TSH, prolactin and GH-secreting adenoma: case report

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