O-07 CORTISOL-SECRETING ONCOCYTIC ADRENOCORTICAL NEOPLASM PRESENTING WITH HYPERTENSION AND HYPOKALAEMIA

Abstract Introduction Oncocytic adrenocortical neoplasms (OANs) are rare. They are usually asymptomatic, benign and non-functional. Histologically, they display large polygonal cells with granular and eosinophilic cytoplasm. We report a case of left benign cortisol-secreting OAN with initial presentation of hypertension and hypokalaemia. Clinical Case A 46-year-old Asian female with a 10-year history of hypertension and hypokalemia was referred to our clinic for evaluation. She was taking potassium supplement and multiple anti-hypertensives. On physical examination, blood pressure was 141/69 mmHg, BMI 30.9 kg/m². She had facial plethora. There were no abdominal striae, easy bruising, or proximal myopathy. Her serum potassium level was 2.8 mmol/L (3.5-4.5), am cortisol 221 nmol/L (101-536), aldosterone/renin ratio 77 (< 550). Laboratory parameters are summarized in Table 1. A CT urogram was later done during an admission for pyelonephritis, revealing a 2.8 cm left adrenal nodule over lateral limb (Figure 1). The pre-contrast attenuation was 20 Hounsfield units (HU). There were no macroscopic fat or calcifications. Hormonal studies revealed normal 24-hour urine free metanephrines (Table 2). Her ACTH level was 1.7 pmol/L (