EXPRESSION OF ADHESION MOLECULES IN PRIMARY B-CELL GASTRIC LYMPHOMA AND LYMPHOID FOLLICLES

To determine whether primary B-cell gastric lymphoma (GL) is one entit y, we examined the expression of three adhesion molecules in the micro vasculature of lymphomas. Stromal cells, including vascular endothelia l cells, within lymphoid follicles of the gastric mucosa were also inv estigated. Twenty-two surgical specimens of GL were classified into lo w-grade malignant lymphoma arising from mucosa-associated lymphoid tis sue (low-grade lymphoma, n=9), and high-grade malignant lymphoma with (secondary high-grade lymphoma, n=6) or without (primary high-grade ly mphoma, n=7) a low-grade component. The proportion of venules positive for ELAM-1 or VCAM-1 was significantly higher (P<0.001) in primary hi gh-grade lympho ma than in low-grade and secondary high-grade lymphoma s. In gastric lymphoid follicles, the stromal cells of the germinal ce ntre (GC) were positive for ICAM-1, ELAM-1, and VCAM-1, but the stroma l cells of the marginal zone (MZ) were positive only for ICAM-1. We fo und two patterns of adhesion molecule expression in gastric lymphoid f ollicles, the MZ pattern and the GC pattern. Low-grade and secondary h igh-grade lymphomas, which had the MZ pattern, might be of MZ-cell lin eage, but most primary high-grade lymphomas, which had the GC pattern, might be of follicular centre cell lineage.