Fig. 2

Histopathologic findings of surgical biopsy specimen. a Atypical lymphoid cells with irregular nuclear membranes diffusely infiltrate the breast tissue. Cell discohesiveness is apparent, and tumor cells are in a linear pattern, resembling infiltrating lobular breast carcinoma. b Periductal infiltration was also observed (upper: hematoxylin and eosin staining). AE1/3 staining (lower), epithelial marker, was confirmed on normal breast ducts. c Immunohistochemical findings of CD20, CD10, TdT, and PAX5 (from the left to the right)