Epithelioid angiosarcoma of the breast involving the skin: a highly aggressive neoplasm readily mistaken for mammary carcinoma.

Background: Angiosarcomas are malignant neoplasms of endothelial cells. Angiosarcoma of the breast is a rare neoplasm that behaves in a highly malignant fashion. It must be differentiated from benign vascular proliferations and from mammary carcinoma.
Methods: We report on a 49-year-old-woman who presented with a large mass involving the left breast.
Results: The lesion had an erythematoviolaceous hue and livedoid pattern at the periphery. Histopathologic study showed an epithelioid malignant neoplasm, and immunohistochemical studies demonstrated that neoplastic cells expressed immunoreactivity for endothelial cell markers.
Conclusions: A diagnosis of epithelioid angiosarcoma of the breast was established. The patient was treated with radical mastectomy, but she refused any other additional therapy.