CD44 expression during tumor progression of follicular lymphoma.

Follicular lymphoma often progresses to diffuse type lymphoma. To elucidate the mechanisms of the diffuse evolution of follicular lymphoma, we investigated the expression pattern of CD44 in 28 cases of follicular lymphomas (FLs) using an immunohistochemical method and semi-quantitative PCR-Southern blot analysis. The FLs were divided into four groups: i) intrafollicular (IF); ii) infiltrative (INF); iii) partially follicular (PF); and iv) minimally follicular (MF), according to the histological classification by Lukes and Collins.