Breast sarcoma (BS) is a very rare and poorly studied condition. This has led to a lack of studies with a high level of evidence and to low efficacy of current clinical management protocols. Here we present our experience in treating this disease in the form of a retrospective case series study including discussion of clinical, imaging, and pathological features and treatment. We also compare the main clinical and biological features of six cases of BS (phyllodes tumors were excluded) with a cohort of 184 patients with unilateral breast carcinoma (BC) from a previous study performed at our institution. Patients with BS were diagnosed at a younger age, presented no evidence of lymph node invasion or distant metastases, had no multiple or bilateral lesions, and underwent a shorter length of hospital stay versus the breast carcinoma group. Where recommended, adjuvant chemotherapy consisted of an anthracycline-containing regimen, and adjuvant external radiotherapy was delivered in doses of 50 Gy. The comparison data obtained from our BS cases and the ones with BC revealed differences in diagnosis and treatment. A correct pathological diagnosis of breast sarcoma is essential for the right therapeutic approach. We still have more to learn about this entity, but our case series could add value to existing knowledge in a meta-analysis study.