Gastrointestinal: Gastric mucosa‐associated lymphoid tissue (MALT) lymphoma observed by magnifying endoscopy with narrow band imaging

Abstract

Mucosa-associated lymphoid tissue (MALT) lymphoma derived from the B-lymphocytes, rarely occurs in the gastrointestinal (GI) tract. The commonest site of occurrence is the stomach. Narrow band imaging (NBI) with magnifying endoscopy can identify MALT lymphoma and there have been several reports and case series on this. We presently report a 79-year-old man who underwent GI endoscopy as part of a health checkup. Conventional endoscopy showed a depressed reddish lesion in the posterior wall of the mid-gastric body (Figure 1A). Chromoendoscopy with indigo carmine identified this to be a depressed lesion. (Figure 1B) Magnifying endoscopy with NBI showed a cleare demarcation line of this depressed lesion (Figure 1C, arrows), and revealed an loss of the normal epithelium and abnormal micro-vessels that did not have the typical tree-branching calibre changes around white round lesions (Figure 1D). Endoscopic biopsy specimens taken from the lesion showed a diffuse proliferation of abnormal lymphoid cells within the mucosa (low-power histology—not shown). High-power histology showed a diffuse proliferation of small centrocyte-like cells and lymphoepithelial lesions. Immunohistochemical analysis was positive for CD20 but negative for CD3. He was diagnosed as having gastric MALT lymphoma. The positron-emission tomography/computed tomography showed only gastric uptake and no other extra-nodal disease. Based on the histopathological findings, a diagnosis of gastric MALT lymphoma (high-grade) was made, and combination-chemotherapy with pirarubicin hydrochloride, cyclophosphamide, vincristine sulfate and rituximab was started.