Posttransplant lymphoproliferative disorder is a rare but well-known
complication in solid organ or hematopoietic transplant recipients
secondary to immunosuppression. It can range from a cellular hyperplasia
to a classic lymphoma. We describe a case of a nine-year-old male with
Barth syndrome and a history of cardiac transplantation who developed
plasmacytoid EBV-negative PTLD, an extremely rare entity in the
pediatric population, and the evolvement of his PTLD to a more
aggressive plasma cell neoplasm.