SAT-073 A Case of Williams Syndrome Associated with Aldosterone Producing Adrenal Adenoma Mimicking Hepatic Adrenal Rest Tumor

Background: Williams syndrome (WS) is a microdeletion disorder caused by heterozygous loss of approximately 1.5-Mb pairs of DNA from chromosome 7. Patients with WS have a characteristic constellation of medical and cognitive findings, with a hallmark feature of generalized arteriopathy presenting as stenoses of elastic arteries and hypertension. We present here a case of WS associated with primary aldosteronism (PA), whose source of aldosterone excess was difficult to locate. Clinical case: A 31-year-old man suspected having PA was referred to our Hospital. He was diagnosed as having Williams syndrome at 2 months of age. He had been hypertensive for 9 years. At the age of 31 years old, low serum potassium (K) and high aldosterone to renin ratio were pointed out. His plasma renin activity (PRA) was 0.2 ng/ml/h, plasma aldosterone concentration (PAC) was 456 pg/ml, serum K level was 3.1 mEq/l at admission. Diagnosis of PA was confirmed according to positive captopril challenge test. CT scan revealed a 13mm tumor with low density in posterosuperior segment of right hepatic lobe, but adrenal tumor was not detected. Venography of adrenal vein sampling (AVS) showed an extended tributary of the right adrenal vein to the liver that surrounded the tumor. Segmental AVS was performed for right adrenal vein and showed a high value of PAC (377000 pg/ml) in superior tributary which was drained from the tumor. PAC in other tributaries of right adrenal vein and left adrenal vein was suppressed. Laparoscopic partial hepatectomy was performed as a liver tumor. After surgery, serum K level was normalized, PAC decreased to 67 pg/ml. Pathological examination revealed a golden-yellow tumor separated from the liver by fibrous septum. The tumor was attached to an adrenal cortex embedded in the liver. The tumor was composed of clear cells, positive for 3βHSD2 and CYP11B2 using immunohistochemistry, diagnosed as aldosterone producing adrenal adenoma. Conclusion: To the best of our knowledge, this is the first report of WS associated with PA. Since WS is a disease with high prevalence of hypertension, measurement of PRA and PAC for screening of PA is recommended for patients with WS associated with hypertension. According to CT findings, hepatic adrenal rest tumor was suspected because the tumor was not continuous with the right adrenal gland, but pathological findings demonstrated that an adrenal adenoma was originated from right adrenal cortex rather embedded in the liver. Segmental AVS was useful to distinguish adrenal tumor from hepatic adrenal rest tumor.