Figure 4c. Low-grade gastric MALT lymphoma with a mass, an associated central ulcer, and another ulcer in an 80-year-old man. The probable diagnosis was advanced gastric carcinoma. (a) Compression spot radiograph shows a well-demarcated mass (solid arrows) with a central ulcer (u) and an adjacent filling defect (open arrow) with converging folds in the antrum. (Reprinted, with permission, from reference 18.) (b) Photograph of the resected specimen shows the mass (solid arrow) and the central ulcer (u) (the so-called bull’s-eye appearance) in the antrum. Another ulcer (open arrow) is accompanied by a small mass, which caused the filling defect seen in a. (c) Low-power photomicrograph (original magnification, x10; hematoxylin-eosin stain) shows extension of tumor cells (blue stain) to the muscle layer. m = mucosa, pm = proper muscle, sm = submucosa. (d) Higher-power photomicrograph (x40) of the area in the top left corner of c shows normal gastric mucosa on the left and replacement by lymphoma cells on the right.