Mixed phenotype (T/B/myeloid) extramedullary blast crisis as an initial presentation of chronic myelogenous leukemia

Diagnosis of extramedullary blast crisis should be suspected in patients with leukocytosis and extramedullary blast proliferation. In this case study, we diagnosed extramedullary blast crisis accompanied by chronic phase of CML in the bone marrow. To our knowledge, this is the first reported case of extramedullary blast crisis as the initial presentation of CML with T/B/myeloid mixed phenotype. Other unusual features associated with this case are also discussed.