Oligoclonal immunoglobulin heavy chain gene rearrangement in a childhood immunoblastic lymphoma. Presentation as a polyphenotypic atypical lymphoproliferative reaction.

The authors describe a diagnostically difficult case of childhood lymphoma that presented as an atypical polyphenotypic lymphoproliferative reaction. Initial immunophenotyping revealed the presence of IgG, IgA, kappa, and lambda within the neoplastic lymphocytes. The patient had circulating plasmacytoid lymphocytes and a polyclonal hypergammaglobulinemia. The patient died of widespread immunoblastic lymphoma in two months. Postmortem tumor DNA showed a oligoclonal pattern of immunoglobulin heavy chain gene rearrangement. Blots for T-cell receptor beta-chain rearrangement showed germline bands. Epstein-Barr virus DNA was present within tumor cells, but there was no history of prior immunosuppression or serologic evidence of Epstein-Barr virus infection. The apparent polyclonal nature of the immunoproliferation delayed the institution of chemotherapy.