Metastatic Insulinoma in a 16-Year-Old Adolescent Male With Men-1: A Case Report and Review of the Literature

ABSTRACT Objective: Multiple endocrine neoplasia type 1 (MEN-1) is an autosomal dominant condition associated with various combinations of endocrine and nonendocrine tumors. Insulinomas are rare endocrine tumors in the pediatric age group and may be associated with MEN-1 in 10% of cases. Malignant insulinomas only constitute 5 to 10% of all the insulinomas and are exceedingly rare in children. There are only 11 cases of malignant insulinoma reported in the literature in the pediatric age group. Methods: We are reporting a 16-year-old adolescent male who presented with symptoms of hypoglycemia for the 4 months prior to referral. Results: He was diagnosed with malignant insulinoma with multiple metastases to liver and was treated with surgical resection followed by octreotide treatment. He had additional findings consistent with the diagnosis of MEN-1, including elevated prolactin levels combined with a 4 to 5 mm pituitary lesion possibly due to prolactinoma and mildly elevated calcium levels with a parathyroid ultrasound demonstrating a parathyroid adenoma on the left side measuring 8 × 6 × 4 mm in diameter. He has been free of symptoms and radiologic findings of recurrence of insulinoma 1-year post surgery. Conclusion: Malignant insulinoma is extremely rare in children, but should be considered in cases of hyperinsulinemic hypoglycemia. MEN-1 should also be considered because insulinoma may be the first finding of MEN-1. Surgical resection is the treatment of choice. Somatostatin analog is a safe and effective treatment in children in cases with metastatic insulinoma when residual tumor is present. Abbreviations: MEN-1 = multiple endocrine neoplasia-1 MRI = magnetic resonance imaging