Figure 6: Histochemical staining. A) Cytokeratin was the stain for the epithelial components and here the normal ducts stain positive, while the lesion itself is negative. B) Leukocyte common antigen or CD45 is diffuse and strongly staining, thereby confirming that the lesion is of lymphoid origin. C) CD 3 is a T cell marker and the T cells are usually paracortical in a lymph node. Here, the lymphocytes surrounding the germinal centers light up. D) CD 20 is a B cell marker and they are usually located within the lymphoid follicles. Here the B cells light up with a strong membranous stain.