A case of GH and TSH secreting pituitary macroadenoma

A case of GH and TSH secreting pituitary macroadenoma is reported. A 45-year-old female presented clinical features of acromegaly (the abnormal growth of the hands and feet, with lower jaw protrusion), diabetes mellitus, hypertension, nodular goiter and hyperthyroidism of unclear origin. NMR pituitary imaging revealed intra and extrasellar tumor. The laboratory examinations showed very high plasma levels of GH and IGF-1 and normal level of TSH coexisting with high plasma levels of free thyroid hormones. Pharmacological pretreatment with somatostatin analogues caused the substantial reduction of GH and TSH plasma levels. Histological and immunohistochemical examination of the tissue obtained at transsphenoidal surgery showed GH and TSH secreting adenoma. The laboratory examinations after surgery showed normal GH and IGF-1 plasma levels and reduced insulin requirement, what indicates radical operation. The very low plasma levels of TSH and free thyroid hormones after surgery and immunohistochemical examination suggest central hyperthyroidism due to TSH secreting pituitary tumor (thyrotropinoma).