Primary breast diffuse large B-cell lymphoma: a clinicopathological analysis of four cases

Objective To discuss the clinical pathological features, diagnosis and differential diagnosis, therapy and prognosis of primary breast diffuse large B-cell lymphoma (PB-DLBCL) . Methods The clinical manifestations, pathological features, immunophenotypic characteristics of 4 cases of PB-DLBCL were retrospectively reviewed, and related literatures were reviewed. Results All of the 4 patients were women, aged 45 to 69 years, with the median 58.5 years. There were 3 cases of lesions involving the left breast and 1 case of the right breast. Microscopic observation showed that the normal structure of the mammary gland was destroyed, and no capsule was seen. There was a large number of large-to medium-sized heterotypic lymphoid cells which characterized as diffuse infiltration between the remaining ducts or lobules of mammary gland. Tumor cells infiltrated adipose tissue, mainly as central blast-like cells (3 cases) and immunoblast-like cells (1 case) . No lymphatic epithelial lesions were observed. The immunophenotype showed 4 cases were non-GCB type. Immunostaining showed that the neoplastic cells were LCA, CD20, CD79a and MUM-1 positive. Ki67 index were from 50% to 80%. The follow-up time of these cases was until Dec. 2017. There was one recurrence during the follow-up period. The patient died 13 months later. One patient was alive and had survived for 66 months. Two patients were lost to follow-up. Conclusions PB-DLBCL is extremely rare, mainly found in women. Most of the cell origin types are non-GCB type, which is often misdiagnosed as breast cancer. The diagnosis of PB-DLBCL is confirmed by pathological biopsy and immunohistochemical markers. The treatment is not clear, and a comprehensive treatment plan such as R-CHOP/CHOP chemotherapy combined with radiotherapy is recommended. Key words: Breast; Diffuse large B-cell lymphoma; Immunohistochemical; Clinicopathology