in the majority of the patients suggests that long-term follow-up for evidence of recurrence is indicated.