[Renal cirsoid aneurysm (congenital arteriovenous fistula): a rare cause of severe hematuria].

Objective: Congenital arteriovenous fistulas are an exceptional clinical feature. Although they are frequently asymptomatic, their presentation as severe hematuria pose an excellent diagnostic exercise and often immediate therapeutic action.
Methods/results: We report the case of a 75-year-old female patient presenting with severe hematuria producing anaemia, high blood pressure and congestive heart failure. Image tests revealed right ureteral-hydronephrosis with bladder blockage by blood clots. The endoscopic study (cystoscopy and ureterorenoscopy) alerted about the origin of the hematuria from the right kidney, finally requiring nephrectomy as definitive treatment. Pathology revealed the presence of a round formation with multiple vascular channels, arterial and venous, in the pyelocalicial submucosa, with focal epithelial erosion, compatible with congenital arteriovenous fistula. We review the diagnostic and therapeutic features in the literature.
Conclusions: Renal congenital arteriovenous fistulas represent a diagnostic dilemma. They may present asymptomatic or condition clinical features derived from the shunt and high cardiac output (hypertensive cardiopathy and congestive heart failure) or from the erosion and acute hemorrhage into the urinary tract (severe renal hematuria). Treatment should be conservative with embolization or supraselective sclerosis. Nevertheless, in cases of big fistulas, post embolization revascularization, or hemodynamic instability nephrectomy is an excellent option.