Multiple Endocrine Neoplasia Type 1 (MEN1) is an inherited autosomal dominant disorder caused by mutations in the MEN1 tumor suppressor gene. Penetrance increases with age. It combines mainly hyperparathyroidism, adenomas of the pancreas and pituitary gland. The prevalence is about 2/100 000. Diagnosis in children is rare except in the case of family screening. We report the diagnosis of a familial MEN1 whose index case was an adolescent girl investigated because of hypoglycaemia. A 13-year-old girl presented with several episodes of immediate postprandial confusion. Blood glucose at the time of confusion was 21 mg/dl and insulin level was 18.2 μU/ml, diagnosing hyperinsulinism. Pancreatic MRI showed a 15-mm nodular lesion likely corresponding to an insulinoma. The systematic search for possible MEN1 involvement in the girl led to the diagnosis of asymptomatic primary hyperparathyroidism (Ca 2.84 mmol/l, PTH 45 pg/ml). Family history showed renal lithiasis in the father, which prompted the search for primary hyperparathyroidism (Ca 2.75 mmol/L, PTH 108 pg/ml). A c.136del mutation of MEN1 was identified in the girl. Surgery allowed for the removal of the insulinoma, and found a second 10 mm-adenoma which was removed at the same time, corresponding to an asymptomatic glucagonoma. The diagnosis of familial MEN1 can originate from a pediatric index case. In children, the occurrence of pancreatic adenomas, pituitary adenomas, or primary hyperparathyroidism must lead to the careful record of the familial history, and the screening of MEN1 gene mutation.
27 - 29 Sep 2018
European Society for Paediatric Endocrinology