Urinothorax - A Rare Cause of Pleural Effusion.

Urinothorax is a rare cause of pleural effusion, which is mostly seen secondary to obstructive uropathy. We report a patient who had nephrolithasis and underwent percutaneous nephrostomy for treatment of hydroureteronephrosis. The patient developed right-sided pleural effusion, five days after percutaneous nephrostomy, which was later diagnosed as urinothorax. Although rare, urinothorax should be considered in the differential diagnosis of causes of pleural effusion, especially in patients with obstructive uropathy, any form of instrumentation of urinary tract or blunt abdominal trauma.The importance of recognizing this entity lies in the fact that the condition is completely reversible following relief of urinary tract obstruction.