Diagnosis of hyperthyroidism does not present serious difficulties currently. Distribution of imaging techniques increasing the detection of pituitary adenomas every year. Thyrotropin-producing adenoma is a rare cause of hyperthyroidism. Early detection will alert its errors in treatment strategy, unjustified surgery on the thyroid gland, and will improve the quality of patients life. The article presents two clinical cases of thyroid-stimulating hormone (TSH)-secreting pituitary adenomas in patients with different disease duration, and thus the presence of hyperthyroidism complications. Both patients were operated in the Federal Center of Neurosurgery Novosibirsk by transnasal transsphenoidal approach. The resistant euthyroidism was reached postoperatively, but in patients with long-term history of the disease, large size of adenoma in the postoperative period developed secondary adrenal insufficiency and her quality of life is significantly lower, taking into account comorbidities. The period of follow-up consists 3 years and one year respectively.