[Manifestations and prognosis of thyrotropin-secreting pituitary adenomas: a case series of three patients]

Among pituitary adenomas, thyrotropinomas were previously considered as extremely rare and resistant to therapy. However, the common use of the sensitive TSH measurement and the improvement of pituitary imaging have modified their clinical and hormonal presentation.

We here report three cases of TSH secreting pituitary adenoma that highlight the great diversity of the clinical, hormonal and morphological presentation, and their better prognosis. In the presence of an inappropriate TSH secretion, the main differential diagnosis is the syndrome of thyroid hormone resistance. The role of somatostatin analogue prior to the surgical treatment of TSH secreting pituitary adenoma is also underlined in this report.

The increasing frequency and early diagnosis of TSH secreting pituitary adenoma may be explained by ultrasensitive methods now used for TSH measurement and progress in pituitary imaging, mainly with MRI. This changing spectrum in the presentation and the excellent response to somatostatin analogues improved in the prognosis of the disease.