Lymphoepithelial carcinoma of the breast (LELC) is a rarely encountered form of breast carcinoma, and there is limited information treatment for this entity. We present a case of a 55-year-old postmenopausal female presenting with a left breast mass on screening mammogram with core needle biopsy showing lymphoepithelial carcinoma. The patient was treated with surgical resection of the mass and sentinel lymph node biopsy, followed by adjuvant chemotherapy and radiation. Given the rarity of this type of breast carcinoma, our case study continues to add to the treatment considerations in the literature, specifically the role of sentinel lymph node.