Breast Angiosarcoma: Imaging Features With Histopathologic Correlation

Breast angiosarcoma is a rare malignancy of endothelial origin that can be categorized as primary angiosarcoma (PAS) or secondary angiosarcoma (SAS) based on etiology. Primary angiosarcoma typically affects younger women with no known risk factors, whereas SAS of the breast typically develops in older women who have undergone breast cancer treatment. There are two types of SAS, one that develops in the setting of chronic lymphedema and one that develops as a radiation-associated neoplasm after breast-conserving therapy (BCT). Clinically, PAS often presents as a palpable mass that may be rapidly growing, whereas SAS presents with skin changes such as erythematous plaques or nodules or with areas of skin discoloration. Mammographically, the appearance of PAS can be nonspecific and may be obscured by the dense tissue that is characteristic of the young patient population it typically affects. Cases of mammographically occult PAS have been visible at US and MRI. Mammography and US have been found to be less sensitive than MRI for the diagnosis of secondary radiation-associated angiosarcoma. Angiosarcomas, both PAS and SAS, are graded, depending on degree of differentiation, as low, intermediate, or high grade. Endothelial markers such as ERG and CD31 immunohistochemical stains are used to support the diagnosis of angiosarcomas. In this article, we review the clinical presentation, imaging findings, associated histopathology, and treatment of primary and secondary breast angiosarcoma.