Clinical characteristics of adrenocorticotropic hormone independent macronodular adrenal hyperplasia: a report of 30 cases

Abstract

To explore the clinical characteristics of adrenocorticotropic hormone (ACTH) independent macronodular adrenal hyperplasia (AIMAH). A total of 30 AIMAH patients from January 2001 to December 2011 at our hospital were reviewed retrospectively and their clinical data collected. AIMAH was equally distributed between genders. Their mean age was 44 ± 9 years and median course of disease 5 years. Hypertension was the most common clinical manifestation. Circadian rhythm of plasma cortisol disappeared in all patients, and the level of 24 hour urinary free cortisol (24 hUFC) was normal only in 4 (13.3%) patients. Both low and high dose dexamethasone suppression tests were not suppressed in 30 (100.0%) and 28 (93.3%) patients respectively. The stimulation tests for detecting aberrant expression of hormone receptors were performed in 14 patients. At least one aberrant cortisol response was identified in 12 patients. Twenty-five patients underwent adrenalectomy. Among 7 patients of bilateral adrenalectomy, 6 achieved remission while 8 patients did so among 14 patients of unilateral adrenalectomy. AIMAH should be considered in patients with massively enlarged bilateral adrenal glands. Treatment modalities should be decided according to clinical manifestations and cortisol level so as to relieve symptoms and improve prognosis.