Primary pulmonary monophasic synovial sarcoma initially presenting with bloody pleural effusion: A case report and literature review

Key Clinical Message Primary pulmonary synovial sarcoma (PPSS) can originate from blood vessels of the bronchial wall, lung interstitium, and interstitial components, and accounts for 0.1%–0.5% of all primary lung malignancies, the most common symptoms are chest pain, cough, dyspnea, and hemoptysis. Abstract Synovial sarcoma (SS) is a rare malignant tumor of stromal origin, which accounts for approximately 8%–10% of all soft tissue sarcomas. Primary pulmonary synovial sarcoma (PPSS) can originate from blood vessels of the bronchial wall, lung interstitium, and interstitial components, and accounts for 0.1%–0.5% of all primary lung malignancies. Patient concerns: We report the first case of a 57‐year‐old man with bloody pleural effusion as an initial manifestation of PPSS in the middle lobe of the right lung diagnosed after surgery. Diagnosis: Chest computed tomography (CT) revealed a mass in the middle lobe of the right lung, which was pathologically diagnosed as a monophasic SS after surgical resection. Interventions: Ten days after preoperative closed chest drainage, a right thoracotomy was performed to remove the right middle lobe of the lung. Outcomes: The patient recovered smoothly and was discharged from the hospital without any other postoperative treatment. A follow‐up chest CT scan 7 months postoperatively revealed intrapulmonary recurrence with multiple metastases. Lessons: Monophasic PPSS of the lung may present with bloody pleural effusion as its first manifestation.