Histologic transformation of follicular lymphoma after allogeneic bone marrow transplantation.

A 38-year-old man with refractory follicular lymphoma underwent allogeneic BMT from an HLA-identical sibling donor. He had generalized lymphadenopathy, hepatosplenomegaly and lymphoma infiltration of the marrow, all of which disappeared within 3 months following transplantation. Six months post-transplant, progressive hepatomegaly developed in the absence of splenomegaly and lymphadenopathy, and he died from hepatic failure. Autopsy disclosed diffuse large B cell lymphoma of the liver, into which the follicular lymphoma had transformed. Future issues to be investigated should include the optimal timing of allogeneic BMT for low-grade lymphomas.