Causes and treatment of recurrent hyperparathyroidism after subtotal parathyroidectomy in the presence of multiple endocrine neoplasia 1.

Abstract

Subtotal parathyroidectomy (SPTX) is the treatment of choice for hyperparathyroidism in a patient with multiple endocrine neoplasia type 1 (HPT-MEN-1). There are scarce data on the causes, timing, and appropriate surgical treatment of patients with recurrent HPT-MEN-1. The aim of this study was to investigate the timing, causes, site of recurrence, and surgical treatment of recurrent HPT-MEN-1 in patients who underwent SPTX. The study was a retrospective review of prospectively collected data on patients with HPT-MEN-1 with SPTX at two referral institutions. The data collected included the following: demographics, duration of follow-up, weight of resected parathyroid tissue, type of remnant, time to reoperation, cause/site of recurrence, and surgical treatment. We studied prognostic factors of recurrence. A total of 69 patients underwent SPTX and were followed for a mean of 75.3 months. After the surgery, 15 patients were left with a single "normal" gland and 54 with a 50- to 70-mg remnant of a partially excised abnormal gland. Nine patients (13%) had a recurrence within a mean of 85 months (12-144 months). Patients with a recurrence had been followed longer (115 vs. 66 months; p = 0.005). Five recurrences occurred in a parathyroid remnant, 3 in a previously "normal" gland; the fifth recurrence was in both a hyperplastic remnant and a fifth gland. Remedial surgery included five subtotal resections and four immediate parathyroid autotransplantations. Two patients had a second recurrence due to a supernumerary gland. Factors related with recurrence are the follow-up time (p < 0.01) and thymectomy (p < 0.003). Recurrence of HPTP-MEN-1 usually is located in preserved parathyroid tissue with no preference for a previously normal gland or a remnant. A second recurrence is most likely seen in a supernumerary gland. Recurrence is associated with the follow-up time and thymectomy.