MLL-AF4 gene rearrangement in a child with Epstein-Barr virus-related posttransplant B-cell lymphoma.

Recipients of solid organ allografts are known to be at increased risk of developing Epstein-Barr virus-related posttransplant lymphoproliferative diseases. A 28-month-old boy who had received a heterotopic liver transplant presented with lymphadenopathy in the abdomen, multiple nodules in the liver, and bilateral renal infiltration 19 months after transplantation. He was diagnosed with a Burkitt-like lymphoma based on bone marrow examination and the finding that the blastic cells in bone marrow were EBER-1 positive. Cytogenetic analysis of the bone marrow cells showed an MLL-AF4 rearrangement. He was treated with a combined chemotherapy regimen. He has been in continuous complete remission for 15 months now.