WHO 2022 Large B-cell lymphomas (LBCL) of immune-privileged sites is a new umbrella term introduced in WHO-HAEM5 to acknowledge common biological features of a group of aggressive B-cell lymphomas that arise as primary tumours in the central nervous system (CNS), the vitreoretinal compartment, and the testes of immunocompetent patients.

This new entity now combines the previous entity of primary DLBCL of CNS with DLBCL of the vitreoretina and testis that were previously included among DLBCL, NOS. They arise in immune sanctuaries created by their respective anatomical structures (e.g., the blood-brain, bloodretinal, and blood-testicular barriers), and immune regulation systems within their respective primary sites, and share immunophenotypic and molecular features. Information on this group of tumours is rapidly accruing: it appears that some lymphomas arising at other distinct sites such as the breast and skin share some of these features, and thus, this group of ‘immune-privileged lymphomas’ might expand in future classifications.

CNS lymfoom

Er is weinig literatuur mbt behandelschema bij recidief DLBCL met wederom CNS lokalisatie. Schema's zijn over het algemeen dosis- en tijds-intensief, met middelen die de BBB kunnen passeren, zoals MTX en HD ARA-C. Als in CR dan heeft het de voorkeur om te consolideren met een autologe; conditionering schema's in primair CNS zijn middelen met carmustine, thiotepa of busulfan (en die worden derhalve ook vaak bij secundaire CNS lymfomen gebruikt).

Recente trial: Lancet Haematol 2021: MARIETTA trial in sec CNS lymfoom, 6 kuren wv 3x MATRIX (R, MTX 3,5g/m2, cytarabine 2dd 2 g/m2 ged 2dg, thiotepa 30 mg/m2) en 3x RICE (R, etoposide 100 mg/m2 dag 1-3 + ifosfamide 5 g/m2 dag 2, carboplatin . Autologe met (carmustine 400 mg/m2 day -6 en thiotepa 5 mg/kg 2dd days -5 and -4). Respons in n=75, 1y PFS 58%, 2y OS 46%. NB overigens ook nog met IT therapie.

Kuurschema's DHAP (+HD-MTX?) vs R-MBVP ARA-C vs MATRIX-RICE

- cytarabine in DHAP minder dan in primair CNS lyfmoom schema of matrix/ric )4 vs 8 g/m2)

- MTX niet in DHAP, wel in andere schema's

- thiotepa niet in DHAP/primair CNS schema, wel in MATRIX/RICE

- systemisch: steroïoden, rituximab + 1-2 middelen

Conditionering BEAM vs Car/Thio

- geen 'systemische' drug in car/thio

- minder carmustine in BEAM, maar wel nog lage dosis cytarabine