Twenty-three cases were identified. The mean patient age was 54 years. The female:male ratio was 1.5:1. Follow-up ranged from 1 month to 23 years (median, 134 months). Mean preoperative calcium was 12.9 mg/dL. Median parathyroid hormone was 290 pg/mL. Two patients (9%) had an asymptomatic presentation, and five (22%) presented with a palpable neck mass. Only nine (39%) underwent initial comprehensive en-bloc resection. Median survival was 22 years. Five- and 10-year survival was 85.9% and 69