[Thyrotropin-producing adenomas and thyrotropic hyperplasia (clinical case reports and the review of the literature)].

An increased blood level of the thyroid stimulating hormone (TSH) is usually associated with primary hypothyroidism (PHT) but can also be observed in such rare cases as TSH-secreting pituitary tumor. The article describes four clinical cases of elevated TSH blood levels: 1) TSH-secreting pituitary adenoma with hyperthyroidism; 2) TSH-secreting adenoma with hypothyroidism; 3) hormonally inactive pituitary adenoma combined with primary hypothyroidism; 4) reversible thyrotropic hyperplasia. These clinical situations substantiate the importance of considering different diagnoses in a patient with a pituitary gland tumor associated with an increased TSH blood level.