Case of urinothorax – A rare presentation

Urinothorax (UT) is a rare and often undiagnosed condition, defined as the presence of urine in the pleural cavity due to the retroperitoneal leakage of urine (known as urinoma) into the pleural space. It is a rare cause of pleural effusion and is secondary to traumatic or obstructive reasons. UT is usually a transudate pleural effusion. Its diagnosis requires a high degree of clinical suspicion, because the respiratory symptoms tend to be absent or mild and urological signs tend to dominate. Thoracocentesis followed by measurement of creatinine in the pleural fluid is a procedure to establish the true diagnosis. The average pleural fluid-to-serum creatinine ratio is in the range of 1.09–19.8. Pleural fluid-to-serum creatinine ratio >1 is the diagnostic criterion of UT. We report a case of UT associated with trauma.