Atypical Adrenocortical Incidentaloma Causing Autonomous Cortisol Secretion and Cardiovascular Complications

Abstract

Introduction: Autonomous cortisol secretion (ACS) is found in approximately 10% of patients with an adrenocortical incidentaloma (AI). The majority of these cases are due to non-ACTH-dependent ACS. 2% of patients with AI have adrenocortical cancer. ACS is associated with cardiovascular morbidity, includes arterial stiffness, hypertension, coronary heart disease, and fatal or nonfatal myocardial infarction. Case presentation: A 62-year-old Caucasian male with a history of hypertension (HTN), hyperlipidemia (HLD) and poorly controlled type-2 diabetes mellitus (T2DM) and a recent myocardial infarction (MI) status post (s/p) coronary artery bypass graft (CABG) who presented to the endocrine clinic for evaluation of left adrenal mass. Family history was significant for adrenal carcinoma of his brother at the age of 60. The patient denied any facial flushing, palpitations, tremors, heat or cold intolerance, abnormal sweating, diarrhea, constipation, abdominal pain, recent weight change. Physical examination was unremarkable except midline sternal scar s/p CABG. Vital signs were remarkable for a blood pressure of 142/90. Labs were unremarkable. CT adrenal revealed a left adrenal mass 4.9 x 3.5 x 2.3 cm with HU -3 to 28 heterogeneous. HbA 1C was 8.2 %. Adrenal incidentaloma workup revealed a normal 24-hour urine cortisol level of 29 mcg, abnormal mid-night salivary cortisol of 0.13 mcg/dL and 0.31 mcg/dL, elevated cortisol after 1 mg dexamethasone suppression test (DST) of 343 mcg/dL, elevated cortisol after 8 mg DST of 90 mcg/dL, normal metanephrines of 10 pg/mL and normal normetanephrine of 49 pg/mL, normal aldosterone of 6.1 ng/dL, normal renin activity of 0.36 ng/ml/hr (Aldo/ PRA ratio 16). ACTH was 4.5 pg/ml. The endocrine surgeon was consulted for left adrenalectomy. The pathology showed atypical adrenal cortical neoplasm which does not clearly fulfill the criteria for adrenal cortical carcinoma confirmed by two pathologists. Upon six months follow-up, a 24-hour urine cortisol level was normal, 1mg overnight DST was normal, and no evidence of left adrenal on adrenal CT. Discussion: Adrenal incidentaloma (AI) is a common endocrine diagnosis affecting ~2% of the general population. Up to 10% of patients with AI have autonomous secretion of adrenal hormones. Pheochromocytoma and autonomous cortisol secretion should be excluded in every case and aldosteronism in patients with underlying hypertension and/or hypokalemia. ACS in patients AI has been associated with hypertension, insulin resistance, type 2 diabetes mellitus, obesity, metabolic syndrome, coronary artery disease, and increased mortality. Adrenalectomy is recommended for patients with a functional unilateral adenoma, with clinically significant hormone excess. Metabolic improvement after adrenalectomy, including weight loss, blood pressure lowering, glucose tolerance, lower lipids have been reported.