Clinical and pathologic features of the 3 identified types of PTLD involving the CNS. (A) Preoperative T1-weighted postcontrast magnetic resonance imaging and hematoxylin and eosin–stained sections from representative patients with sporadic PCNS-LBCL–like, systemic Ras-driven, and EBV-driven CNS-limited PTLD-CNS showing intraparenchymal mass lesions with contrast enhancement and significant edema in the surrounding white matter. Ki-67 LI is shown. (B) Summary of clinical and pathologic features of the multiinstitutional cohort of patients with PTLD-CNS.