Intimal sarcoma of the abdominal aorta and common iliac arteries presenting as epithelioid angiosarcoma of the skin: a case report.

Intimal sarcoma (IS) is the most common type of sarcoma of the aorta. IS tumor emboli can involve various organs, including the skin. However, a limited number of IS cases with an initial presentation of skin metastasis has been reported. Cutaneous metastasis as a form of epithelioid angiosarcoma (EAS) has not been well described. Herein, we present a 61-year-old Japanese man with an initial presentation of EAS of the skin, followed by multiple metastases to the skin as a form of EAS prior to detection of IS of the infrarenal aorta and common iliac arteries. In our case, the IS was CD31 and cytokeratin positive but did not express CD34 and factor VIII-related antigen. The EASs in our case exhibited diffuse CD31 expression, and focal factor VIII-related antigen and cytokeratin expression were observed throughout the tumor, including the neoplastic vascular structure; CD34 expression was not identifiable. IS metastasis to the skin has been documented as a form of angiosarcoma. However, IS metastasis has not been well described as a form of EAS. Our case could prove a morphological change from IS to EAS. Given the rarity of primary cutaneous EAS, it is recommended that primary sites other than the skin should be thoroughly investigated when EAS of the skin is encountered.