The cells of lentigo have morphological abnormalities, varying cell size, unbalanced nucleoplasmic development, and some cells have sparse nuclear chromatin, vacuoles in the cytoplasm, or adult cell rupture, but the morphological changes in lentigo cells are not characteristic, and the diagnosis of lentigo can not be made from the cellular morphology. Chronic granulocytic leukemia (lentigo) is often diagnosed through the following aspects: 1. Bone marrow hyperplasia: Bone marrow hyperplasia is obvious to extremely active, dominated by granulocytes, in which neutrophilic neutrophilic, late juvenile and rod-shaped nucleated granulocytes are obviously increased, and erythrocytes are relatively reduced. Megakaryocytes are normal or increased and decreased in late stage. Neutrophil alkaline phosphatase (NAP) activity is reduced or negative. 2. Blood picture: leukocyte count is obviously increased, neutrophils are significantly increased, with neutrophilic neutrophilic, late juvenile and rod-shaped nucleated granulocytes predominating, primitive cells are generally 1%~3%, not more than 10%; eosinophilic basophilic granulocytes are increased, platelets are mostly at the normal level in the early stage of the disease, and platelets gradually decrease in the late stage of the disease, and anemia may appear. 3. Blood biochemistry: serum and urinary uric acid concentration increases, serum vitamin B12 concentration and vitamin B12 binding capacity increase significantly, and is proportional to the degree of leukemia cell increase. 4. Cytogenetic and molecular biological changes: Ph chromosome, i.e. Philadelphia chromosome, is the characteristic chromosome of chronic granulocytic leukemia, and Ph chromosome and BCR/ABL fusion gene are the confirmatory indicators of lentigo. Lentigo cannot be determined from cell morphology. Do not judge or diagnose on your own based on one test result, but consult a doctor in time, who will analyze and diagnose the disease according to the specific situation.