Endocrine Abstracts

Introduction: Primary bilateral macronodular adrenal hyperplasia (PBMAH) is a rare entity. Up to 1/3 of patients with incidental bilateral adrenal nodules presents biochemical evidence of hypercortisolism responsible for obesity, diabetes mellitus (DM), arterial hypertension or dyslipidemia. Its insidious course and nonspecific signs explain the underdiagnosis of this entity.

Objective: To describe the case of a patient with metabolic syndrome (MS) with hypercortisolism and diagnosis of PBMAH and its evolution after unilateral adrenalectomy.

Clinical Case: A 73-year-old man was referred to an Endocrinology consultation in 2013 due to incidental bilateral adrenal nodules detected in a vascular study. It is a patient with DM diagnosed at 52 years old without insulin therapy and HbA1c of 6.4%, class II obesity (weight 103 kg, Body Mass Index 36.1 kg/m²), high blood pressure under 4 classes of antihypertensive drugs and mixed dyslipidemia. He presented a serum cortisol level post-1 mg dexamethasone suppression test and post-low dose dexamethasone suppression test of 2.70 and 2.60 μg/dl, respectively, and an aldosterone at 4 h after saline suppression test of 7 ng/dl. The urinary free cortisol measurement was 27.0 and 40.3 µg/24 h (4.3-176.0), serum cortisol (8 h) 12.50 μg/dl (4.82-19.50), ACTH (8 h) 6.61 pg/ml (ND-46) and DHEA-SO4 97 μg/dl (104.9-256.1). He performed a non-radiocontrast-enhanced computed tomography that showed a nodular thickening of the right adrenal with 24 mm and of the left adrenal with 20 mm. He maintained medical treatment due to clinical stability. In 2016 due to worsening of glycemic control, he needed insulin therapy in increasing doses (maximum 96 U/day) with a maximum HbA1c of 9.8% in December 2020. He was proposed for surgery and performed a scintigraphy of the adrenal cortex with 131 I-norcholesterol, which showed bilateral adrenal cortex hyperfunction. In 2021, he underwent right adrenalectomy with histological examination compatible with PBMAH. Three months after surgery he improved his glycemic profile (HbA1c 6.4%) and he had a 16.7% reduction in total daily dose (TDD) of insulin (80 U/day), maintaining his weight (103 kg) and his antihypertensive therapy.

Conclusion: In this clinical report, PBMAH seems to have contributed to MS previously known and the worsening of DM which is reinforced by the reduction of TDD of insulin after unilateral adrenalectomy. Considering the potential for improvement of comorbidities after surgery, there should be a high index of suspicion in the presence of MS and bilateral adrenal nodules.