Histopathologic features of marginal zone B-cell lymphoma or MALT lymphomas. These lymphomas are defined by the presence of lymphoepithelial lesions and proliferation of tumor cells composed primarily of small cells (A). One of the major immunophenotypic characteristics is the presence of extensive, dense, packed CD20⁺ B-cell lymphoid infiltrate (D). A few CD3⁺ T lymphoid cells are interspersed within the B cells (B). The lymphoid cells are also CD10^- (C). Images were captured with a Leitz DM-RB microscope equipped with a 40x/0.70 NA objective lens and a JVC 3-CCD camera (KY-F50; Claravision, Massy, France). Images were processed with Claravision software and Adobe Photoshop (Adobe Systems, San Jose, CA). Images in panel A were stained with hematein-eosin-safran staining; those in panel B, with anti-CD3 immunostaining (polyclonal antibody A0452; Dakocytomation, Glostrup, Denmark); those in panel C, with anti-CD10 immunostaining (monoclonal antibody 56C6, NCLCD10; Novocastra, Newcastle upon Tyne, United Kingdom); and those in panel D, with anti0CD20 immunostaining (monoclonal antibody L26, Dakocytomation).