A Rare Case of Urinothorax Due to Spontaneous Renal Calyx Rupture

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Pleural effusion of extra-vascular origin (PEEVO) occurs when fluid from an extrapleural space migrates to the pleural cavity. This fluid can originate from the genitourinary tract, abdomen, central nervous system, or the biliary tract. Transudative effusions of extra-vascular origin consist of fluid which contains urine, peritoneal dialysate, central venous catheter infusate, cerebrospinal fluid or glycinothorax seen as complication from transurethral surgery. Described below is a rare case of a urinothorax due to spontaneous renal calyx rupture.
Case Description:
An 80-year-old male with a remote history of bladder cancer presented to emergency department with several days of shortness of breath. He was noted to be hypoxic and in moderate respiratory distress on physical exam. Computed Tomography (CT) of the chest revealed a left-sided pleural effusion and retroperitoneal fluid in the upper abdomen; he was given diuretics and antibiotics for community-acquired pneumonia and transferred to our institution. Subsequent CT angiogram of the abdomen showed bilateral hydronephrosis with left sided perinephric stranding and fluid likely secondary to calyx rupture. He subsequently underwent left-sided thoracentesis that yielded 1.8 liters of serosanguinous fluid. Fluid studies revealed a pH of 8.12, lactate dehydrogenase of 239, glucose of 115, and pleural fluid-to-serum creatinine ratio of 1.15, leading to a diagnosis of urinothorax secondary to a forniceal rupture.
Urinothorax, or the presence of urine in the pleural space, is a very unusual cause of pleural effusion. The mechanism behind this condition involves the leakage of urine into the retroperitoneal space, which then migrates to the pleural space via diaphragmatic lymphatics and/or anatomical defects in the diaphragm. Urionthoraces can further be classified into obstructive (caused by obstructive uropathies) or traumatic in origin. To our knowledge, urinothorax due to spontaneous renal calyx rupture has rarely been reported. These effusions are typically transudative and exhibit a low pH; however, this is not true in all cases. The diagnosis can ultimately be confirmed by a pleural fluid-to-serum creatinine ratio greater than one and is effectively treated with adequate drainage of the pleural space and correction of the underlying urologic pathology.


Medicine and Health Sciences


Department of Medicine, Department of Medicine Faculty, Department of Medicine Fellows and Residents, Fellows and Residents, Department of Emergency Medicine, Department of Emergency Medicine Residents

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