Tumor progression in malignant lymphomas

Low grade lymphomas which derive from either the B or T lineage commonly progress to a more aggressive form of lymphoma. Among follicular lymphomas this progression usually manifests pathologically by a change to a diffuse pattern of infiltration as well as by a change to a proliferation dominated by large lymphoid cells. A similar progression to a proliferation of large lymphoid cells may be seen in small lymphocytic lymphomas and in mycosis fungoides or other T cell lymphomas. To investigate whether certain tumor cell or host cell features may be associated with tumor progression, we and other investigators have applied various cell markers to lymphoma subtypes. Clinical correlations with tumor cell features such as lineage derivation, histocompatibility antigen expression, lymphocyte function-associated antigen (LFA-1) expression, and proliferation-associated marker expression are described. The clinical significance of large numbers of CD4+ cells in small cell B lineage lymphomas is also presented.