T-CELL-RICH B-CELL LYMPHOMA - A CLINICOPATHOLOGICAL STUDY OF 8 CASES

Although T-cell-rich B-cell lymphoma (TCRBCL) is a recently recognized form of non-Hodgkin's lymphoma (NHL), limited information regarding i ts incidence, cellular origin, morphologic spectrum, and biologic beha vior is currently available, In this study, the clinicopathologic feat ures of eight patients with TCRBCL are presented, This neoplasm compri sed about 1% of all NHLs seen at Emery University Hospital over 2 year s, The male-to-female ratio was 1.6, and the mean age at diagnosis was 60 years, At presentation, TCRBCL was nodal in 88% of the patients an d widely disseminated in 50% of the patients, A complete remission was seen in three of the five patients treated with combination chemother apy that was directed at intermediate grade NHL. Three patients receiv ed inadequate or incomplete chemotherapy. One of these patients later achieved a complete remission with more intensive therapy, Two of the patients were not evaluable for response to therapy, The actuarial and disease-free survival rates of the group at 5 years were 72% and 21%, respectively. Morphologically, the lymph nodes in seven of eight case s were diffusely obliterated, whereas one had markedly expanded interf ollicular zones that lead to an initial diagnosis of T-zone lymphoma. All tumors were characterized by no more than 25% large lymphoid cells which were scattered in a background of small lymphocytes with round or irregular nuclei, The presence of numerous histiocytes imparted a l ymphoepithelioid appearance in two cases, Although immunoperoxidase st ains of frozen tissue were initially suggestive of a peripheral T-cell lymphoma in some cases, paraffin immunoperoxidase stains clearly esta blished the B-cell nature of the large cells, whereas most of the smal l cells were T lymphocytes, The clonal nature of the large cells was c onfirmed in seven cases by monotypic immunoglobulin (Ig) light chain r estriction or Ig gene rearrangements, Epstein-Parr virus genomic DNA w as detected in two of the six cases tested by polymerase chain reactio n or Southern blot analysis, but no evidence of a bcl-2 rearrangement was found in any of the five cases examined, These findings indicate t hat TCRBCL is an uncommon form of NHL with a therapeutic response and overall survival consistent with intermediate grade lymphoma, Paraffin immunoperoxidase stains and occasionally genotypic analysis are requi red to exclude the diagnosis of PTCL or diffuse lymphocyte predominant Hodgkin's disease, The authors found no morphologic or molecular evid ence to support a follicular center cell origin in these cases of TCRB CL.