Detection of trisomy 3 in primary gastric B-cell lymphoma by using chromosome in situ hybridization on paraffin sections.

Recent studies in Western populations have shown that trisomy 3 is the most frequent chromosomal abnormality in primary gastric lymphoma (PGL). To study the incidence of trisomy 3 and its implications for the pathogenesis of PGL in Hong Kong, we have applied the technique of chromosome in situ hybridization in 13 cases of PGL by using archival paraffin-embedded tissue sections. Five cases of chronic gastritis were used as controls. Trisomy 3 was found in 9 (69%) of 13 cases, including cases of low-grade lymphoma and high-grade lymphoma with or without a low-grade component. Our findings are similar to the incidence of trisomy 3 reported in the Western literature. The persistent finding of trisomy 3 in various histologic grades of PGL suggests that it may be useful as a clonal marker in this group of neoplasms. Various molecular events involving chromosome 3 may be related to the pathogenesis of this group of lymphomas.