According to guideline of WHO classification system of Myeloid malignancies, Chronic Myelomonocytic Leukemia (CMML) is observed as the most frequent entity among myeloproliferative/ myelodysplastic syndromes. The blast cells observed in the peripheral and marrow was considered as the major prognostic factor identified at that time. Cytogenetic prognostications are not much clear. We studied a patientwith CMML with a successful conventional cytogenetic analysis at diagnosis. Combined results of Fluorescence In Situ Hybridization and Multi Color banding technique revealed a new variant and novel t(12;15) along with duplication of chromosome 1 in CMML. The patient showed BCR-ABL negative in FISH assay result and positive for JAK2 mutation study. Patient achieved remission without any treatment. This is potentially suggestive of a novel favorable-risk translocation in CMML.
