Question category: Haematology
A 60 year old male presents with fatigue, night sweats and weight loss. He has also noticed his stomach feeling bloated and distended. On examination there is evidence of splenomegaly. Bloods reveal a normochromic, normocytic anaemia, elevated white cell counts and slightly elevated platelets. A blood film reveals myeloid cells are various stages of development. Cytogenetic analysis and PCR reveals the Philadelphia chromosome and BCR ABL. What is the most likely diagnosis?