A monoclonal immunoblastic sarcoma in donor cells bearing Epstein-Barr virus genomes following allogeneic marrow grafting for acute lymphoblastic leukemia.

A patient undergoing marrow grafting for acute lymphoblastic leukemia from his partially HLA-mismatched sister displayed a widely disseminated immunoblastic sarcoma at autopsy. The tumor was monoclonal by immunoglobulin light-chain staining. Blot hybridization analysis, using a cloned highly polymorphic locus in human DNA as a probe, showed the tumor to be of donor-cell origin. Cytogenetic analysis also demonstrated donor-cell origin. Blot hybridization analysis demonstrated Epstein-Barr virus (EBV) genomes in the tumor. By contrast, reexamination of material from a previously reported case of a donor-type relapse showed no evidence of EBV DNA. In neither case was there evidence of cytomegalovirus DNA. This study documents the association of EBV with a malignant, monoclonal B-cell lymphoma arising in a marrow graft recipient. We conclude that DNA restriction fragment length polymorphisms can be used to prove the origin (donor or host) of neoplastic relapse following allogeneic marrow grafting. Further, cell types different from those of the original leukemia may be involved.