Primary Breast Angiosarcoma
This focus shows low-grade angiosarcoma infiltrating breast adipose tissue. The lesion is subtle and may be missed. It consists of delicate, irregularly-shaped, variably dilated, anastomosing vascular channels lined by flattened endothelium lacking atypia. Such areas may be misdiagnosed as hemangioma or angiolipoma in core biopsies. Low-grade angiosarcomas of the breast are difficult to diagnose on limited material of needle biopsies. One should consider excising all low-grade vascular lesions of breast (except the most obvious perilobular hemangiomas) to avoid underdiagnosis of angiosarcomas.