Angiosarcoma after breast conservation: diagnostic pitfalls.

Angiosarcomas are aggressive tumors of endovascular origin. Although angiosarcomas are relatively rare, they are being reported with increasing frequency in patients who have previously undergone breast conserving therapy. The initial clinical presentation of angiosarcomas after breast irradiation is often similar to the presentation of recurrent breast carcinomas. In addition, the histologic and cytologic appearance of posttreatment angiosarcomas can be highly suggestive of recurrent breast carcinoma. Immunohistochemical stains are often required to make an accurate distinction between the 2 entities. An accurate diagnosis is essential, because prognosis and treatment are different for each condition. An early and accurate diagnosis is aided by a high index of suspicion by clinician and pathologist. Herein, a case history is presented that underscores the pitfalls in attempting to achieve an accurate diagnosis.