The Effect of Octreotide LAR on GH and TSH Co-Secreting Pituitary Adenoma

Abstract

1 , and Radiology 2 , Keimyung University School of Medicine, Daegu, Korea Growth hormone (GH) and thyroid stimulating hormone (TSH)-secreting pituitary adenomas are very rare and they account for only 0.5% for all pituitary adenomas. These adenomas are usually treated with surgery, but this surgery is not easy because the tu - mor is usually huge and invasive. We reported here on a case of a GH-TSH-secreting adenoma in a 23-year-old male patient who was initially treated with octreotide LAR. He presented with symptoms of headache, palpitation and a visual defect that he had for the 3 months. He had hypertrophy of the frontal bone and enlargement of both the hands and feet. The visual field test showed bi - temporal hemianopsia. The laboratory examinations showed high serum levels of free T4, TSH and free alpha-subunit. Additionally, the serum levels of GH and insulin-like growth factor-I (IGF-I) were increased. GH was not suppressed below 1µg/L by an oral 75g glucose loading test, and TSH was not stimulated by thyrotropin-releasing hormone (TRH). Because sellar MRI showed invasive macroadenoma encasing the vessels, we initially tried octreotide LAR for treatment. A year later, the IGF-I and thyroid function tests were normalized and the size of the tumor was reduced with cystic change. The symptoms of palpitation and headache were im - proved without a change of the visual field defect. ( Endocrinol Metab 25:378-381, 2010)