Correlation between histological subtype and type of bcl-2/IgH rearrangement in follicular lymphomas

The aims of this study were: 1) to identify the type of bcl-2 rearrangement in a Brazilian group of FL patients and 2) to correlate it to clinical features, International Prognostic Index (IPI), histological subtype, response to treatment and clinical outcome. We reviewed the diagnosis of 48 patients with FL and investigated the type of bcl-2 gene rearrangement using DNA from paraffin-embedded tumor samples obtained at the time of diagnosis. In 30 cases, we also obtained consecutive peripheral blood samples to search for the presence of bcl-2/IgH rearrangement. Molecular analysis identified 41 (86%) patients with MBR and 5 (10%) patients with mcr rearrangement. In this study, the type of rearrangement was not associated with clinical characteristics or IPI. In addition, the type of rearrangement did not have an impact on response to initial treatment or on clinical outcome. However, we found an association between the type of rearrangement and the histological subtype of FL, i.e., none of mcr -positive patients presented histological grade I (p=0.043). In this study, we could not demonstrate a relationship between the type of bcl-2 rearrangement and the response to treatment or outcome. However, we found a relationship between the type of rearrangement and FL histological subtype, information not previously reported.