Long-term surgical outcomes in TSH-secreting pituitary adenomas: the hidden burden of asymptomatic hyperthyroidism

Thyrotropin (TSH)-secreting pituitary adenomas, though a rare cause of hyperthyroidism, present significant challenges in management. This study aimed to assess surgical outcomes, remission factors, and postoperative complications.

In this largest single-center retrospective study, we analyzed 177 TSHoma surgical patients (2001-2022), with 152 cases selected for long-term follow-up. Primary outcome was remission; secondary outcomes included postoperative infection and hypopituitarism.

The overall remission rate was 72.4%. Radiologically, patients with Knosp Grade 3-4 tumors (OR = 12.95, 95% CI: 3.65-53.77, p < 0.001), suprasellar involvement (OR = 8.61, 95% CI: 2.66-31.37, p < 0.001) significantly elevated the risk of non-remission. Asymptomatic hyperthyroid TSHomas, despite the absence of overt hyperthyroidism symptoms, comprise 24.3% of cases and are characterized by a significantly lower remission rate (54.1%) compared to mild (82.8%) and severe hyperthyroidism (73.7%), accompanied by larger tumor size [26.0 (19.0-30.0) mm], increased cavernous sinus involvement (38.9%), and more extensive suprasellar extension (43.2%). Postoperative TSH level ≤ 0.183 µIU/ml (AUC 0.752, sensitivity 80.0%, specificity 69.7%) and tumor maximum diameter ≤ 21.5 mm remission (AUC 0.858, sensitivity 81.9%, specificity 81.8%) can serve as simple predictors for remission. The rate of postoperative complications was 7.7% for CNS infection and 15.1% for hypopituitarism, respectively. Notably, CSF leakage significantly elevated the risk of postoperative infection (OR = 37.30, 95% CI: 5.58-507.77, p = 0.001) and hypopituitarism (OR = 5.43, 95% CI: 1.67-18.97, p = 0.006).

Surgical intervention for TSHoma demonstrates a promising remission rate. Asymptomatic TSHomas should be exclusively cautious due to their significantly lower remission rates. CSF leakage correlates with an increased risk of both postoperative infection and hypopituitarism.