Metastatic synovial sarcoma of lung mimicking pulmonary embolism and deep venous thrombosis

Synovial sarcoma (SS) is a highly aggressive mesenchymal malignancy that usually originates from deep soft tissues of the extremities. Lungs are the most common metastatic site, but rare cases of vascular metastasis have been reported. Here we report a case of metastatic SS in a 26-year-old male patient with right lower extremity oedema first misdiagnosed as deep venous thrombosis (DVT). CT pulmonary angiogram (CTPA) revealed a mass lesion inside the right pulmonary artery mimicking PE. The diagnosis of SS was established by histopathological examination acquired by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) from the right pulmonary artery. 18FDG-PET revealed that breviductor and pectineus muscle was the original site of SS with metastasis in common and external iliac veins, pulmonary artery and pulmonary parenchyma. A 26-year-old man presented to our hospital with repeated right leg swelling and chest pain. Nine months before hospitalisation, the patient had right leg swelling and was diagnosed with DVT according to an ultrasound scan. Catheter-directed thrombolysis was performed followed by anticoagulation. The patient had slight relief in symptoms. Seven months later he had intermittent chest pain. …