Thromboembolism in Pulmonary Artery Sarcoma

Pulmonary artery sarcoma, although rare, must be considered in the differential diagnosis of pulmonary thromboembolism. Clinically and radiologically, it may imitate pulmonary embolism, making diagnosis difficult and delaying treatment. Patients often have no symptom resolution despite therapeutic anticoagulation. Visualization of filling defects within a pulmonary artery on contrast-enhanced CT cannot reliably differentiate between pulmonary thromboembolism and malignant lesions like leiomyosarcoma. FDG PET-CT offers the potential for identification of malignant lesions. The authors report a case with pulmonary artery thromboembolism due to thrombi formed on a pulmonary artery leiomyosarcoma. Integrated FDG PET-CT showed no FDG-uptake along the major part of the filling defect within the right main pulmonary artery suggesting blood clot and increased uptake along the posterior wall of the right main pulmonary artery and the left lower lobar artery suggesting malignancy.