The case reports a 49-year-old patient, drug-addicted, undernourished, and homeless, who was referred to our service presenting a diagnostic of breast sarcoma and ulcerating tumor which extended from the right breast to the right flank. She underwent hygienic mastectomy and, as it developed, she presented a range of complications, culminating in the recurrence of the tumor and pulmonary metastasis few months after her initial treatment. There is relevance in our study not only because it reports the development of the breast sarcoma, rare neoplasm, and its aggressiveness with fast recurrence, but also because it exposes the impact of biopsychosocial behavior of this patient in her clinical outcome.