Abstract

INTRODUCTION

Diffuse large B cell lymphoma (DLBCL) and Burkitt lymphoma (BL) are mature agressive B cell lymphomas that have heterogeneous clinical, morphological, immunofenotypical and cytogenetic features, and have widely different clinical course. In this study, the immunohistochemical and cytogenetic features seen in DLBCL and BL and the association between the prognosis are studied. Also the characteristics that can be used to differentiate DLBCL and BL is defined.

METHODS

Totally 56 cases (45 DLBCL and 11 BL), which were diagnosed in Gazi University, Medical School, Department of Pathology between 2000 and 2007 were included to study. Bcl-2, bcl-6, CD10, MUM-1 and Ki-67 antibodies were performed immunohistochemically and c-myc amplification, PTEN deletion and t(14;18) translocation was evaluated by fluorescent in situ hybridization.

RESULTS

The expression of bcl-2, bcl-6 and CD 10 were 55.6%, 35.6% and 25.8% respectively in DLBCL cases. In the cases of BL, all the cases were bcl-2 negative, bcl-6 and CD 10 positive. While the proliferation index of Ki-67 were 63.2% in DLBCL, it was 97.2% in BL (p=0.001). The ratio of c-myc amplification was 80% in BL and 43.7% in DLBCL (p<0.05). The ratio of t(14;18) translocation and PTEN deletion was 7.7% and 26.7% in DLBCL, while it was 20% and 9.1% in BL (p>0.05).

DISCUSSION AND CONCLUSION

The usage of immunohistochemical panel, including CD 10, bcl-6, bcl-2 and Ki-67 to differentiate between DLBCL and BL is absolutely beneficial. Also Ki-67 proliferation index higher than 95% is helpful for the diagnosis of BL. Altough c-myc amplification is highly detected in BL cases, it can be seen in DLBCL slightly. No statistically significant association was detected in t(14;18) and PTEN deletion between the distinction of DLBCL and BL.