Colonic mucosa-associated lymphoid tissue lymphoma identified by chromoendoscopy

Figure 1 Colonoscopic findings. A, B: Before/after narrow-band imaging mode of the lesion; C: Diffuse granularity of the mucosa with loss of vascularity (arrows) was seen in the proximal transverse colon; D-F: Indigo carmine-dye spraying at the suspected pathologic lesion; G, H: After the indigo carmine-dye contrast method was applied, the lesion was distinguished more prominently from the surrounding normal colonic mucosa.

Figure 2 Histopathologic findings. A-C: Hematoxylin-eosin staining of the biopsy specimen showing dense proliferation of atypical lymphoid cells and infiltrated centrocyte-like cells in the mucosal layer (magnification: A, 40 ×; B, 100 ×; C, 200 ×); D: CD20-positive; E: Bcl-2-positive; F: CD10-negative; G: CD23-negative; H: Bcl-6-negative immunoreactivity of the biopsy specimen (100 × magnification).

Figure 3 Surgical finding of the resected specimen. An ill-defined, irregularly elevated mucosal lesion measuring 25 mm × 25 mm in diameter was observed (circle curve).