A Case of AML1-ETO Positive Acute Myeloid Leukemia Morphologically Similar to Chronic Myelogenous Leukemia.

BACKGROUND: The goal was to study the role of the morphology, immunophenotype, karyotype and fusion gene expression in a patient with diagnosis of AML1-ETO positive acute myeloid leukemia.

METHODS: A case of AML1-ETO positive acute myeloid leukemia morphologically similar to chronic myelogenous leukemia was reported. The results of the morphology, immunophenotype, karyotype and fusion gene expression were analyzed by reviewing relevant literature.

RESULTS: The patient was a young boy, at the age of 13, with clinical manifestations of intermittent fatigue and fever. Blood routine: White blood cell 142.6 x 109/L, Red blood cell 0.89 x 1012/L, Hemoglobin 41 g/L, Platelet 23 x 109/L, primitive cells account for 5%. Bone marrow smear: Granulocyte system hyperplasia is obvious, visible at each stage, primitive cells account for 17%, eosinophils, basophils, and phagocytic blood cells were observed. Flow cytometry showed myeloid primitive cell population was 4.14%, immature and mature granulocytes cell population was 85.22%, and eosinophil cell population was 0.61%. The results showed that the proportion of myeloid primitive cell was high, the expression of CD34 was enhanced, the expression of CD117 was partially absent, the expression of CD38 was weakened, the expression of CD19 was weak, and a few cells expressed CD56, and the phenotype was abnormal. The proportion of granulocyte series increased and the nucleus shifted to the left. The proportion of erythroid series was decreased, and the expression of CD71 was weakened. The results of fusion gene showed AML1-ETO positive. Karyotype analysis showed clonogenic abnormality t(8;21)(q22;q22).

CONCLUSIONS: The peripheral blood and bone marrow images of patients with t(8;21)(q22;q22) AML1-ETO positive are the manifestations of chronic myelogenous leukemia, suggesting that cytogenetics and molecular genetics play an irreplaceable role in the diagnosis of acute myeloid leukemia, and the comprehensive diagnostic efficiency is significantly better than that of morphology.