Endocrine Abstracts

Primary hyperparathyroidism (PHPT) is commonly the first and most frequent clinical manifestation in MEN1 occurring in up to 95% of patients. Surgery is considered the treatment of choice. Clinical course differs to that of sporadic PHPTH in terms of age of onset, complications, surgical management and recurrence rates. This study aims to review the challenges of PHPT in MEN1. Retrospective analysis of patients attending a dedicated MEN1 clinic in the Royal Victoria Hospital, Belfast, under long-term review was carried out (n = 26). 85% had PHPT (n = 22; male:female 9:13; age 49.9: range 28-70 years); making it the most common manifestation. It was the initial presentation in 17 of these 26 patients. Average age at diagnosis of PHPT was 31 years. At diagnosis, average calcium level was 2.86 mmol/L and PTH 106 pg/mL. Fourteen patients had DEXA scan; all reported either osteopenia (43%) or osteoporosis (57%). Renal calculi occurred in 22.7% of this cohort. All patients underwent parathyroidectomy. Main surgical technique used in the first operation was subtotal parathyroidectomy (3 or 3.5 gland removal) (20 of 22 patients). Limited parathyroidectomy (2 gland removal) was employed in 2 patients. Persistent and recurrent disease was diagnosed in 9% and 54.5% of these patients, respectively, after first surgery. Recurrence occurred on average 13 years after first surgery. Rate of remission after first surgery was low at 36.3%. Five patients required a second surgery (3 achieved remission) and 1 patient required a third operation (now in remission). Post-operative hypoparathyroidism was seen in 31.8% of patients. The experience in N.I of MEN1-related PHPT is similar to other studies. This is a multi-glandular disease of which management is challenging. Age of onset is younger in MEN1 related PHPT compared to sporadic PHPT. Recurrence rates are much higher compared with sporadic disease (54.5% vs 1 to 15%). Effects on bone health are more severe in MEN1 (57% vs 40% in sporadic PHPT). Occurrence rates of nephrolithiasis were found to be similar in this study. The timing of surgery requires multi-disciplinary involvement with close and long term follow up, ideally at a dedicated clinic to allow optimal outcomes.