Breast
sarcomas arise from connective tissues of the breast and account for fewer than 1% of all breast
malignancies. They can be subclassified as primary breast
sarcomas, which arise de novo and are histologically diverse, and secondary breast
sarcomas, which arise as a result of radiation or
lymphedema and are most commonly
angiosarcomas. Two other
connective tissue neoplasms that occur within the breast include
phyllodes tumors and
desmoid tumors, which exhibit a spectrum of behaviors. Malignant
phyllodes tumors are biologically similar to primary breast
sarcomas, whereas
desmoid tumors are technically benign but often locally aggressive. Patients with breast
sarcomas often present with a rapidly growing mass or, in cases of radiation-associated
angiosarcoma, violaceous cutaneous lesions. Core needle biopsy is generally required to confirm the diagnosis of
sarcomas. Staging workup includes MRI and chest imaging, although these are not required in the case of benign phyllodes or
desmoid tumors. In general, localized breast
sarcomas should be resected, with the extent of resection tailored to histologic subtype. Radiation and
chemotherapy can be used in the neoadjuvant or adjuvant setting, but data are limited, so treatment decisions should be made on an individualized basis. Systemic
therapy options for metastatic disease and refractory breast
desmoids mimic those used for the same histologies when present in other sites. Given the rarity and heterogeneity of breast
sarcoma, as well as limited literature describing these entities, expert multidisciplinary evaluation is crucial for optimal decision making.