Sarcoma of the mammary glands is extremely rare. Liposarcoma, leiomyosarcoma, rhabdomyosarcoma, as well as hemangiopericytoma, are part of the soft tissue sarcoma group. Little is known about the progress, prognosis and dissemination of this infrequent tumor entity. We present the case of a woman, who received primary diagnosis of a malignant hemangiopericytoma of the left breast. She underwent a mastectomy with an axillary lymph node sampling (stage pT3 pN0 cM0), as adjuvant therapy was not mandatory. Eight months after diagnosis, the patient presented with lumbar back pain, gluteal pain and right accentuated adynamia in both legs because of a disseminated osseous metastasis. Diagnostic investigation presented a cerebral, pulmonary, cutaneous, hepatic and pleural metastatic disease. Two months after initiation of chemotherapy the patient died. Diagnostic criteria and treatment principles in the metastatic situation are presented in addition to the literature to give a review about this rare malignancy.