Reconceptualizing the framework for categorizing the heterogeneous spectrum of lymphoproliferation in pediatric posttransplant lymphoproliferative disorders (PTLD). Traditional PTLD classification is based on morphological features stratified as nondestructive, polymorphic, monomorphic, and classical Hodgkin lymphoma (CHL) PTLD. This revised stratification highlights the heterogeneity of monomorphic PTLD and demarcates a threshold beyond which quintessential EBV-driven lymphoid hyperplasia/neoplasia transforms into malignant lymphoma. EBV⁺ DLBCL in particular straddles the threshold between quintessential PTLD and posttransplant lymphoma. HGBL NOS, high-grade B-cell lymphoma, not otherwise specified and other gray-zone, Burkitt-like mature B-cell lymphomas; PLASMA CELL, plasma cell neoplasm; T/NK CELL, T/NK-cell lymphoma; TX, transplant. Ovals with purple borders indicate entities that are typically EBV positive; ovals with blue borders indicate entities that are often EBV negative. Reproduced from El-Mallawany and Kamdar²⁰ with permission.