Background:The EORTC clinical trial 20901, activated in1990, was designed to treat non-Hodgkin’s lymphomas (NHL) ofintermediate/high-grade malignancy according to the Working Formulation.Established in 1994, the R.E.A.L. Classification on NHL has now replacedall former classifications.
Patients and methods:We reanalysed all cases (n=273) documented by material available for review according to theR.E.A.L. Classification. In addition, we subdivided cases recognised asdiffuse large B-cell lymphoma (DLBCL) into three morphologicallydistinct categories, namely, large cleaved DLBCL (LC-DLBCL),T-cell-rich/histiocyte-rich B-cell lymphoma (T-cell-rich/histiocyte-richBCL) and CD30+ DLBCL with anaplastic cell features (CD30+ DLBCL).Finally, T/NULL anaplastic large-cell lymphoma (ALCL) cases weresubdivided into ALK+ and ALK− lymphomas. Review was performedindependently by two pathologists from two different centres.
Results:DLBCL (61%), T/NULL ALCL (15%) andmantle-cell lymphoma (MCL, 5%) were the main NHL categoriesrepresented in the study. Fifty-seven of one hundred sixty DLBCL caseswere further subclassified as LC-DLBCL (33 cases),T-cell-rich/histiocyte-rich BCL (13 cases) or CD30+ DLBCL (11 cases).The remaining cases were indicated as unspecified DLBCL. Aclinico-pathological correlation confirmed the findings of previousstudies suggesting that MCL, DLBCL and ALCL represent distinct entitieswith MCL being characterised by a short survival, in contrast with thelonger survival and less frequent progression typical of ALK+ comparedto ALK− ALCL. Within DLBCL, T-cell-rich/histiocyte-rich BCL showeddistinctive features at presentation whereas CD30+ DLBCL showed a trendtowards a more favourable prognosis, that might be comparable to that ofALK+ ALCL.
Conclusions:Our data further support the usefulness of theR.E.A.L. Classification and illustrate the feasibility of DLBCLsubtyping. Moreover, our results demonstrate the distinct clinicalcharacteristics of T-cell-rich/histiocyte-rich BCL and CD30+ DLBCL withanaplastic cell features suggesting that they may representclinico-pathologic entities.