We sometimes experience a case of aldosterone-producing adenoma (APA) without a sign of overproduction of aldosterone in adrenal venous sampling (AVS). One of the reasons is that APA can form ectopic drainage veins besides the authentic adrenal central veins. We tried to utilize computed tomography (CT) during arteriography for identification of such drainage veins in a case of APA.Design and method:
A 56-year-old Japanese male was treated for hypertension with amlodipine (5 mg/day) for the past 6 years. In April 2015, primary aldosteronism (PA) was suspected because a laboratory examination showed hypokalemia (2.6 mEq/L). Endocrinological evaluations indicated hyperaldosteronism with high aldosterone renin ratio (ARR): plasma aldosterone concentration (PAC) 272 pg/ml, plasma renin activity (PRA) 0.2 ng/ml/hr and ARR 1360. Abdominal CT suggested APA of 8 mm in diameter at the left adrenal gland. AVS was performed to confirm overproduction of aldosterone from APA; however, the overproduction was not identified in both sides of adrenal central veins, in spite of successful cannulation. We performed CT during arteriography to identify outflow from the adenoma in consideration of ectopic drainage veins.Results:
The left renal capsular vein and a small branch to the left renal vein were clearly visualized as drainage veins from the adenoma. AVS was again conducted from these drainage veins and we successfully confirmed overproduction of aldosterone from them. He was diagnosed as left APA and laparoscopic adrenalectomy was performed. After the operation, the blood levels of PAC and PRA became normal and his blood pressure and hypokalemia also normalized.Conclusions:
There are several reports that demonstrate ectopic drainage veins from adrenal adenoma (JAMA Surg. 148:378, 2013). Identification of aldosterone overproduction in APA with ectopic drainage veins is not easy for conventional AVS procedure. CT during arteriography is indicated to be useful for identification of ectopic drainage veins in such case of APA.