Angiosarcoma is a rare disease of the breast with the reported incidence of only 0.04% of all breast malignancies. The etiology of angiosarcoma remains unknown. It occurs post-mastectomy, in association with chronic lymphedema (Stewart-Treves syndrome), or after radiotherapy. We present a patient with angiosarcoma which developed 12 years of the diagnosis of breast carcinoma and 8 years of the operative procedure and radiotherapy for disease recurrence. A small angiomatous lesion of a few mm in size, cytologically suspect of vascular tumor (hemangioma or hemangiopericytoma) and histopathologically verified to be an atypical vascular lesion, was detected two years before breast enlargement and cytologic and histologic diagnosis of angiosarcoma. The patient died 15 months of the diagnosis of angiosarcoma, after two tumor recurrences and intrathoracic cavity invasion.