WHO diagnostic criteria for CMML44 *
Distinction of promonocytes from more mature but abnormal monocytes is key to distinguishing CMML from AML. Cytogenetics: clonal cytogenetic abnormalities in 20%-40%. The most frequent include +8, −7/del(7q), del(12p), and del(20q).40,44,48 Although most myeloid neoplasms associated with isolated isochromosome 17q will meet the criteria for CMML, others may be more appropriately categorized as MDS/MPN, unclassifiable. Some authorities argue that they are sufficiently unique to be considered as a separate entity.49 Molecular genetic: NRAS or KRAS, RUNX1, TET2, CBL, ASXL1 mutated in 20%-50%35,50–53 ; less commonly, EZH2 (11%-13%)42,53 ; IDH1/IDH2, JAK2, NPM1 (<10%)31,53,54 ; and, infrequently, FLT3, CEBP, WT1, and PTPN11 mutations.31,35
†Blasts include myeloblasts, monoblasts, and promonocytes.
