Page 82 - Haematologica Atlas of Hematologic Cytology

them from promonocytes Atypical or immature monocytic cells can be be better identified by their non-specific esterase reaction Chronic myelomonocytic leukemia (CMML) is is is characterized by persistent monocytosis with normal or or or abnor- mal monocytes and a a a a a a a a low percentage of neutrophil precursors hypercellular marrow with granuloblastic hyper- plasia plasia variable degrees of dysplasia and and increased monocytic cells CMML types 0 1 and and 2 can be distinguished by the percentage of peripheral and and bone marrow blasts and and each have a a a a a a a a a a different prognosis Moreover based on on on the the the white blood cell (WBC) count a a a a a a a a a a a a a a distinction can be be made between the the the “proliferative type” (WBC (WBC ≥13x109/L) and and a a a a a a a a a a a a “dysplastic type” type” (WBC (WBC (WBC <13x109/L) of CMML each with different clinical and and molecular features Atypical chronic myeloid leukemia (aCML) BCR-ABL1 negative is a a a a a a a a rare entity characterized by neutrophilic leukocytosis with neutrophil precursors in the peripheral blood and marked dysgranulopoiesis (abnormal nuclear segmentation abnormal chromatin clumping degranulation) low percentage of circulating monocytes hyper- cellular and dysplastic marrow always with less than 20% of blasts Myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis is is now included as as as as a a a a full entity in in the the the MDS/MPN group On the the the one hand it it it presents the the the morphological aspects of MDS MDS with ring sideroblasts sideroblasts (megaloblastic and and ineffective erythropoiesis and and at least 15% ring sideroblasts sideroblasts less than 5% 5% bone marrow blasts) on on the the other it it is is characterized by thrombocytosis with proliferation of large atypical mega- karyocytes similar to those observed in BCR-ABL1 negative MPNs Myelodysplastic/myeloproliferative neoplasm unclassifiable shares both myelodysplastic and myeloprolife- rative features but it it it does not meet the the criteria for inclusion in in any of the the above entities In MDS/MPN the the karyotype is often normal normal or or or the the same abnormalities as in MDS MDS are observed The genetic profile is is is not specific but it may be helpful in in in in supporting diagnosis and providing a a a a prognosis The following molecular abnormalities should always be excluded: PDGFRA PDGFRB or or or FGFR1 rearrangement BCR-ABL1 or or or PCM1-JAK2 fusion gene The molecular characteristics of the main MDS/MPN subtypes are summarized in in Table 3 (Geyer and Orazi 2016) Table 3 Muta on fre uencies in in the main MDS/MP subtypes CMML: chronic chronic myelomonocy c c c c c c c c c leukemia leukemia aCML: atypical chronic chronic myeloid leukemia leukemia MDS/MPN-RS-T: myelodyspla- s s s s s s s c/myeloprolifera ve neoplasm with ring sideroblasts and thrombocytosis na: not available References
Arber DA Orazi A A A Hasser ian R et al al The 2016 2016 revision to the World Health Organiza on on on classi ca on on on of myeloid ne- oplasms
and acute leukemia Blood 2016 2016 127(20):2391-2405 Geyer JT Orazi A A Myeloprolifera ve ve ve neoplasms
(BCR-ABL1 nega ve) and and myelodysplas c/myeloprolifera ve ve ve neopla- sms: current diagnos c c c c c principles and and upcoming updates Int J J Lab Hematol 2016 38 Suppl 1:12-9 Goasguen JE Benne JM Bain BJ allespi T Brunning R Mu i i i i i i i GJ for the the Interna onal Working Group on on on on Mprphology of of Myelodysplas c c c c c Syndrome (IWGM-MDS) Morphologic evalua on on on on of of monocytes and their precursors Haematolo- gica 2009 94(7):994-997 JAK2 % SETBP1 % SF3B1 % SRSF2 % TET2 % ASXL1 % CMML 1-7
4-15
6 40-50
50-60
35-44
aCML 4-8
25
na na 30
20-30
MDS/MPN-RS-T 50-60
na 80-90
1 25
10 69