TSH secreting pituitary tumor — an experience of 20 years follow-up

Thyrotropinoma is a rare pituitary tumor that causes the development of thyrotoxicosis syndrome as a result of hyperproduction of thyroid stimulating hormone (TSH). In the Russian literature over the past 10 years, one case of thyrotropinoma in a child, four cases of TSH-producing pituitary adenoma in women and only one in a man have been described. The article presents a unique clinical case of a 20-years history of observation of a patient with TSH-oma. The rarity of this disease led to the fact that it took more than 10 years to make a correct diagnosis. The first operation of thyroid gland was performed before the diagnosis of pituitary adenoma and inappropriate TSH secretion syndrome. That right hemithyroidectomy was supposed to cure a toxic adenoma of thyroid gland. The diagnosis of thyrotropin-secreting piruitary tumor was established only after 6 years even after finding a combination of pituitary adenoma and thyrotoxicosis. After that, the patient steadfastly refuses neurosurgical treatment, despite the presence of macroadenoma with intrasellar growth. The therapy with somatostatin analogs led to patient’s intolerance with gastrointestinal side effects and hospitalization for acute pancreatitis. The absence of the therapy due to low compliance led to long-term persistence of thyrotoxicosis. The absence of signs and symptoms of expanding tumor mass (visual field defects, loss of vision, headache, partial or total hypopituitarism) demonstrates the slow growth of this kind of pituitary tumor. The long-term effect of elevated TSH levels led to diffuse goiter with compression of the neck organs, and the need of the surgical treatment of the thyroid. Stable euthyroidism after the operation led to stable normoglycemia in the patient with previously diagnosed diabetes mellitus type 2. This fact should keep an attention of physicians and endocrinologists to screen for the secondary reasons of hyperglycemia in a patient with diabetes mellitus manifestation. Long-term history of thyrotoxicosis led to the deleterious effects of thyroid hormone excess on the heart (atrial fibrillation, cardiomyopathy, cardiac failure). Those effects are still observed even after thyroidectomy and medical euthyroidism achievement. This fact demonstrates the importance of early diagnosis and treatment of TSH-omas.