Adenocarcinoma on horseshoe kidney studied with computed tomography.

Horseshoe kidney is a congenital anomaly of the upper urinary system frequently associated with atypical vascularization, mostly asymptomatic, usually undetected until the onset of infectious, obstructive or neoplastic complications. Although intravenous pyelography and US are useful tools, the role of CT is of vital importance especially in the pre-operative planning of related complications and in those cases where other techniques have correctly diagnosed the disease but have missed the visualization of an underlying malformation. We report here two cases of adenocarcinoma in two patients with a horseshoe kidney, where CT has clearly depicted both the malformation and the associated pathologic findings.