Rasmussen Aneurysm

Rasmussen aneurysm is an inflammatory pseudoaneurysmal dilatation of a pulmonary artery branch adjacent to or within a tuberculous cavity (1). This occurs during the healing of the disease and is caused by progressive weakening of the arterial wall, in which both the adventitia and the media are replaced by granulation tissue and then gradually replaced by fibrin, resulting in thinning of the arterial wall, segmental pseudoaneurysm formation, and subsequent rupture (2,3). These are commonly found in the upper lobes and distributed peripherally (3). Although rare, it commonly manifests as life-threatening massive hemoptysis, and CT angiography plays an important role in locating the lesion and guiding therapy (1) (Figure).

Images in a 63-year-old male patient in the emergency department due to massive hemoptysis and a history of treated tuberculosis. CT angiographic images (A, non–contrast material–enhanced axial; B, minimum intensity projection; C, contrast-enhanced axial in soft-tissue reconstruction; D, contrast-enhanced axial in lung reconstruction; E and F, three-dimensional reconstructions) show an opacity with spontaneously hyperdense content (* in A, nonenhanced image) in the left upper lobe superior lingular segment, compatible with hematoma, associated with multiple locules of air, as seen in B. The administration of the contrast medium revealed a 2.1-cm well-circumscribed aneurysm (white arrow in C, E, and F). D, Multiple small ground-glass centrilobular nodules (white arrowheads) are seen around the hematoma (*), likely related to endobronchial blood dissemination. G and H, Images from pulmonary arteriography reveal the aneurysm (black arrow) originating from branches of the left upper lobe superior lingular artery with active bleeding (black arrowheads). Selective catheterization was performed, followed by coil embolization. * indicates the hematoma in all images.