BCL-6 GENE HYPERMUTATIONS IN DIFFUSE LARGE B-CELL LYMPHOMA OF PRIMARYGASTRIC ORIGIN

The presence of the bcl-6 gene hypermutation was studied in 40 Hong Ko ng Chinese patients with diffuse large B-cell lymphoma. The primary si tes of involvement were nodal in 18 cases and gastric in 22. Hypermuta tions at the E1.11 segment of bcl-6 gene were detectable in 16/22 (73% ) primary gastric and 4/18 (22%) primary nodal lymphoma (P<0.01). Thre e of the 22 cases of primary gastric but none of the nodal lymphoma ha d mutations at E1.12. The proportion of hypermutated cases in the grou p with bcl-6 gene rearrangement was similar to that of the germ-line g roup (70% v 75%). High frequency of bcl-6 gene hypermutations was foun d in diffuse large B-cell lymphoma of the stomach and they were indepe ndent of rearrangement of the gene as detected by Southern analysis, U nlike gene rearrangement, hypermutations of the bcl-6 gene did not app ear to carry any prognostic significance clinically.