Surgical treatment of adrenocorticotropin-independent macronodular adrenal hyperplasia

Abstract

Objective To investigate the diagnosis and treatment of adrenocorticotropin-independent macronodular adrenal hyperplasia (AIMAH). Methods The clinical data of 14 cases of AIMAH from August 1972 to July 2010 were retrospectively analyzed.The cases included 5 males and 9 females with a mean age of 45 (range 26 to 58 ) years.Ten patients demonstrated typical Cushing's syndrome (CS) and 4 patients presented with weight gain,hypertension or diabetes mellitus without any signs of CS.The circadian rhythm of serum cortisol was abnormal.Low and high dose dexamethasone suppression tests failed to suppress cortisol secretion.CT scan showed bilateral enlargement of the adrenal glands with multiple macronodules.All patients underwent open surgery,including 5 cases of unilateral adrenalectomy,6 cases of adrenalectomy combined with contralateral subtotal adrenalectomy and 3 cases of bilateral adrenalectomy.Results It was established by pathological examination that all patients had bilateral adrenal macronodular or adenomatoid hyperplasia.During the mean follow-up of 69 months (range 12 to 120 months),the clinical symptoms of CS disappeared after surgery in all cases.The 5 patients who received unilateral adrenalectomy had urinary free cortisol and serum cortisol within normal ranges and no further enlargement of the contralateral gland was noticed.Among the 3 patients who received bilateral adrenalectomy,1 case died of adrenal crisis on day seven post-operation.The remaining 2 cases presented with adrenal insufficiency but returned to normal after glucocorticoid replacement therapy.Nelson's syndrome was not observed in the other patients.Conclusions AIMAH has unique endocrinological and pathological features,presenting as an independent etiology of CS.Unilateral adrenalectomy appears to be an effective and safe alternative treatment for AIMAH and long-term remission can be achieved.Bilateral adrenalectomy or unilateral adrenalectomy combined with contralateral subtotal adrenalectomy may be performed if the symptoms have not improved or recurred after unilateral adrenalectomy. Key words: Cushing syndrome; Adrenocorticotropic hormone; Macronodular adrenal hyperplasia; Surgical procedures, operative