Abstract
A 52-year-old gentleman presented with symptoms of breathlessness and type 1 respiratory failure. His CT pulmonary angiogram showed a heterogenous, oval-shaped lesion between the heart and diaphragm with a right atrial (RA) filling defect, pericardial thickening and pulmonary metastasis. An RA debulking salvage operation confirmed this to be a pericardial tumour and further cytology and immunohistochemistry testing confirmed a primary synovial sarcoma. After 12 days in intensive care for ventilation, the patient was successfully discharged on warfarin and underwent oncology follow-up for chemotherapy. Following a 15-month follow-up, no mortality was observed despite the aggressive nature of the tumour.