B-cell lymphoma of recipient origin 9 years after allogeneic bone marrow transplantation for T-cell acute lymphoblastic leukaemia.

A 25-year-old woman developed an immunoblastic lymphoma 9 years after HLA-identical allogeneic bone marrow transplantation for T-cell acute lymphoblastic leukaemia in second remission. The B-cell origin of the second malignancy was confirmed by gene rearrangement studies. Despite continued donor engraftment, two separate genotypic analyses identified the lymphoma to be of recipient origin. This is the longest latency of a post-transplant recipient lymphoma yet reported and illustrates that recipient B-cells may survive the transplant conditioning regimen and undergo malignant transformation in the presence of donor haemopoiesis.