Concomitant BCR::ABL positive chronic myelogenous leukemia and Ph-negative myeloproliferative neoplasm – case reports of a single centre institution

Abstract

Chronic myeloid leukemia (CML) is defined by the BCR::ABL1 fusion resulting from t(9;22)(q34;q11). According to the 5th edition of the WHO classification of Haematolymfoid Tumours it belongs to the group of myeloproliferative neoplasms (MPN) with polycythaemia vera, essential thrombocythaemia, primary myelofibrosis, chronic neutrophilic leukaemia, chronic eosinophilic leukemia, juvenile myelomonocytic leukaemia and myeloproliferative neoplasms, not otherwise specified. Rare cases with co-occuring BCR::ABL1 positive CML and Ph negative MPN have been identified. We present a detailed description of clinical, cytomorphological and molecular characteristics of 4 cases of BCR::ABL1 positive CML patients with coexiting Ph negative MPN with driver mutations.