Multiple serous membrane effusion caused by primary pericardial mesothelioma

Primary pericardial mesothelioma is an extremely rare cancer with a short survival prognosis. Clinical symptoms are often atypical, and most patients are diagnosed after surgery or at autopsy. We report a case of a 35-year-old female patient with multiple serous membrane effusion for more than 1 year. The patient underwent pericardial, pleural, and peritoneal fluid drainage many times and underwent many laboratory tests to find the cause; however, there was no definitive diagnosis. She was admitted to the hospital because of shortness of breath, cough, and sputum for 5 days. She underwent extensive pericardiectomy to resolve the dyspnea and pericardial surgery to find the cause of the multiple serous membrane effusion. After surgery, her dyspnea was relieved, and the serous effusion gradually decreased.