Eastern Cooperative Oncology Group experience with the rappaport classification of non-Hodgkin's lymphomas.

Eastern Cooperative Oncology Group experience in the clinical application of the Rappaport Classification on Non-Hodgkin's lymphomas (NHL) is reviewed in 670 cases studied since 1972. The diagnoses of institutional pathologists were reviewed by the Pathology Panel and Repository Center for Lymphoma Clinical Studies. Diagnostic agreement in regard to histologic pattern (nodular versus diffuse) was excellent (90%) but was less favorable when concurrence as to both pattern and cell type was assessed (82% in NLDP and 60% or less in other subtypes). Disagreement in regard to NHL diagnosis is related to the complexity of present nomenclature and to the lack of support of pathology activities within cooperative groups. It is suggested that patients entered into group NHL studies be randomized into favorable and unfavorable groups, primarily on the basis of histological pattern.