[Urine in the wrong place: urothorax].

Considering the only 38 cases which have been published one may believe that the accumulation of urine in the thorax would be a very uncommon cause of pleural effusion. But the lack of reported observations could also reflect a lack of suspicion. A leakage of the urinary tract following obstruction of various origins and/or a local trauma is known as urinoma. Due to excess pressure, this retroperitoneal or intraperitoneal collection of urine gives way to a transdiaphragmatic evasion. Therefore, a concomitant ipsilateral or bilateral pleural effusion should be suspicious of urinothorax. Thoracocentesis, followed by measurement of creatinine in the pleural fluid, is a simple procedure to establish the true diagnosis. This is a report of two patients with urinothorax, resulting from uterine and prostatic adenocarcinoma. In the first case, urine passed through a leakage of the bladder into the peritoneal cavity; in the second case, there was hydronephrosis with pelvic disruption.