Basophilic leukemia (BL) was first reported by Goachim et al. in 1906. Basophils are the main components of blood and bone marrow. In addition to the clinical manifestations of acute leukemia, patients also have urticaria, skin flushing and numerous gastrointestinal symptoms caused by hyperhistamineemia. There are two types of BL: one is acute at onset, and the other is basophilic disease in the late stage of chronic CML. Some patients with acute myeloid and monocytic leukemia have t(6;9)(p23;q34) abnormalities, and the number of basophils in the bone marrow but not in the peripheral blood increases. CML patients have t(9;22)(q34;q11) abnormalities. Both diseases have abnormalities in chromosome 9 (q34) and an increase in basophils, which suggests that the breakpoint gene of chromosome 9 may affect the production of basophils. Peterson et al. conducted ultrastructural analysis of leukemic primitive cells in 455 patients with acute leukemia and found 8 cases of acute basophilic leukemia, accounting for less than 2% of acute leukemia. However, Quattrin's statistics showed that this disease accounted for 4.5% of acute leukemia in 2152 cases of hematological malignancies admitted to the Naples Hospital in Italy from 1959 to 1973. This disease is characterized by the appearance of immature basophils in the blood (more than 1/3 of the total white blood cells) and their continued presence throughout the course of the disease.