[Four cases of malignant primary breast lymphoma].

Primary malignant lymphoma of the breast (PBL) is comparatively rare in Japan.Herein, the authors present report 4 cases of PBL. All patients had the primary finding of a palpable left breast mass.Malignant lymphoma was strongly suspected by core needle biopsy, and final diagnosis was made on surgical specimens. All cases were diffuse large B-cell lymphoma and were treated with targeted chemotherapy with R-CHOP. Only 1 of the 4 patients needed multidisciplinary therapy due to advanced age.Whenever PBL is suspected, targeted therapy should be considered.