Posttransplant Lymphoproliferative Disorder in Children: A 360-degree Perspective

Posttransplant lymphoproliferative disorder (PTLD) is the most common malignancy that can occur after organ transplant in children. PTLD arises because the patient's immune system has been suppressed to protect the graft and may fail to provide an adequate immune check for transformed malignant or premalignant lymphocytes. PTLD risk factors and pathogenesis are not completely understood; however, Epstein-Barr virus is identified in many patients with PTLD and may contribute to its evolution. PTLD is a clinical challenge because the biologic behavior and clinical manifestations are diverse, and there is no standardized treatment.Treatment options include reduction of immunosuppression therapy, chemotherapy, radiation therapy, and surgical resection of localized lesions, depending on factors including the type and extent of disease, whether the patient has positive test results for the Epstein-Barr virus, and patient comorbidities. A multidisciplinary approach is essential for the appropriate management of PTLD. Diagnostic imaging modalities such as radiography, US, CT, MRI, and PET are essential in diagnosis, assessment of therapeutic response, and monitoring of this heterogeneous disease entity. When imaging findings are suggestive of PTLD, prompt tissue biopsy to identify the PTLD subtype is essential for appropriate treatment. It is important to know the proper indications and limitations of different diagnostic imaging techniques in the management of PTLD. In addition, familiarity with the imaging features of PTLD and its mimics narrows the differential diagnosis and may facilitate decision making about patient treatment. (C) RSNA, 2019 center dot radiographics.rsna.org