TSH-Secreting Pituitary Tumors: A Case Series and Literature Review

Abstract

Objectives: To present a series of 3 patients with TSHomas and a brief literature review.

Background: TSH-secreting pituitary neuroendocrine tumors (PitNETs) account for <1% of all adenomas observed in surgical series. Most are macroadenomas,and diagnosis can be delayed by up to 9.5 years. Early diagnosis and appropriate treatment can prevent the occurrence of neurological and endocrinological complications. Surgical resection is the first-line treatment. A literature review will be presented to summarize current evidence.

Methods: A retrospective multi-center case series of three patients with confirmed histopathologic and immunohistochemical diagnosis of thyrotropinsecreting PitNET. Information was obtained from physical and electronic records.

Results: Three patients were described: male (100%), mean age 34 (±9) years, with a diagnosis of TSH-secreting PitNET and macroadenomas (100%). The mean tumor volume was 12 cm3. Transsphenoidal endoscopic surgery was performed in 66.6% of the patients, one of whom underwent partial resection and required adjuvant radiosurgery. One patient refused the surgical procedure and was offered radiosurgery as initial therapy. Remission was achieved at 100%. 

Conclusion: Thyrotropin-secreting pituitary adenomas are an uncommon cause of hyperthyroidism. Presurgical treatment
with somatostatin analogs might be effective in reducing TSH-oma size. Surgery can effectively restore euthyroidism (>80%). Radiotherapy is an alternative treatment option. The T3 suppression test is the most sensitive and specific test for confirming complete removal of the adenoma. Recurrence appears infrequent.