Introduction: A 55-year-old female, hypertensive, diabetic and smoker, sought care due to symptoms
of heat intolerance, weight loss and excessive sweating 2 years ago. He also noticed
clinical signs of acromegaly, such as increased hand and face size in this period.
During the previous year, hyperthyroidism was diagnosed and tapazole therapy was instituted.
Due to the poor treatment response, she followed an investigation with magnetic resonance
imaging (MRI) of the skull, which revealed an expansive lesion regions of 2.6 × 1.9 × 1.6 cm
compromising the selar and left parasselar regions probably related to the pituitary
adenoma. The lesion extensively involved the left cavernous sinus, involving the internal
carotid artery by up to 180°. Previous laboratory tests demonstrated elevation of
TSH, free T4, T4 and IGF1. The patient was then submitted to surgical resection of
the lesion by endoscopic transsphenoidal approach. The tumor was removed subtotally
due to its proximity to the carotid artery and there were no intercurrences during
the procedure. Immunohistochemical analysis confirmed the secretion of GH, TSH and
prolactina
Discussion: TSH-secreting tumors or thyrotropinomas are a rare form of pituitary adenomas and
correspond to 0.5–2% of all pituitary neoplasms. Excessive TSH production leads to
central hyperthyroidism due to thyroid stimulation. More rarely, it can secrete other
hormones, such as prolactin and GH, and lead to related clinical syndromes. The mean
age of incidence is 40 years and the female sex is slightly more affected. The clinical
presentation is related to hyperthyroidism, which may present subclinically to severe
forms that require intervention due to cardiac complications. In addition to the endocrine
syndromes, it may have suprasellar repercussions and cause anopsis related to chiasmatic
compression. The diagnosis of thyrotropinoma is performed with the visualization of
the expansive lesion on MRI, and the increase of TSH, free-T4 and free-T3. Immunohistochemical
confirmation may help when elevation of hormones is not marked. Treatment usually
involves surgical resection and remission of symptoms occurs in about 60% of patients.
Post-resection hypothyroidism is uncommon.
Conclusion: Although rare, thyrotropinin should be suspected in patients with elevated thyroid
hormones and TSH
