Synovial sarcoma invades the left atrium: visualization with three-dimensional trans-oesophageal echocardiography

A 36-year-old male presented with right hemiplegia and aphasia. Computed tomography imaging showed showered infarcts with multi-organ involvement including left carotid filling defect and left upper lung mass encasing the left upper pulmonary vein (Panels A and B). Trans-thoracic echocardiogram revealed a left atrial mass oscillating into the left ventricle. Two-dimensional trans-oesophageal echocardiogram (TEE) demonstrated a large mass originating from the left upper pulmonary vein going into the left atrium and left ventricle (Panels C and D; Supplementary data online, Videos S1 and S2). Three-dimensional (3D) TEE revealed relative anatomy of surrounding structures, including left atrial appendage, septum and tricuspid valve in greater detail. Panel E and Supplementary data online, Video S3 are a view of the tumour projecting outward from the left upper pulmonary vein while oscillating into the left ventricle, previously only viewable in the operating theatre by the surgeon. Core biopsies obtained from the mass illustrated highly mitotic spindles consistent with synovial sarcoma (Panel F, top arrow) with interspersed capillaries (Panel F, bottom arrow). Diagnosis was confirmed using fluorescence in situ hybridization demonstrating translocation t(X,18), seen in synovial carcinoma. There are no previous case reports of synovial sarcoma invading into the heart visualized with 3D TEE. Synovial sarcoma is a rare, aggressive, malignant tumour accounting for nearly 14% of all sarcomas with origination from lung or pleura. This case demonstrates the unique ability of 3D TEE in visualization of the tumour originating from the left upper pulmonary vein in a fashion otherwise available only to the surgeon in the operating theatre. Supplementary data are available at European Heart Journal – Cardiovascular Imaging online.