Spindle cell sarcoma of the right atrium causing right atrial pseudoaneurysm: a case report and review of the literature

Background: Spindle cell sarcomas of the right atrium are extremely rare primary cardiac tumours, with very few cases reported in the medical literature. Pseudoaneurysms caused by cardiac spindle cell sarcoma have never been reported worldwide. Case presentation: A 32-year-old woman was referred to our hospital for recurrent pericardial haemorrhagic effusion and pleural effusion. Three-dimensional transthoracic echocardiogram, contrast chest CT, and contrast MRI revealed a pseudoaneurysm on the right side of the right atrium with a thrombus. There was a defect between the pseudoaneurysm and the right atrium. PET-CT suggested that FDG metabolism inhomogeneity increased in the mass in the right atrium. Exfoliative cytology detection of massive pericardial effusion and pleural effusion revealed no tumour cells. Spindle cell sarcoma of the right atrium was not confirmed until the patient underwent right thoracic exploration and biopsy. Before a confirmed diagnosis, symptomatic treatment, such as chest effusion and pericardium effusion drainage, and transfusion of red blood cells were mainly used to relieve the patient's symptoms. Unfortunately, the patient was lost to optimal treatments and passed away 20days after the pathological diagnosis was made. Conclusion: The prognosis of spindle cell sarcomas remains poor due to delays in diagnosis, early metastasis and few available therapeutic options. Recurrent pericardial effusion and pleural effusion, especially in the nature of haemorrhagic effusion, and/or right atrial pseudoaneurysm shown on the transthoracic echocardiogram must be considered and highly suspected as malignancy by patients and physicians. If the diagnosis cannot be confirmed, histopathology should be performed as soon as possible to avoid losing the best treatment opportunity.