Massive secretions in paragonimiasis pleural effusion: a new finding concerning clinical recognition and treatment

Some paragonimiasis patients in Chongqing, southwest China, have recently exhibited pleural effusions (PEs) with massive viscous secretions. This study aimed to investigate their clinical characteristics, thereby promoting effective treatments. A 3-year retrospective review of paragonimiasis patients who were admitted for nonhomogeneous PEs at Chongqing University Three Gorges Hospital was conducted. Epidemiological data, symptoms, laboratory and imaging findings, treatments, and outcomes were analyzed. Twenty-eight patients were identified, of which 22 (78.6%) were males and 22 (78.6%) were rural residents. Respiratory (85.7%) and constitutional (57.1%) symptoms were common. Paragonimus-specific ELISA was positive in all patients. Eosinophilia was detected in all patients in peripheral blood and PEs. Irregular hyperdense signals were observed in PEs by chest CT scans (96.4%) and ultrasonography (100.0%). Thoracic closed drainage failed in 10 patients (conservative group) because of tube blockage and was eventually replaced by video-assisted thoracoscopic surgery (VATS). Eighteen patients (surgery group) initially underwent VATS, or thoracotomy surgery, without complications. Massive secretions, described as "bean-dregs" or "egg-floccule," were detected intraoperatively, which explained the imaging findings and tube blockage. All patients recovered well after 2-3 courses of postoperative praziquantel treatment. Viscous secretions in paragonimiasis patients warrant great concern. Irregular hyperdense signals in effusions are important characteristics in CT scans and ultrasonography. Treatments such as thoracic closed drainage may fail due to viscous secretions blocking the tube; therefore, surgeries should be considered. In-depth multidisciplinary research may help determine the optimal treatment strategy and reveal the origin of these secretions.