Improvement in Hyperglysemia Following Unilateral Adrenalectomy for ACTH-Independent Macronodular Adrenal Hyperplasia (AIMAH) : A Case Report

Adrenal corticotropin (ACTH) -independent macronodular adrenal hyperplasia (AIMAH) is a rare cause of Cushing’s syndrome. Bilateral adrenalectomy is the treatment of choice, but lifetime steroid replacement is essential. Here we report a case of AIMAH whose hyperglycemia was improved following unilateral adrenalectomy. A 42-year-old woman with serious intellectual disability and intractable epilepsy presented with polydipsia. Casual blood glucose and hemoglobin A1c (HbA1c) were 322 mg/dl and 8.5%, respectively. The cortisol level was high and ACTH level was low. Abdominal computed tomography and magnetic resonance imaging revealed unsuspected macronodular enlargement of bilateral adrenal glands (left 8 cm, right 4 cm in maximal diameter) and she was diagnosed with AIMAH. Both adrenal glands showed intense 131 I-adosterol accumulation predominantly in the left side and left-unilateral laparoscopic adrenalectomy was performed. Both insulin and oral antidiabetic drugs could be cancelled postoperatively, and HbA1c decreased to 5.7%. Steroid was not replaced but she never experienced adrenal crisis. We conclude that unilateral adrenalectomy is a safe and effective treatment for certain cases of AIMAH.