Een 30-jarige man met een plas pleuravocht

Patrick F. Greve en Gijs J.M. Limonard

A 30-year-old man with a puddle of pleural effusion


The pleural effusion found in urinothorax is traditionally classified as transudate. In some cases, however, the Light-criteria can show an exudate.

Case description

We describe the case of a 30-year-old man who attended the emergency department with shortness of breath and severe, diffuse, chest pain; this occurred two days after he had undergone a left-sided percutaneous nephrolithotomy by a urologist. A chest X-ray showed pleural effusion in the left basal region. Based on the Light-criteria, this effusion was an exudate. We made the diagnosis of urinothorax following percutaneous nephrolithotomy.


When urinothorax is suspected, biochemical analysis can reveal either a transudate or an exudate. The pleural fluid/serum creatinine ratio can be a valuable addition to the Light-criteria in this setting. The Light-criteria should always be interpreted in a clinical context.

Conflict of interest and financial support: none declared.