T-cell-rich B-cell lymphoma and lymphocyte-predominant Hodgkin's disease: two closely related entities?

T-cell-rich B-cell lymphoma (TCRBCL) is a recently described variant of non-Hodgkin's lymphoma. It may arise de novo or secondary to follicular lymphoma and large B-cell lymphoma. We present here seven cases of TCRBCL to emphasize a peculiar relationship to lymphocyte-predominant Hodgkin's disease. Morphologically, the neoplastic populations of all TCRBCLs, in addition to centroblast-like and immunoblast-like cells, comprised a few L+H-like elements. These neoplastic cells were all regularly scattered in a majority of reactive small T-lymphocytes as well as histiocytes. Moreover, tumour cells of TCRBCL, including the L+H-like elements of TCRBCL, expressed LCA and L26 but did not stain for Leu-M1 and BerH2, as is the case with the Reed-Sternberg cell L+H variant of lymphocyte-predominant Hodgkin's disease. Furthermore, the L26 immunoreaction in one of the cases, which otherwise presented as typical TCRBCL, disclosed a small subcapsular area resembling nodular paragranuloma because some few foci consisting of mature B lymphocytes with occasional L+H-like elements were seen. This also holds true for a second of the TCRBCLs presented that obviously coexisted with recurrent Hodgkin's paragranuloma 10 years after the primary manifestation. These findings indicate a close connection between TCRBCL and lymphocyte-rich Hodgkin's disease, and it may even be speculated as to whether TCRBCL represents merely a phenotypically different manifestation of this Hodgkin's subtype. Although the data presented here will not provide sufficient proof of this hypothesis, it seems clear that the nosology of TCRBCL in the context of current lymphoma classifications requires further elucidation.