All of the following acute myeloid leukemia are diagnosed regardless of blast count except: (A) AML with t(8;21), (B) AML with t(15;17), (C) AML with t(16;16), (D) AML with t(1;9)
Answer is D. WHO classification mandates diagnosis of AML only when >20% blasts are present in the marrow. However, in the following three scenarios, this is overruled and AML may be diagnosed even if blast count is <20%.

AML with t(8;21)
AML with t(15;17)
AML with inv (16) or t(16;16)