Post-Transplantation Lymphoproliferative Disorder of the Central Nervous System: Spectrum of Imaging Findings

PTLD is a rare but known complication after organ transplantation. It represents a spectrum of diseases, ranging from premalignant lymphoid hyperplasia to aggressive lymphoma. The distribution of PTLD is dependent on several risk factors, including the type of organ transplantation, the intensity of immunosuppressive therapy, and the age of the patient. PTLD involving the CNS often occurs in isolation and is not typically associated with systemic involvement of PTLD. The imaging and pathologic features of CNS PTLD are similar to those of PCNSL, seen in patients with HIV. Several imaging patterns associated with CNS PTLD include ≥1 peripherally enhancing intraparenchymal masses and nodular leptomeningeal enhancement. Imaging plays a crucial role in disease diagnosis, guiding biopsy and monitoring disease response following therapy. The purpose of this pictorial essay is to review the pathologic features of CNS PTLD and to illustrate the spectrum of imaging findings of CNS PTLD with a variety of case examples.