Endocrine Abstracts

Introduction: Bilateral macronodular adrenal hyperplasia ACTH-independent (BMAH) represents less than 1% of the causes of Cushing’s syndrome (CS). Studies have shown that mutations in the gene ARMC5 are a common cause of family BMAH and are associated with severe clinical disease and the development of meningiomas.

Case report: 64-years-old man presented to our consult due to bilateral macronodular adrenal hyperplasia. He had diabetes mellitus, arterial hypertension, dyslipidemia and coronary heart disease. The physical exame showed excess weight (weight 81 kg, height 1.65 m, BMI 29.7 kg/m²), bruising, facial rubeosis, skin atrophy and deposition of cervical dorsal fat. Laboratory work up revealed ACTH-independent CS: ACTH<1 ng/l (ref.v.<63.3), serum cortisol after 1 mg dexamethasone suppression test 27.6 μg/dl, urinary free cortisol (UFC) 520 μg/dl (ref.v. 36–137) and serum cortisol after low-dose dexamethasone test 24 μg/dl. He underwent research of ectopic adrenal hormone receptors with positive response (under β-blocker and angiotensin receptor antagonists) and partial (after discontinuation of these drugs) in the posture test and negative response to the others tests. The patient would be subjected to adrenalectomy, but due a complication during surgery, he performed just right adrenalectomy. Histological results confirm macronodular adrenal hyperplasia. Genetic study was preformed and a ARMC5 mutation in heterozygosity (c.1379T>C) was identified in adrenal and blood. Patient is currently with no evidence of CS: UFC 36.3 μg/dl, salivar cortisol 0.180 and 0.193 μg/dl (ref.v.<0.32) and ACTH<1 ng/l). Cerebral CT performed showed left posterior temporal calcified lesion, placing the hypothesis of meningioma.

Conclusion: Genotyping of ARMC5 gene has important clinical implications in counseling the patient and family: the presence of the mutation helps identify patients at risk of developing CS and other related injuries, allowing early diagnosis and treatment. There are cases described of CS remission after unilateral adrenalectomy, so we opted for medical surveillance of the patient.