RESUMO
INTRODUCTION: Breast sarcomas are rare with an annual incidence of 4.6 cases/1,000,000 women. They can appear as primary forms or secondary to radiation therapy or chronic lymphedema. PRESENTATION OF CASE: A 41 year old woman attended our hospital after having noticed an increase in the size of her fibroadenoma. The examination revealed a 7cm retroareolar nodule. Breast sonography described a hypoechoic bilobulated lesion and MRI showed a large size polinodular image, suggesting a Phyllodes tumor. A core needle biopsy was performed with a histological result of low-grade fusiform cells sarcoma on Phyllodes tumor so we proceeded to surgical treatment with a mastectomy. After two years and a half she noticed a tough nodule over the mastectomy scar, which was resected with a histological result of fusiform cells sarcoma. Considering the diagnosis of recurrence of the disease, surgery was undertaken. DISCUSSION: Breast sarcoma is a rare but aggressive entity. Core biopsy is the procedure of choice for the diagnosis. Lymphatic spread is uncommon so nodal status in breast sarcoma is less informative. Staging study differs from other breast tumors and chest computed tomography is helpful since lungs are the predominant metastatic sites. The use of radiotherapy or chemotherapy is controversial and will depend on the risk of tumor recurrence. CONCLUSION: Surgery represents the only potentially curative therapy for breast sarcoma. Tumor size and adequate resection margin are the most important prognostic factors. Approximately 80% of recurrences appear in the first two years.