A 43-year-old woman with no prior medical issues presented with dyspnea and cough, initially diagnosed as RSV infection. Persistent symptoms led to a diagnosis of pulmonary thromboembolism, treated with EKOS thrombectomy and anticoagulation. Despite two thrombectomies, she had worsening symptoms, dyspnea, and pleuritic pain, with recurrent pericardial effusion. Lab results indicated possible lupus or antiphospholipid syndrome. Echocardiography and imaging revealed pericardial effusion and pulmonary lesions. Biopsies confirmed pulmonary artery intimal sarcoma. Post-diagnosis, she was referred to oncology for treatment. PAS, a rare condition often misdiagnosed, mimicked thromboembolism and autoimmune disease, underscoring diagnostic challenges.
