A case of mucosa-associated lymphoid tissue lymphoma of the gastrointestinal tract showing extensive plasma cell differentiation with prominent Russell bodies

Figure 1 Color-faded cobble-stone like erosion in the ileum (arrows).

Figure 2 Biopsy specimen taken from the erosion in the ileum, showing proliferation of mononuclear cells containing numerous Russell bodies in the submucosal layer. A: HE, × 100; B: × 400.

Figure 3 Immunohistochemistry. A: Immunohistochemistry for lambda light chains using biopsy specimen from the ileum (× 400); B: Atypical lymphocytes in peripheral blood diagnosed as T-prolymphocytic leukemia (Giemsa stain, × 1000); C: Immunohistochemistry for CD79a using biopsy specimen from the ileum (× 200); D: Immunohistochemistry for CD138 using biopsy specimen from the ileum (× 200).