[TSH-secreting pituitary tumors: two case reports and literature review]

TSH-secreting pituitary adenomas are rare pituitary functioning tumors accounting for less than 2% of the pituitary adenomas. The clinical feature consists of thyrotoxicosis occasionally associated to tumoral symptoms due to mass effect. The biochemical feature consists of elevated thyroid hormones levels and normal or high TSH concentrations. This disease is often wrongly diagnosed as Grave's disease, and the ablative therapy is frequently conducted prior to the diagnosis.

To report two cases followed in the Neuroendocrine Unit of Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo and to review the literature aiming at the management of this affection.

In the presence of elevated thyroid hormone levels associated with inappropriate normal or increased TSH levels, the possibility of a TSH-secreting pituitary adenoma should be considered for the proper medical treatment.