Biopsies of the stomach, duodenum, and terminal ileum revealed infiltration of the intestinal mucosa by sheets of atypical monocytoid lymphocytes positive for CD20, multiple myeloma-1, and IgA and destruction of crypts with lymphoepithelial lesions (Figure 2); additional stain was positive for Helicobacter pylori. Here, CD79A is linked to plasma cell myeloma.