Remission of Insulin-Dependent Diabetes Mellitus in Multiple Endocrine Neoplasia Type 2A After Adrenalectomy

A 37-year-old man presented with symptoms of polyuria and weight loss over the past year. Initial laboratory examination showed elevated blood glucose level (468 mg/dL [25.9 mmol/L]; normal reference range [RR], 75-109 mg/dL [4.1-6.0 mmol/L]), high glycated hemoglobin A1c (13.2% [120 mmol/mol]; RR, 4.6-6.2% [26-44 mmol/mol]), low urinary C-peptide excretion (17.4 μg/day [5.76 nmol/day]; RR, 18.3-124.4 μg/day [6.0-41.1 nmol/day]), and ketosis, leading to a diagnosis of insulin-dependent diabetes mellitus. Subsequent investigations identified medullary thyroid carcinoma and bilateral pheochromocytomas. Given the detected RET gene variant and the patient's family history of multiple endocrine neoplasia type 2A (MEN2A), the diagnosis of MEN2A was confirmed. Upon hospital admission, intensive insulin therapy was commenced, which resolved the symptoms and normalized blood glucose levels. Subsequently, laparoscopic bilateral adrenalectomy was performed, after which the patient's glucose tolerance normalized, eliminating the need for diabetes treatment and avoiding hypoglycemia. This case highlights the potential for catecholamine-induced suppression of insulin secretion via α2 action on pancreatic β-cells to be remission and rapidly improved by adrenalectomy in individuals with MEN2A experiencing insulin-dependent diabetes mellitus.