FIG. 2.

Pathological examination confirmed the diagnosis of pseudoaneurysm. Hematoxylin and eosin staining showed gross thickening of endothelial and smooth muscle layers in the proximal artery but disruption of vascular integrity more distally (A–C: proximal to distal). Elastic tissue (D) and CD31 (E) staining showed a disrupted epithelial layer and internal elastic lamina (arrowheads) and strong expression of smooth muscle actin (E) in the expanded vessel wall (proximal artery: A–F). Elastic tissue (G) and CD31 (H) staining showed more severe disruption of epithelial and elastic layers, and desmin staining (I) confirmed expansion of the smooth muscle layer (distal artery: G–I). Original magnification × 40 (A–I).