Urinothorax: A Rare Cause of Pleural Effusion

Urinothorax is a rare cause of pleural effusion, which is seen in patients with obstructive uropathy, blunt trauma, or ureteric injury during abdominal surgical procedures. Clinical symptoms may include dyspnea, chest pain, cough, fever, abdominal pain, and decreased urine output. Diagnosis is made by thoracentesis, which would reveal fluid with a urine-like odor, and pleural fluid analysis, which would show if fluid is transudative in nature with a pH lower than 7.30. Pleural fluid to serum creatine ratio of more than 1 is diagnostic for this condition. In our case, the patient underwent percutaneous nephrolithotripsy with a stent placement three days before presentation to the hospital. She was diagnosed with urinothorax, which led to further investigations, and she was found to have persistent hydronephrosis. Her condition improved after her underlying hydronephrosis was addressed with stent placement. She was discharged home in stable condition.