Tumor lysis syndrome associated with reduced immunosuppression in a lung transplant recipient

Tumor lysis syndrome usually occurs after initiation of chemotherapy or radiation therapy in cancer patients with a moderate to high tumor burden. To our knowledge, the occurrence of this syndrome after discontinuation or reduction of an immunosuppresive, sive regimen has not been reported in the literature. We describe a patient who had undergone lung transplantation and who was receiving immunosuppression and experienced an episode of acute pancreatitis. During the course of the work-up, the patient was found to have a B-cell lymphoma (posttransplantation lymphoproliferative disease). His tacrolimus dosage was decreased, and azathloprine was discontinued. The patient subsequently developed tumor lysis syndrome. Other than the decrease in immunosuppression, we found no other factor that could have accounted for this syndrome.