Abstract
We herein report a unique case of aortic rupture due to co-localization of aortic intimal myofibroblastic sarcoma (IMFS) and urothelial carcinoma (UC). A 76-year-old man who was being followed up after surgery for UC 5 years earlier developed aortic rupture and underwent emergency surgery. Intraoperatively, a tumorous mass on the luminal side of the aortic arch was found near the rupture. A histopathological analysis of the mass revealed aortic IMFS. Furthermore, co-localization of IMFS and UC cells was found near the rupture. The fragility of the aortic wall due to co-localization of IMFS and UC was believed to contribute to the aortic rupture.