The concomitant occurrence of JAK2617F mutation and BCR/ABL translocation is a rare event. It is unclear if this is a result of the clonal evolution or a separately emergence of two clones and if it could lead to the progression to a more aggressive phase of the disease. We present the case of a 61-year-old man diagnosed and treated for polycythaemia vera for 7 years, which evolved into chronic myeloid leukemia BCR/ABL positive and with JAK2617F mutated clone, that became dominant after an effective treatment with Imatinib.

Abbreviations:WHO – World Health Organisation; CML – chronic myeloid leukemia; MPN – myeloproliferative neoplasms; PCR- polymerized chain reaction; TKI – tyrosine kinase inhibitors; PV – polycythemia vera; ET- essential thrombocythemia; PMF – primary myelofibrosis; ESR – erythrocyte sedimentation rate; WBC – white blood cell count; LDH – lacticodehydrogenase; ALP – alkaline leucocyte phosphatise