Abstract
Pulmonary artery pseudoaneurysm (PAP) is a rare and potentially life-threatening vascular abnormality that is commonly associated with infections, such as tuberculosis. However, their occurrence in the setting of lung adenocarcinoma is exceedingly rare. We report a case of a 67-year-old man with stage III non-small cell lung cancer (NSCLC) who had a pulmonary artery pseudoaneurysm incidentally detected on follow-up maintenance imaging. The pseudoaneurysm was contiguous with pulmonary artery branches in the right lower lobe and associated with a progressively enlarging necrotic tumor region, suggesting that vascular invasion contributed to its formation. The patient was not experiencing any complications or hemoptysis at the time of identification; however, the pseudoaneurysm was deemed at risk for rupture and was successfully treated with coil embolization. This case highlights the importance of closely monitoring for vascular abnormalities in malignancy and early intervention to prevent potentially fatal complications.