Haema 2012; 3(2): 109-116
by Nora Viniou, Panagiotis Diamantopoulos
1st Dept of Internal Medicine, University Medical School of Athens, “Laiko” General Hospital
Abstract
The 2008 World Health Organization classification of myeloid neoplasms includes the category of myelodysplastic/myeloproliferative neoplasms (MDS/MPN). This category of rare clonal myeloid neoplasms encompasses those that show overlapping myeloproliferative and myelodysplastic features at initial presentation. There are four main subcategories of MDS/MPN, chronic myelomonocytic leukemia (CMML), atypical chronic myeloid leukemia (aCML), BCR-ABL-negative CML, juvenile myelomonocytic leukemia, as well as unclassifiable MDS/MPN. At present, no cytogenetic or molecular genetic abnormalities are specific to an MDS/MPN subtype. However clonal karyotypic abnormalities can be encountered in these neoplasms. The diagnosis and classification of MDS/MPN relies on the careful integration of clinical, morphologic, and immunophenotypic features, while genetic testing plays more of an exclusionary role. CMML is the most common of the MDS/MPN subtypes. It is subclassified into CMML-1 and CMML-2, a distinction that is based on the blast percentage and is prognostically significant. The differential diagnosis of CMML is vast and includes infectious and inflammatory dis- eases as well as neoplastic diseases presenting with monocytosis. Conservative treatment of CMML is highly heterogenous ranging from a “watch and wait strategy” or supportive care to cytoreductive treatment (cytarabine, etoposide). All agents that have been used in the treatment of MDS have also been used to treat CMML. Allogenic hematopoietic stem cell transplantation remains the only curative option.