Primary low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma with polypoid appearance. Polypoid gastric MALT lymphoma: A clinicopathologic study of eight cases

In the current study, we report eight cases with primary low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma endoscopically characteri zed by polypoid lesions in order to highlight their clinicopathologic signi ficance. Four patients were male, their ages ranging from 40 to 78 years ol d. The resected specimens revealed a histology of low-grade MALT lymphoma c haracterized by dense lymphocytic infiltration predominantly in the submuco sa and a relatively monotonous proliferation of centrocyte-like cells with reactive follicles and infrequent lymphoepithelial lesions. The tumor cells were of CD5(-), CD10(-), CD20(+), BCL2(+) and cycline D1(-) phenotype, and showed a monoclonal rearrangement of immunoglobulin heavy chain genes in t he five of six cases examined. Interestingly, Helicobacter pylori (H. pylor i) was detected in three (37.5%) of the eight patients, which was significa ntly tower than previous reports. Two of the H. pylori-positive cases initi ally underwent H. pylori eradication, but showed no change In their lymphom as after the cure of H. pylori infection. The clinicopathologic findings of the present cases appeared to closely resemble those of colorectal MALT ly mphoma with a polypoid appearance and few association of H. pylori Infectio n in their pathogenesis. These gastric polypoid cases may merit separate; c onsideration because of the therapeutic problems they pose.