Gastric mucosa associated lymphoid tissue [MALT] lymphoma, histopathological and immunohistochemical study in endoscopic biopsies in King Abdulaziz University hospital, Saudi Arabia

ABSTRACT

The histological criteria useful for the diagnosis of MALT lymphoma are well established. On the other hand, the histological changes of the gastric mucosa adjacent to MALT lymphoma have not been adequately described, in spite of the high frequency of intestinal metaplasia, atrophy and occasional dysplasia. This study was performed on 104 biopsies which included the endoscopic biopsies of 27 cases of MALT lymphoma, 27 cases of gastric carcinoma and 54 cases of H pylori associated gastritis. Cellular lymphoid atypia, diffuse lymphoid growth pattern, lymphoepithelial lesions and immunoreactivity of the diffuse lymphoid infiltrate with at least one of the B cell markers are important features for MALT lymphoma. The association of H pylori, lymphoepithelial lesions and the surface erosion was most likely seen in association of MALT lymphoma. The association of gastric dysplasia, gastric atrophy and intestinal metaplasia was most likely seen in gastric carcinoma while the association of lymphoid follicles, intestinal metaplasia and H pylori was most likely in association with non neoplastic process but not exclusive. Reactive germinal centres may be observed in H pylori associated gastritis but they must. not be exclusive for MALT lymphoma. Identification of H pylori does not exclude a concomitant MALT lymphoma. Also diffuse lymphoid infiltrate that showed immunoreactivity of T and B markers is supportive of a reactive or an inflammatory process