B-cell lymphoproliferative disorders after bone marrow transplant. An analysis of ten cases with emphasis on Epstein-Barr virus detection by in situ hybridization.

Ten patients with B-cell lymphoproliferative disorders (BLPD) after bone marrow transplant were studied in a retrospective analysis of 81 specimens available from biopsy and autopsy material. Histologic review, immunophenotyping, and in situ hybridization (ISH) for Epstein-Barr virus (EBV) sequences were done. Sixty-four specimens showed morphologic evidence of BLPD, demonstrating a heterogeneous spectrum with various degrees of plasmacytoid differentiation. Immunophenotypic evidence of clonality was found in six patients. The ISH detected EBV sequences in all ten patients, including 60 of the 64 specimens with morphologic evidence of BLPD. In addition, ISH identified EBV-infected lymphoid cells in two of 17 sites without morphologic evidence of BLPD. These data demonstrate the utility of ISH for detecting EBV genome in this setting and provide further evidence for the etiologic role of EBV in the pathogenesis of BLPD.