Abstract 12450: Mystifying Masquerade: Renal Cell Carcinoma Associated Arteriovenous Fistula Presenting as High-Output Heart Failure

Abstract

Case Presentation: 59 year-old woman with CKD stage 3b and hypertension presented with 3 months of progressive dyspnea, abdominal distension, bilateral lower extremity edema, and a 60-pound weight gain. Physical exam noted diffuse anasarca, with stable hemodynamics on room air. EKG revealed low voltage leads and chest X-ray demonstrated an enlarged cardiac silhouette. CT abdomen was remarkable for significant ascites, body wall edema, and a suspicious large right renal mass. Diagnostic paracentesis indicated cardiac ascites. Echocardiogram showed preserved ejection fraction, moderate pericardial effusion and an enlarged right side of the heart. Right heart catheterization confirmed high-output heart failure (HOHF). A suspected renal mass-related arteriovenous fistula (AVF) was confirmed through inferior vena caval and renal venogram blood gas sampling, indicating arteriovenous shunting within the renal mass. Hepatic venogram excluded portal hypertension. MRI abdomen confirmed a large necrotic right renal mass consistent with renal cell carcinoma (RCC). Symptoms significantly improved after nephrectomy, with aggressive diuresis, and therapeutic paracenteses leading to an 80-pound weight loss. Postoperative echocardiography illustrated decrease in pericardial effusion and right ventricular size. Cardiac MRI and stress test were unremarkable prior to planned immunotherapy for stage III RCC. Discussion: AVF and HOHF associated with malignancy are unusual presentations. RCC is the most prevalent underlying malignancy linked with AVF and is hypothesized to be a result of hypervascularity caused by a VHL gene mutation. The most often utilized imaging modalities for detecting a tumor-related AVF are contrast enhanced CT or MRI. When imaging is inconclusive, a venogram with blood gas sample, as observed in our case, may be considered to establish an RCC-associated AVF.