Breast malignant lymphoma can be classified as primary (PBL) or secondary (SBL). The incidence of PBL is low, accounting for 0.04%–0.5% of breast tumors. Most cases of PBL originate from B cells, with diffuse large B-cell lymphoma (DLBCL) being the most common subtype. The median age of onset is 60–65 years. It typically manifests as a unilateral, painless breast mass with or without axillary lymphadenopathy. The mass is of moderate consistency, well-defined, and mobile, with minimal involvement of the nipple and skin. Treatment involves multiple modalities, including surgery, radiotherapy, and chemotherapy. Surgery is primarily performed to obtain a pathological diagnosis.