BACKGROUND: Deregulated bcl-2 appears to prolong cell survival and to cooperative with c-myc in promoting cell proliferation. We investigated whether there is any clinicopathologic correlation between the survival and the frequency of bcl-2/JH rearrangement and bcl-2, c-myc protein expression in non-Hodgkin's lymphoma. METHODS: We conducted a study for bcl-2 mbr/JH rearrangement with polymerase chain reaction and for bcl-2, c-myc expression with immunohistochemical staining in 46 formalin-fixed, paraffin-embedded non-Hodgkin's lymphoma tissues of patients treated with CHOP chemotherapy including 37 specimens of diffuse large cell type. RESULTS: The bcl-2 mbr/JH rearrangement was positive in 13% (6/46) of non-Hodgkin's lymphoma specimens. For bcl-2, strong positive reaction (3+) and 2+ positive reaction were seen in 16 (35%) and 16 cases (35%), respectively; while 3+ and 2+ reactions were found in 20 (44%) and 16 cases (35%), respectively, for c-myc by immunohistochemistry. Eighty one percent of positive cases for bcl-2 were also positive for c-myc simultaneously. The 6 cases with bcl-2 mbr/JH rearrangement were weakly positive at 3 cases and strong positive at 3 cases for bcl-2 by staining. In cases of diffuse large cell lymphoma, high expression (3+) of bcl-2 & c-myc protein tended to have a shorter 2 year survival, though it was statistically not significant. CONCLUSION: High expression of bcl-2 and c-myc protein suggest that bcl-2 cooperate with c-myc in tumorigenesis of aggressive non-Hodgkin's lymphoma. The prognostic implication of bcl-2 and c-myc expression in diffuse large cell lymphoma patients needs to be evaluated in a larger, prospective cohort to draw a definitive conclusion.