Paediatric and young adult manifestations and outcomes of Multiple Endocrine Neoplasia Type 1

Context: Multiple endocrine neoplasia 1 (MEN 1) is an autosomal dominant disease presenting as hyperplasia and neoplasia of parathyroid, pituitary and enteropancreatic tissues. Over 90% of gene carriers develop phenotypic disease by age 30 years, potentially with onset of asymptomatic disease during childhood and adolescence. Objective: To describe the paediatric and young adult manifestations of MEN 1. Design: Descriptive retrospective study of 180 patients with a common MEN1 genotype. The paediatric and young adult (age <22 years) manifestations were determined using hospital records and disease surveillance data. Results: Primary hyperparathyroidism (PHPT) was identified in 42 patients (mean age 17.2 ± 3.3 years). Parathyroidectomy was performed in 16 (38.1%; mean age 17.8 ± 3.2). Four patients experienced recurrent PHPT (25%), and six (37.5%) developed permanent hypoparathyroidism. Pituitary disease was identified in 13 patients. Prolactinoma was found in nine patients (mean age 16.6 ± 2.6 years) of whom four (44.4%) had macroprolactinoma. Two patients required surgical intervention; dopamine agonists showed efficacy in six patients. Two patients with Cushing's disease were successfully treated surgically. Three patients with nonfunctioning pituitary microadenoma managed conservatively. Pancreatic neuroendocrine neoplasms (pNENs) were diagnosed in 12 patients (mean age 17.0 ± 2.6 years): three patients with insulinoma successfully resected (two resected and one exhibiting perineural invasion) and nine patients with nonfunctioning adenomas (NFAs). Conclusion: Pituitary adenomas, PHPT and pNENs are encountered in the paediatric and young adult MEN 1 population. Successful outcomes are typically achieved using standard medical and surgical paradigms; however, parathyroidectomy was associated with a substantial complication rate.