This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'In acute myeloid leukemia, Auer rods are numerous in: September 2009 \nSelect and explain. \nA. M2, B. M3, C. M4, D. M5', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B: M3 The diagnosis of AML is based on the presence of at least 20% myeloid blasts in the bone marrow. Myeloblast have delicate nuclear chromatin, two to four nucleoli, and more voluminous cytoplasm than lymphoblasts. The cytoplasm often contains fine, peroxidase-positive azurophilic granules. Auer rods, distinctive needle like azurophilic granules, are present in many cases; they are paicularly numerous in AML with the t(15;17) (acute promyelocytic leukaemia-M3).', 'role': 'assistant'}]