CARCINOMA-LIKE SIGNET-RING CELLS IN GASTRIC MUCOSA-ASSOCIATED LYMPHOID-TISSUE (MALT) LYMPHOMA

We noticed the presence of epithelial signet-ring cells (SRCs) in a pr oportion of primary gastric B-cell lymphomas, and in some endoscopic b iopsies we found it difficult to decide whether they represented an as sociated carcinoma. To evaluate the frequency and nature of this pheno menon, we reviewed 108 stomachs resected for primary lymphoma, includi ng 70 mucosa-associated lymphoid tissue (MALT) and 38 non-MALT lymphom as. We found SRCs, either isolated or grouped in clusters, in 26 of 70 MALT lymphomas. The SRCs were always localized in the superficial por tion of the lamina propria and associated exclusively with lymphomatou s areas, Isolated and scarce SRCs were also found in four of 22 cases of polyclonal atypical lymphoid hyperplasia. Our data suggest that SRC s occurring in gastric MALT lymphomas represent a particular type of L EL in which the foveolar cells disaggregated by the lymphomatous infil tration acquire a globoid, signet-ring appearance, These ''foveolar'' LELs are found in 37% of MALT lymphomas and are usually associated wit h the more classic and constant ''neck'' LELs, which are localized bet ween the foveolae and mucopeptic glands. An awareness of the existence of the foveolar LEL may help avoid overdiagnosis of SRC carcinoma on gastric endoscopic biopsies.