Most of extranodal lymphomas are localized in gastrointestinal tract, gastric lymphoma representing more than 50% of them. The role that Helicobacter pylori (H. pylori) plays in pathogenesis of gastric lymphoma has changed the therapeutic approach.

OBJECTIVE

Description of morphological features and immunohistochemical pattern of gastric lymphomas from patients admitted in University Hospital "Sf. Spiridon" Iaşi.

METHODS

Thirty four gastric lymphomas were investigated using routine histopathological technics and immunohistochemical staining based on a large panel of antibodies: CD3, CD5, CD20, CD79á, CD23, CD30, cyclin-D1, BCL2, BCL6, ALK1, Ki67, CK-cocktail, anti-H. pylori.

RESULTS

All gastric lymphomas were localized in the antrum, most of them being solitary and large-sized tumors. Ninety-seven percent were B-cell lymphomas, 41.17% were mucosa-associated lymphatic tissue lymphomas (MALT lymphomas), and the remaining were high grade lymphomas. Only one case was classified as peripheral T-cell lymphoma. Cytokeratin cocktail immunostaining improved the detection of typical lymphoepithelial lesions, which characterized exclusively the MALT lymphomas. The sensibility for H. pylori detection in gastric lymphoma cases was increased by 22% using anti-H. pylori antibodies.

CONCLUSIONS

Immunohistochemistry is a diagnostic method for gastric lymphomas, being useful in identification of lymphoepithelial lesions, detection of H. pylori infection, and is mandatory for lymphomas classification according to WHO criteria.