Aldosterone-Producing Adenoma Hidden behind Chronic Renal Failure with Nephrotic Syndrome
Presentation Number: SAT 378
Date of Presentation: April 1st, 2017
Yuta Tezuka*1, Ryo Morimoto1, Yoshikiyo Ono2, Yoshitsugu Iwakura3, Masataka Kudo1, Yasuhiro Igarashi1, Mariko Miyazaki4, Hiroshi Sato4, Kazumasa Seiji1, Kei Takase1, Yoichi Arai1, Yuto Yamazaki5, Yasuhiro Nakamura6, Hironobu Sasano5, Sadayoshi Ito1 and Fumitoshi Satoh5
1Tohoku University Hospital, Sendai, Japan, 2Tohoku Uiversity Hospital, Sendai, Japan, 3Tohoku Medical and Pharmaceutical University Hospital, Sendai, Japan, 4Tohoku University Hospital, 5Tohoku University Graduate School of Medicine, Sendai, Japan, 6Tohoku Medical and Pharmaceutical University, Sendai, Japan
[Introduction] Primary aldosteronism (PA) is characterized by low plasma renin activity (PRA) suppressed by high plasma aldosterone concentration (PAC). However, in some cases with nephropathy developed by PA or other causes, PRA can be elevated that makes the diagnosis of PA, especially Aldosterone-Producing Adenoma (APA), more difficult. [Case report] A 59-year-old man was referred to our hospital due to a right adrenal tumor with hypokalemia. He also had difficult-to-control hypertension treated with five anti-hypertensive agents and chronic renal failure (CRF) accompanied with nephrotic-range proteinuria, 5.3 g/gCr. With the medications including β blocker, aldosterone-to-renin ratio (ARR) was 68.2 ng/dL per ng/mL/hr so that PA was suspected. Clinical parameters at the first visit were as follows; body mass index 28.8; blood pressure 135/74 mmHg; heart rate 61 bpm; serum pottasium 2.8 mM; serum albumin 2.5g/dL; estimated GFR 20.8 mL/min/1.73m2. However, PAC and PRA were decreased to 29.4 ng/dL and increased to 2.2 ng/mL/hr, respectively, that resulted in low ARR, 13.4, after discontinuing β blocker. PRA fluctuated between 1.0 and 2.8 ng/mL/hr. Although it seemed to secondary hyperaldosteronism (SHA), PAC remained around 30 ng/dL during 50 mg captopril challenge test (CCT). Above results suggested the probability of coexistence of autonomous aldosterone hypersecretion (AAH) and SHA. In order to confirm the existence and determine the laterality of AAH, we decided to perform adrenal venous sampling (AVS). Because of CRF, we used non-contrast-enhanced magnetic resonance venography to map adrenal veins prior to AVS. After mapping, cosyntropin-stimulated AVS was performed with carbon dioxide and only 8 mL of contrast material by skilled angiographers. As a result, aldosterone-to-cortisol ratio in right adrenal venous sample was 12.8 times higher than that in left adrenal venous sample. Accordingly, we diagnosed him with AAH from right adrenal gland which harbored a tumor, complicated with SHA due to CRF. In preparation for laparoscopic right adrenalectomy, angiotensin II receptor blocker and mineralocorticoid receptor antagonist were started and gradually increased to reduce proteinuria. Finally, we achieved a 90% reduction in proteinuria with 30 mg of azilsartan and 90 mg of spironolactone without exacerbation of CRF. And then, he underwent laparoscopic right adrenalectomy. The removed adrenal gland had an adrenocortical tumor which was classified into benign adenoma based on Weiss's criteria. In immunohistochemical staining, the adrenocortical adenoma showed diffuse expression of CYP11B2, indicating that the adenoma was an APA. After operation, his blood pressure and proteinuria were improved. [Conclusion] We experienced a suggestive case of APA which showed normal PRA due to CRF. In cases with decreased renal function, CCT and AVS, not ARR, may be useful to evaluate AAH.
Nothing to Disclose: YT, RM, YO, YI, MK, YI, MM, HS, KS, KT, YA, YY, YN, HS, SI, FS