[Lymphoproliferative disorders and lymphomas in immunocompromised patients]

Lymphoproliferative disorders and lymphomas arising in the setting of immunodeficiency constitute a highly heterogeneous group of entities whose diagnostic approach has evolved substantially with the 2022 WHO classification. This classification proposes a continuum ranging from reactive hyperplasias to bona fide lymphomas, organized according to morphological, virologic, and genetic criteria rather than solely by the underlying cause of immunodeficiency. It distinguishes lymphoid hyperplasias, polymorphic lymphoproliferations, EBV-positive muco-cutaneous ulcer, and lymphomas, and separately identifies lymphoproliferations associated with inborn errors of immunity. The 2022 ICC adopts a more clinically oriented perspective and preserves the concept of post-transplant lymphoproliferative disorder, considered relevant for patient management. This review compares these two frameworks across major clinical settings, including organ transplantation, non-transplant iatrogenic immunosuppression, constitutional immunodeficiencies, and HIV infection. Overall, it highlights the considerable morphological and biological diversity of these entities and underscores the need for precise, context-adapted classification to ensure accurate diagnosis and optimal patient care.