Chronic leukemia is more common in adults, with chronic myeloid leukemia (CML) being the most prevalent type in China. Its incidence ranks third, following acute myeloid leukemia and heat stranguria.

bubble_chart Clinical Manifestations

The onset is insidious, and there may be no symptoms in the early stages. It is often discovered incidentally during peripheral blood tests for other reasons or when seeking medical attention for a mass in the left upper abdomen. The disease predominantly occurs between the ages of 20 and 40.

1. Systemic symptoms mainly manifest as hypermetabolism, including lack of strength, low-grade fever, profuse sweating, night sweating, weight loss, and nervous tension.

2. Splenomegaly is a prominent feature of this disease. The enlargement may reach the level of the umbilicus or even extend into the pelvis, with a firm texture, notches, and no adhesions. If splenic infarction or perisplenitis occurs, there may be pain in the splenic area accompanied by a friction rub. Hepatomegaly is usually mild. Tenderness is often present in the middle and lower parts of the sternum.

bubble_chart Auxiliary Examination

1. The total white blood cell count in the blood picture is significantly increased, often exceeding 100×10⁹/L, and can even reach as high as 1000×10⁹/L. The blood smear differential shows that the majority are neutrophilic myelocytes, metamyelocytes, and band cells. The percentage of myeloblasts is less than 5%, and the combined count of myeloblasts and promyelocytes does not exceed 10%. Eosinophils and basophils are elevated. Red blood cells and hemoglobin show mild to grade II reduction, and a few nucleated red blood cells may appear in the blood smear. Platelets may be normal or increased in the early stage, but gradually decrease in the advanced stage.
2. The bone marrow picture shows extreme hypercellularity, predominantly with granulocytic hyperplasia. The cell differential is similar to that of the blood smear, with frequent elevation of eosinophils and basophils. The erythroid series is relatively reduced at all stages. Megakaryocytes are increased or normal but decrease in the advanced stage. Cytochemical staining reveals reduced or completely negative activity of neutrophil alkaline phosphatase (NAP), which may rise to normal levels after effective treatment.
3. Chromosomal analysis reveals the presence of the Philadelphia (Ph) chromosome, t(9;22), in over 90% of patients. This deleted chromosome 22 with a shortened long arm is the Ph chromosome. Patients who are Ph chromosome-negative have a poorer prognosis than those who are positive, often surviving less than 1 year. Therefore, chromosomal analysis holds certain value in the diagnosis, differential diagnosis, and prognosis of chronic myeloid leukemia.
4. Blood generation and transformation: Serum vitamin B12 concentration and vitamin B12 binding capacity are significantly elevated. Serum uric acid concentration is often increased.

bubble_chart Diagnosis

Typical cases present with marked splenomegaly accompanied by abnormal elevation of white blood cells, immature granulocytes at various stages in the blood smear, and increased eosinophils and basophils. The bone marrow findings resemble the peripheral blood picture, with reduced NAP activity. The presence of the Ph chromosome confirms the diagnosis.

If the patient lacks obvious clinical manifestations or only exhibits symptoms such as low-grade fever, lack of strength, profuse sweating, and weight loss, with myeloblasts plus promyelocytes ≤5% in the blood and ≤10% in the bone marrow, it is classified as the chronic phase. During disease progression, the appearance of unexplained fever, worsening anemia and bleeding, bone pain, progressive splenomegaly, thrombocytopenia, resistance to conventional anti-CML therapy, and blasts >10% in both blood and bone marrow indicates the accelerated phase. When the blood and bone marrow findings and clinical manifestations resemble acute leukemia, it is considered the blast crisis phase. After transformation to blast crisis, patients often succumb to infection, hemorrhage, or衰竭 within 2–6 months.

bubble_chart Treatment Measures

1. Chemotherapy: Commonly used drugs include busulfan, dibromomannitol, and nitrogen mustard drugs, with busulfan being the preferred choice. In China, indirubin extracted from Chinese medicinals Indigo can also be used.

2. Radiotherapy: Deep X-ray irradiation is suitable for cases with progressive disease, a rapid increase in white blood cell count, and significant enlargement of the spleen and lymph nodes.

3. Splenectomy: This can delay the onset of blast crisis.

bubble_chart Differentiation

In the differential diagnosis, the more common condition is the leukemoid reaction, whose disease causes are mostly infections and malignant tumors. The total white blood cell count is mostly between 50–100×10⁹/L, with rare cases of abnormally high levels. Neutrophils often exhibit toxic granules and vacuoles, NAP activity is significantly increased, and the bone marrow morphology shows no leukemic cell changes. The leukemoid reaction may disappear after the removal of the primary lesion. Additionally, myelofibrosis can also present with significant splenomegaly, immature granulocytes, and nucleated red blood cells in the blood smear. However, the total white blood cell count is lower than in chronic myeloid leukemia, red cell abnormalities are more pronounced, and teardrop-shaped red blood cells may be observed. Bone marrow biopsy often reveals significant fibrous tissue proliferation. Furthermore, chronic myeloid leukemia must also be differentiated from other conditions causing splenomegaly, such as cirrhosis, advanced schistosomiasis, and black Rebing.