Uriniferous pseudocyst: computed tomographic findings.

The computed tomographic (CT) scans of nine consecutive patients with proved uriniferous pseudocyst (UP) were analyzed retrospectively. Analysis disclosed perirenal space tumefaction in seven patients, tumefaction outside the perirenal space in two patients, cystlike uniformity of attenuation (with specific exceptions) in all nine patients, contrast medium-opacified urine extravasating into the UP in three patients, contrast material within the dependent portion of the UP in one patient, anterior and superior displacement of the kidney in seven patients, hydronephrosis in all nine patients, and associated findings suggesting the underlying cause of UP in five patients. Although these CT findings appear to be quite specific, consideration of this uncommon entity in the CT differential diagnosis requires knowledge of its reported causes, the patient's medical history, and the clinical presentation.