OBJECTIVEThyroid-stimulating hormone (TSH)-expressing pituitary adenomas are a rare but important entity with a spectrum of clinical manifestations. There are currently no data to indicate whether a difference exists in the natural progression of active and silent TSH-expressing pituitary adenomas (defined by the presence or absence of clinical hyperthyroidism, respectively). Here we report our experience (including presenting symptoms, treatment, and outcome) with managing both groups over 11 years in the largest single-center study published to date.METHODSWe reviewed retrospectively all patients with histopathologically proven TSH-expressing pituitary adenomas who presented to our center between 2002 and 2012. Data reviewed included clinical presentation, biochemical status, tumor size, management, histopathologic results, and long-term postoperative outcomes.RESULTSA total of 32 patients (16 male) were identified from a total of 902 operations for pituitary adenomas performed between 2002 and 2012. Mean follow-up was 6.7 years. One-quarter (25%) of patients were clinically hyperthyroid at presentation. Visual disturbance was the commonest presenting complaint in 34%. All patients underwent transsphenoidal surgery. Thirty-one percent of patients had a recurrence. The clinically active and silent TSH-expressing pituitary adenomas behaved in a similar manner with respect to recurrence rates.CONCLUSIONSTSH-expressing pituitary adenomas present with a wide clinical spectrum. Visual disturbances are common. Despite radiologic evidence of clearance after surgery and extended follow-up, they may still recur whether clinically "active" or "silent." Our data support the need for close, long-term follow-up of these patients.