Thyrotropin/growth hormone co-secreting pituitary adenoma with pancytopenia: a case report

Thyroid-stimulating hormone (TSH)-secreting pituitary adenoma (TSHoma) is a rare functional pituitary tumor that secretes TSH independently, thus stimulating the synthesis and secretion of thyroid hormone. Its clinical manifestation is central hyperthyroidism, and it is easily misdiagnosed as Graves' disease. At present, the treatment of TSHoma includes surgery, medication, and radiotherapy, and transsphenoidal pituitary surgery remains the first-line treatment.

This case involved a 61-year-old Chinese male with clinical manifestations of weight loss, heart palpitations, and shortness of breath, both thyroid hormone and TSH are elevated. The patient was diagnosed with a TSH/growth hormone (GH) co-secreting pituitary adenoma by serological examination, magnetic resonance imaging of the pituitary gland, and related functional tests. Due to thrombocytopenia and heart disease, the patient was deemed a poor candidate for immediate surgery and was therefore treated with octreotide. Thyroid function tests normalized after medication, and the diagnosis of TSHoma was verified.

Although TSHoma is rare, it is not difficult to diagnose based on clinical presentation, ancillary examination, and functional testing. Thyroid hormone resistance syndrome is very similar to it and is therefore easily misdiagnosed. Early diagnosis and appropriate treatment can effectively control the disease and even achieve a clinical cure.