Chronic Myelomonocytic Leukemia in Qatar, Single Institute Experience

• Published in: Blood 2020-11, Vol.136 (Supplement 1), p.38-38
• Main Authors: Kohla, Samah, Elkourashy, Sarah, Abbas, Feryal, Akiki, Susanna Jane, Yassin, Mohamed A
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2020-134871

Background Chronic myelomonocytic leukemia (CMML) is a rare de novo clonal hematopoietic stem cell disorder with overlapping features of myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN). The diagnosis is challenging and carrying risk for leukemic transformation. The median age at CMML diagnosis is ~71‐73 years, with a male preponderance. According to the 2016 World Health Organization (WHO) classification of myeloid neoplasms, CMML is characterized by the presence of sustained (>3 months) peripheral blood (PB) monocytosis (≥1 × 109/L; monocytes ≥10% of white blood cell count) along with dysplastic features in the bone marrow (BM). < 20% blasts/blasts equivalent in the PB and BM. It has recommended categorization of CMML into “proliferative” (MPN‐CMML) and “dysplastic” (MDS‐CMML) sub‐types; based on a total leukocytic count (TLC) (of ≥13 × 109/L for MPN‐CMML). Also, based on PB and BM blast %, CMML can be sub‐classified into three categories; (a) CMML‐0 (20 cm in craniocaudal length). According to the TLC, 8 were myeloproliferative (CMML/MP) and 4 were myelodysplastic CMML. 4 of our patients were below 40 years (classified as young adults as per WHO) and all were of the proliferative type. The flow cytometry of PB and/or BM was done to 11 patients. The monocytic cells were characterized by co-expressing CD14 and CD64 and showed aberrant expression of CD56 on 5 patients. According to the morphology of the BM, one case was described as MDS/MPN or MPN, and the rest of the cases