Pediatric central nervous system posttransplant lymphoproliferative disorder.

Post-transplant lymphoproliferative disorder complicates approximately 1% of all renal transplants. The usual site of occurrence is within the abdomen, thorax, allograft, or head and neck. Central nervous system involvement is uncommon but, when present, occurs in isolation, sparing other organ systems. Few articles in the radiology literature have focused on the acute and follow-up central nervous system findings of the disease, especially in children. Because the clinical and imaging characteristics of central nervous system post-transplant lymphoproliferative disorder overlap those of infection and primary central nervous system lymphoma and the fact that untreated posttransplant lymphoproliferative disorder has a poor prognosis, it is important to maintain a high index of suspicion for this disorder so that appropriate treatment can be instituted.