Figure 3.

Case 3. A: Nodular areas, sometimes resembling germinal centers with mantle zones, are surrounded by a diffuse lymphoid infiltrate. H&E; original magnification, ×40. B: At high magnification, the diffuse infiltrate is mainly composed of small lymphocytes with round nuclei, whereas the nodular areas show more nuclear irregularity with medium-sized cells with partly cleaved nuclei. H&E; original maginfication, ×400. C: The nodular areas strongly express IgD, and (D) lack p27, which is positive in the diffuse component. Immunoperoxidase; original magnification, ×100. E-F: Cyclin D1 is positive in the nodular areas. Note that some of the nodules are surrounded by a normal mantle zone area which are negative for cyclin D1, as well as the diffuse component. Immunoperoxidase; original magnifications, ×200 (E) and ×400 (F).