OBJECTIVETo study the clinical characteristics, diagnosis and surgical effects of thyroid-stimulating hormone pituitary adenomas (TSH-omas).

METHODSThe clinical data of 19 patients (14 female and 5 male) with TSH-omas were analyzed retrospectively in this study from January 2001 to December 2008. The patients ranged from 20 to 70 years old (average 40.5 years old) and had disease histories from 1 to 228 months (average 55 months). Among these patients, 15 of them complained of thyrotoxicosis symptoms, while the other 4 patients' symptoms were associated with headache and/or visual disturbance caused by the tumor mass effect. Initially, 12 of the 15 patients with thyrotoxicosis symptoms were misdiagnosed with Grave's disease. As a result 2 of them received (131) Iodine, and one received subtotal thyroidectomy. All of these patients underwent transsphenoidal microsurgery.

RESULTSAverage follow-up period was 3.6 years (6 months-7 years). Pathological analysis of the surgical specimen showed pituitary adenoma in all patients, immunohistochemistry were positive for TSH in 17 cases, negative for TSH in 2, positive for growth hormone in 2, positive for prolactin in 1, and positive for adrenocorticotrophic hormone in 1. Postoperative MRI revealed that the tumors in 15 patients were removed totally, though 4 patients still had residual tumors. The thyroid hormone level tests suggested that 13 patients could be considered normal 3 months after their tumors were removed, though 2 of patients with normal postoperative MRI and thyroid hormones showed increased levels of TSH. For these 2 patients, tumors did not recur and their thyroid hormone levels returned to normal after pituitary radiotherapy. The cure rate was 11/19 after surgery and 13/19 after surgery plus pituitary radiotherapy.

CONCLUSIONSThe screening test for hyperthyroidism patients with high TSH levels is a key point to improve the accuracy rate in early diagnoses of TSH-omas. The transsphenoidal microsurgery is first choice to treat TSH-omas, while pituitary radiotherapy and somatostatin analogs are beneficially adjunctive therapies.