Aortic intimal sarcoma: report of two cases with immunohistochemical analysis for pathogenesis.

Primary vascular neoplasms are rare entities. They were first described as arising spontaneously in the aorta and other vessels. However, in the past several decades, a number of systemic artery-derived vascular neoplasms, mostly sarcomas, have been reported as arising in intimate association with synthetic grafts. We describe two additional cases of intimal sarcoma seen at our institution. The first is an invasive intimal sarcoma detected in a thoracoabdominal aortic aneurysm at the time of surgical intervention. The second is a superficial spreading intimal sarcoma associated with a Dacron-coated graft, in place for 9 years, detected when the graft was replaced. When the patient died 3 months later, a metastatic subcutaneous sarcomatous lesion was detected at autopsy. In these cases, we studied selective molecular pathways that may be involved in the transformation of benign endothelium to malignant endothelium, with implications for possible therapeutic targets. These cases are presented in order to contribute additional data to the literature involving these vascular neoplasms and to potentially provide a spectrum of disease seen in the vasculature tissues that may arise spontaneously or after placement of a synthetic graft.