m5 is a subtype of acute myeloid leukemia called acute monocytic leukemia. Leukemia is a relatively common disease of the blood system. It is divided into acute and chronic. Acute can be further divided into acute myeloid leukemia and acute lymphoblastic leukemia. m5 is a type of acute myeloid leukemia. Acute myeloid leukemia is divided into eight types: m0 to m7. The m5 leukemia is divided into the following two subtypes: ① undifferentiated type (M5a): ≥80% of primitive monocyte type I + II (NEC) in bone marrow; ② partially differentiated type (M5b): >30% of primitive and naïve monocytes (NEC) and <80% of prokaryotic monocytes (type I + II) in bone marrow. The main manifestations of m5 leukemia are hepatosplenomegaly and enlarged lymph nodes, which are caused by monocyte proliferation. Chemotherapy and allogeneic transplantation are the treatment options. It is recommended to consult a doctor in time and follow the doctor's instructions to standardize the treatment.