Endocrine Abstracts

Background: There is no consensus on the optimal timing of surgery for primary hyperparathyroidism (PHPT) in MEN1. Experienced centres recommend subtotal or total parathyroid surgery with three and a half gland surgery along with thymic removal as a favoured procedure; but long-term outcomes have rarely been reported.

Objective: To investigate the indications and outcomes for surgery in patients with PHPT in MEN1

Methods: Review of case notes, electronic records and clinical material from a cohort of MEN1 patients.

Results: Thirty-five patients with genetically confirmed MEN1 (21F(60%); age 42 years (range 11–83)) were included of whom 34 had PHPT. Twenty-eight of the 34 (82%) have had parathyroid surgery. Of these 28 patients 18 (64%) had significant symptoms of hypercalcemia or renal stones. Severe hypercalcemia with [Ca²⁺] >3 mmol/l was present in only 1/28 patients. The pre-operative calcium was 2.78±0.13 mmol/l (mean±S.D.), the [PTH] was 115±61 ng/l (10–65 ng/l). The favoured operation was 3.5 gland parathyroidectomy (18/28 (64%)), with total performed in 4/28 (14%). At 6 months post-surgery hypoparathyroidism was present in 9/28 (32%), persistent hypercalcemia in 8/28 (29%), and normocalcemia in 13/28 (46%). At longer term follow up 9/13 developed recurrent hypercalcemia. In our series, exon 3 mutation was associated with a higher chance of recurrence of PHPT on follow up.

Summary: Symptoms and renal calculi with elevated servum [Ca²⁺] were the commonest reasons for surgical intervention. Post-operatively 1/3 patients have hypoparathyroidism and in the others recurrence/ persistence of hypercalcaemia occurs in the majority.

Conclusion: PHPT due to parathyroid hyperplasia is a different condition to parathyroid adenoma and applying the same criteria for first surgery in PHPT in MEN1 is inappropriate. In the absence of a standardised approach the decision to operate on parathyroid hyperplasia in MEN1 needs careful consideration, in the knowledge that long-term normalisation of [Ca²⁺] is rarely achieved.