Comprehensive evaluation of thyrotropinomas: single-center 20-year experience

To present a single-center 20-year experience with operated thyrotropinomas, including prevalence, clinical, biochemical and histological characteristics, and postoperative outcomes. Retrospective series of histopathologically-proven thyrotropinomas (1993-2013), divided in two groups: A (active, central hyperthyroidism) and B (silent, no hyperthyroidism). Of 1628 operated pituitary adenomas, 20 were beta-TSH-positive (1.2 %). In increments of 5 years, proportion of thyrotropinomas was 1, 1, 0.04 and 1.77 % respectively. Median follow-up was 10.4 months (1.2-150). Group A: 6 patients (5 men), age 41 +/- A 12 years presented with hyperthyroidism (3), pituitary incidentaloma (2) and acromegaly (1). Tumor diameter was 2.1 +/- A 1.2 cm, FT4 2.68 +/- A 2.73 ng/dL; TSH 6.50 +/- A 3.68 A mu IU/mL. Glycoprotein alpha subunit (GSU) was uniformly elevated. Two patients had biochemical evidence of acromegaly. Tumors were plurihormonal (5 GH-positive); none atypical. Postoperative euthyroidism was achieved in 4 of 6 patients (66 %). Group B: 14 patients (7 men), age 47 +/- A 14 years presented with acromegaly (6), mass effect (4), incidentaloma (3) and galactorrhea (1). Tumor diameter was 2.0 +/- A 1.0 cm. Free T4 (1.00 +/- A 0.24 ng/dL) and TSH (2.02 +/- A 1.65 mIU/L) were lower than in group A (p < 0.01). GSU was elevated in all tested cases. Nine patients had biochemical evidence of acromegaly. Tumors were plurihormonal (12 GH-positive); none atypical. Gross total resection was achieved in 12 of 14 (86 %), and 1 (7 %) recurred. In our series, more thyrotropinomas were operated in recent years. These tumors were often plurihormonal with heterogenous clinical presentation and frequent GH co-secretion. Surgical outcomes were good but long-term follow up is necessary.