FIGURE 4

BCL 10 immunostaining of MALT lymphoma and diffuse large B-cell lymphoma of the colon and rectum. A and B, BCL 10 immunostaining in API2-MALT1–positive diffuse large B-cell lymphoma with MALT lymphoma component (Case 8). A, nuclear and cytoplasmic expression of BCL10 in large lymphoma cells. Note BCL10–negative nuclei of intermingling cells (arrowheads). B, nuclear and cytoplasmic expression of BCL10 in MALT lymphoma component. C, BCL 10 immunostaining in API2-MALT1–negative MALT lymphoma. Only cytoplasmic reactivity is seen without nuclear-expression pattern.