Thyroid-Stimulating Hormone-Secreting Pituitary Adenomas : Single Institutional Experience of 14 Consecutive Cases

Objective : Thyroid-stimulating hormone (TSH)-secreting pituitary adenoma (PA) is an extremely rare functioning form of PA that accounts for 0.7-2% of all such cases. The previously reported outcomes of the surgical removal of TSH-PA are poor. Owing to its extremely low incidence, most available reports on TSH-PA are case reports or small case series. Thus, we investigated the clinical and endocrinological outcomes of surgically treated TSH-PA through our institutional series. Methods : We retrospectively reviewed 14 consecutive cases of surgically treated TSH-PA, focusing on the clinical, radiological, surgical, and endocrinological data. Results : There were seven male (50%) and seven female (50%) patients. The mean age was 42.5 years (range, 19-63). The mean tumor size was 16.6 mm (range, 4-30). Optic chiasm compression was noted in six patients (42.9%), and no patient showed cavernous sinus invasion. Thirteen of 14 patients (92.8%) underwent transnasal transsphenoidal approach (TSA), and one patient underwent TSA followed by transcranial approach for residual tumor removal. Thirteen of 14 patients (92.8%) showed endocrinological remission; all patients who experienced remission showed subnormal levels of TSH (<0.4 μU/mL) on postoperative day 2. Recurrence occurred in two patients (14.2%). One patient underwent subsequent revision transnasal TSA for recurrent tumor removal, and the other patient underwent gamma knife radiosurgery for recurrence. Conclusion : Surgical treatment showed excellent surgical outcomes. The TSH level in the immediate postoperative period may be a predictor for endocrinological remission.