Abstract: Objective: To investigate the clinical features,diagnosis and treatments of primary breast diffuse large B-cell lymphoma(PB-DLBCL),and to provide the basis for its clinical treatmemt. Methods: Three patients with PB-DLBCL were examined by imaging,pathology and bone marrow cytology. The curative effect was observed,while the related literatures were also reviewed. Results: Three patients with PB-DLBCL were female and had the clinical manifestations (painless breast mass) and their imaging findings were similar to breast cancer. the 3 patients,one patient underwent excisional biopsy in the assessment of breast nodules,followed by chemotherapy with 4 cycles of R-CHOP +4 cycles of CHOP+ 1 prophylactic intrathecal injection treatment,no recurrence was found in 1 year's follow-up;the other 2 patients were diagnosed by core needle biopsy,receiving 2 cycles of CHOP and 1 cycle of CHOP, respectively,getting very good partial remission (VGPR) and complete remission (CR);they still received chemotherapy,and the process was smooth. Conclusion: Core needle biospy along with immunohistochemical method combined with clinical data is an effective technique for the diagnosis in the patients with when unilateral painless mass as the first symptom and highly suspected as PBL.The elementary role of chemotherapy of R-CHOP/CHOP is preferred for the patients.Central nervous system (CNS) prophylaxis may improve the prognosis in the early treatment.

Key words: chemotherapy program, myelocytology, breastneoplasms, diffuse large B-cell lymphoma