Post-breast cancer treatment-related angiosarcomas were first observed in lymphedematous extremities after mastectomy and are now being reported with increasing frequency after lumpectomy and radiation. A case history is presented of a BRCA2 carrier who had a postmastectomy chest wall angiosarcoma but had neither therapeutic radiation nor clinically evident lymphedema. The absence of established risk factors led to speculation that the BRCA2 germline mutation could be a causative factor in the development of this patient's angiosarcoma. A literature review supported this concept.