Pulmonary artery filling defects - Not all are pulmonary emboli

Differentiating pulmonary artery sarcoma from pulmonary artery emboli is challenging since the clinical presentation and imaging features of both conditions are often similar. Timely differentiation of the two conditions is important as delayed diagnosis often results in the progression of pulmonary artery sarcoma leading to poor prognosis and unnecessary anticoagulant therapy. We describe a case of a middle-aged male, who was initially diagnosed with pulmonary embolism, but later diagnosed with a pulmonary artery sarcoma. The case report emphasizes the importance of early imaging findings, which may raise the suspicion prompting further assessment of alternative diagnoses such as pulmonary artery sarcoma.