Abstract
INTRODUCTION: Congenital renal arteriovenous malformations are abnormal communications between the intrarenal venous and arterial systems. An unusual cause of massive gross hematuria and an even rarer cause of hemodynamically significant anemia, its presentation remains variable from incidental imaging findings to severe hypertension and congestive heart failure. CASE PRESENTATION: We present a case of a 44-year-old Chinese man with no personal or familial history of bleeding diasthesis that presented with gross hematuria leading to clot retention after routine physical activity. CONCLUSIONS: We have presented this case in an effort to highlight the possibility of this entity as a cause of acute upper urinary tract hemorrhage and the need for a computed tomography angiogram to clinch the diagnosis.