LBSAT61 Pure Aldosterone-secreting Adrenocortical Carcinoma Causing Resistant Hypertension In A Patient With Previously Controlled Longstanding Hypertension: A Case Report

INTRODUCTION: Adrenocortical carcinoma is a rare endocrine malignancy that could be classified into functioning or non-functioning, depending on the tumor's ability to secret adrenocortical hormones. Pure aldosterone-secreting adrenocortical carcinoma is extremely rare, accounting for <7% of all functioning tumors that could present with primary aldosteronism and secondary hypertension. CASE PRESENTATION: A 48-year-old man had a past medical history of longstanding hypertension that recently became resistant to multiple antihypertensive medications (thiazide, angiotensin receptor inhibitor, calcium channel blocker, hydralazine) despite medications compliance. He presented to the ER with left flank pain that was not associated with dysuria, nausea, or vomiting. On admission, his blood pressure was 223/135 mmHg. CT scan of the abdomen and pelvis showed mild left-sided hydronephrosis, hydroureter with a 2mm stone at the left ureterovesical junction, and a 7. 0×7. 0×6.4 cm left heterogeneous adrenal mass that was highly suspicious for malignancy. His laboratory workup revealed low serum potassium of 2.9 mmol/L (reference value 3.5-5.1 mmol/L), serum creatinine of 1.38 mg/dL (reference value 0.7-1.3 mg/dL), random cortisol of 21.8 mcg/dL (reference value 5-25 mcg/dL), ACTH of 5 pmol/L (reference value 10-60 pmol/L), serum levels of normetanephrine of 0.67 nmol/L (reference range 0-0.89 nmol/L), metanephrines of <0.10 nmol/L (reference range 0-0.49 nmol/L), and chromogranin A of 45 ng/mL (reference range 0-95 ng/mL). Further investigations showed high serum aldosterone of 28 ng/dL (reference range 2-9 ng/dL) and low plasma renin activity of 0.1 ng/mL per h (reference range 0.5-2.5 ng/mL per h) supported the diagnosis of primary aldosteronism. The patient underwent left adrenalectomy, and the diagnosis of pure aldosterone-secreting adrenocortical carcinoma was confirmed by histological examination. CONCLUSION: Pure aldosterone-secreting adrenocortical carcinoma is an extremely rare adrenal tumor that could cause resistant hypertension. Re-evaluation of secondary causes of hypertension is essential in patients with a previously controlled longstanding hypertension, developing uncontrolled or resistant hypertension. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.