A case report of primary bilateral macronodular adrenal hyperplasia caused by a novel ARMC5 gene variant

This case involves a 59-year-old man with long-standing poor control of blood glucose and blood pressure. Endocrinological evaluation revealed suppressed ACTH levels, loss of circadian cortisol rhythm, and failure of cortisol suppression after low-dose dexamethasone suppression test. Imaging showed multiple bilateral adrenal nodules. Histopathological examination confirmed nodular lesions composed of clear, lipid-rich cells. Genetic testing identified a novel nonsense variant ARMC5 c.2125C > T (p.Q709). The patient was diagnosed with primary bilateral macronodular adrenal hyperplasia. Following left unilateral adrenalectomy, there was a reduction in antidiabetic and antihypertensive medications with improved glycemic and blood pressure control. This case confirms that this rare endocrine disorder can be caused by ARMC5 gene variants.