MACS

Mild autonomous cortisol secretion, or MACS, represents subtle hypothalamic-pituitary-adrenal axis dysregulation most frequently encountered during the workup of adrenal incidentalomas. Defined primarily by a post-one-milligram dexamethasone suppression test cortisol level exceeding 1.8 micrograms per deciliter in the absence of overt Cushingoid physical features, this biochemical state lacks classic signs but carries significant cardiometabolic morbidity. Pathophysiologically, sustained low-grade hypercortisolemia exacerbates insulin resistance, hypertension, dyslipidemia, and vertebral skeletal fragility. Clinical management hinges on individualized risk stratification: optimizing medical therapy for metabolic and bone complications while evaluating unilateral laparoscopic adrenalectomy for younger patients or those with rapidly progressing, refractory metabolic comorbidities.