Teaching point: The probable mechanism of pseudoaneurysm formation related to metastatic neoplasm is a tumor embolus penetrating and destroying the vessel wall. Pulmonary artery pseudoaneurysm (PAP) related to metastatic neoplasm is rare. We describe a unique case of multiple PAPs secondary to metastatic uterine leiomyosarcoma and demonstrate the serial chest computed tomography to support the theory that the tumor begins as a tumor embolus, followed by infiltration and breakdown of the vessel wall, leading to aneurysmal dilatation and invading the perivascular tissue.