Primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is an extranodal non-Hodgkin lymphoma (NHL) confined to the brain, leptomeninges, eyes, or spinal cord. Most PCNSLs are diffuse large B-cell lymphoma (DLBCL; 90%), with the remainder consisting of T-cell lymphomas, poorly characterized low-grade lymphomas, or Burkitt lymphomas. The molecular pathogenesis of PCNSL is now better understood. The B-cell receptor (BCR) signaling axis with its downstream target, NF-kappa B, is affected by frequent recurrent mutations, mainly in MYD88, CD79B and, less frequently, CARD11, and TNFAIP3. Recurring chromosomal losses affect the 6q, 6p21.32 (HLA locus) and 9p21 (CDKN2A locus) regions.