Pulmonary artery pseudoaneurysm secondary to metastatic breast cancer

Computed Tomography Appearance of Unusual Nonaortic Thoracic Aneurysms and Pseudoaneurysms

Although aneurysms of the thoracic aorta are easily recognized on computed tomography (CT), nonaortic intrathoracic aneurysms and pseudoaneurysms are unusual and not often encountered by radiologists. These lesions can result in complications such as hemorrhage or symptoms from mass effect. In some cases, patients may be asymptomatic and the aneurysms may represent incidental findings. Radiologists should be familiar with the CT appearances of these rare vascular abnormalities to enable prompt diagnosis. The goals of this pictorial essay are to: (1) illustrate and describe the CT appearances of various unusual intrathoracic nonaortic aneurysms and pseudoaneurysms; (2) discuss the etiology and clinical significance of these lesions; and (3) discuss management options where appropriate.

Multiple Pulmonary Artery Pseudoaneurysms Secondary to Metastatic Uterine Leiomyosarcoma

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.