Recurrent Cardiac Tamponade by Pulmonary Artery Intimal Sarcoma.

A 43-year-old woman presented with dyspnea and cough, initially misdiagnosed as respiratory syncytial virus. Persistent symptoms led to pulmonary thromboembolism treatment, but worsening issues revealed recurrent pericardial effusion. Imaging and biopsy confirmed pulmonary artery intimal sarcoma, mimicking thromboembolism, and autoimmune disease, underscoring diagnostic challenges. Contrast-enhanced angiotomography showing filling defects suggestive of pulmonary thromboembolism. Echocardiogram with severe pericardial effusion. T2-weighted MRI with two heterogeneous masses on the right side and another adjacent to the left atrium. Biopsy confirming pulmonary artery intimal sarcoma.