A tale of two mantle cell lymphomas

Abstract

In his lecture series, A Course on English Literature, delivered in 1966 at the University of Buenos Aires, Jorge Luis Borges remarked, “Dickens lived in London. In his book A Tale of Two Cities, based on the French Revolution, we see that he really could not write a tale of two cities. He was a resident of just one city: London.” Comparably, over the past 2 decades, dozens of papers have been published describing the 2 subtypes of mantle cell lymphoma (MCL): classical and leukemic, nonnodal. Yet, in the clinical world, there has only been 1 MCL. In this issue of Blood, Clot et al describe the development and validation of a nanostring-based assay that can accurately distinguish between classical and nonnodal MCL, which, in combination with genomic complexity, can provide important prognostic information.1 The biological basis for the differences between MCL subtypes are illuminated in a recent Blood review by Puente et al,2 and the differences are significant. Although both subtypes share a reliance on cell-cycle dysregulation, they arise from distinct cells of origin through different molecular pathways and result in diseases with different presentations and natural histories until problems with genomic instability result in a convergence of the 2 subtypes, frequently seen as the blastoid phenotype and treatment resistance (see figure).