CNS relapse in DLBCL: a calculable risk?

In this issue of Blood, Ollila et al(1) address a challenging problem: Can the risk for central nervous system (CNS) relapse in patients with diffuse large B-cell lymphoma (DLBCL) be predicted better on a molecular basis? The authors found that most tumors with CNS recurrence are well defined molecularly and fall into 2 categories. The most frequent is the hc-MCD subtype, based on MYD88L265P and CD79B mutations, which molecularly resembles primary central nervous system lymphoma (PCNSL). Its association with some extranodal disease sites suggests that the molecular underpinning is the major factor driving the increased risk of CNS invasion. The second subgroup encompasses high-grade tumors characterized by double-hit biology or TP53 mutations, which frequently exhibit high-grade B-cell lymphoma signature on gene expression profiling.

Automated summary

The study identified two subtypes of DLBCL tumors with CNS recurrence: the hc-MCD subtype resembling PCNSL, and the high-grade tumors characterized by double-hit biology or TP53 mutations.