SPECIFIC DETECTION OF HELICOBACTER-PYLORI AND NON-HELICOBACTER PYLORIFLORA IN SMALL-CELL AND LARGE-CELL PRIMARY GASTRIC B-CELL NON-HODGKINS-LYMPHOMA

Background: Primary gastric non-Hodgkin's lymphomas possibly develop i n response to local infection by Helicobacter pylori (H. pylori. We in vestigated the presence of H. pylori and non-H. pylori flora histologi cally in small- and large-cell primary gastric lymphoma using a specif ic staining method. Materials and methods. Specimens of 52 cases of pr imary gastric lymphoma (17 small cell, 35 large cell) were stained wit h modified Giemsa (MG) and immunohistochemically using a polyclonal an tibody against H. pylori (IHC). Results. Thirty-two cases (61.5%) (sma ll cell 76% versus large cell 53%, P > 0.05) showed immunoreactivity f or H. pylori in the mucosa surrounding the tumor. Remarkably, there wa s localization of H. pylori in the neck of the gastric glands in 3 cas es. Non-H; pylori flora was seen in 35 cases (76.3%) (small cell 53% v ersus large cell 74%, P > 0.05). In 20 cases, this non-H. pylori flora was mixed with H. pylori Five cases showed no bacterial flora at all. Conclusions: (1)Using immunohistochemistry, the prevalence of gastric lymphoma cases with H. pylori (61.5%) approximates that of H. pylori in the normal population. (2) No statistical difference was found betw een the occurrence of HI pylori and non-H. pylori bacterial flora in s mall- versus large-cell lymphoma. (3) Our results suggest that H. pylo ri may not be the only etiologic factor in primary gastric lymphoma.