Should oligomonocytic CMML be classified as an independent disease entity?

The 2022 WHO Classification revised the diagnostic criteria of CMML and included the variant, formerly known as oligomonocytic CMML (O‐CMML), into the CMML disease. CMML is currently subtyped into MD‐CMML and MP‐CMML. In a recent study, Castaño‐Díez et al. showed that the newly included O‐CMML has unique clinical features and is an independent favourable risk factor, and proposed to view O‐CMML as an independent subtype of CMML, parallel to MD‐CMML and MP‐CMML. Commentary on: Castaño‐Díez et al. Characteristics and long‐term outcome in a large series of chronic myelomonocytic leukaemia patients including 104 formerly referred to as oligomonocytic. Br J Haematol 2024;204:892‐897. [ABSTRACT FROM AUTHOR]