Pathologic features of the gastric mucosa adjacent to primary MALT-lymphomas

The frequency of reported cases of primary gastric mucosa-associated lympho id tissue (MALT)-lymphoma is increasing worldwide. Helicobacter pylori play s a preponderant role in its pathogenesis. Gastric MALT-lymphoma arises fro m nonrecirculating centrocytelike cells located at the periphery of reactiv e lymphoid follicles, which are common in patients infected with this micro organism. Histopathologic features other than lymphoid follicles have not b een well described. In this study the authors describe the morphologic chan ges in the gastric mucosa adjacent to MALT-lymphomas. From the files of the departments of pathology at the Institute Nacional de Cancerologia and the Institute Nacional de Ia Nutricion in Mexico City, primary gastric MALT-ly mphomas were retrieved. Patients with hematoxylin-eosin-stained histologic sections, including the overt neoplasia and the neighboring gastric mucosa, were selected. Lymphoid follicles as well as intestinal metaplasia, atroph y, and eosinophils were evaluated as present or absent and graded as propos ed by the Updated Sydney System for gastritis. Fifty-one patients were elig ible for analysis. There were 35 low-grade and 16 high-grade primary MALT-l ymphomas. Forty-seven patients (92.6%) showed reactive lymphoid follicles i n the neighboring mucosa, 32 patients (69.5%) had intestinal metaplasia, an d 26 patients (54.1%) demonstrated atrophy. In 41 patients (73.8%) there wa s an increased number of eosinophils. Our findings suggest that lymphoid fo llicles, intestinal metaplasia, atrophy, and eosinophils in an endoscopic b iopsy are markers of both gastric lymphoma and carcinoma.