Pulmonary artery sarcoma (PAS) is a rare and aggressive mesenchymal tumor with an overall poor prognosis1-5. Due to similar clinical and radiologic findings, PAS is often misdiagnosed as a pulmonary embolism (PE) frequently leading to prolonged anticoagulation therapy, which delays the correct diagnosis 1-3. By presenting this clinical case our objective is to emphasize characteristic CT findings that favour a neoplastic origin of a pulmonary intravascular filling defect. PET-CT and MRI have also an important potential role in its diagnosis and therapeutical management.