Stage‐related differences of mitotic and apoptotic indices, and bcl‐2 protein expression in diffusely growing non‐Hodgkin's lymphomas

The present study examined whether growth characteristics of diffusely growing non‐Hodgkin's lymphomas (NHL) may differ as a function of stage. Among 105 NHL of various types and sub‐types (REAL [Revised European‐American Lymphoma] classification), localized (Ann Arbor pathologic stages I + II) lymphomas exhibited clearly higher indices for mitotic activity, apoptosis and cell turnover, as well as a significantly lower percentage of cells containing immunohistochemically detectable bcl‐2 protein, than disseminated (stages III + IV) NHL. A similar pattern emerged when high‐grade (Kiel classification) lymphomas only were evaluated. Low‐grade NHL showed analogous, but less marked, stage‐dependent characteristics, with the exception of median percentages of bcl‐2+ cells, which remained comparable in all stages. Our findings are consistent with the notion that dissemination of diffusely growing NHL is usually associated with reduced cell turnover and, in high‐grade lymphomas, with the generation of longer‐lived cells. © 1996 Wiley‐Liss, Inc.