What is the most common type of leukemia in children?

The most common type of leukemia in children is Acute Lymphocytic Leukemia (ALL). This type accounts for approximately 25% of all childhood cancers and occurs most frequently in children between one and four years of age [2]. In this condition, the bone marrow produces excessive amounts of immature white blood cells (lymphocytes), which accumulate in the blood and bone marrow, crowding out healthy blood cells and making it difficult for the body to perform its vital functions [1].

Other types of childhood leukemia

Although Acute Lymphocytic Leukemia is common, other types may affect children, though they are less frequent:

• Acute Myeloid Leukemia (AML): Occurs when the bone marrow produces abnormal myeloid cells; it is classified as an acute cancer that requires rapid intervention [1] [3].
• Chronic leukemia: Such as Chronic Myeloid Leukemia (CML), which is very rare in children. In this condition, the situation worsens more slowly than in acute types [1] [3].
• Rare types: Including Juvenile Myelomonocytic Leukemia (JMML), another rare condition that may appear in early childhood [3].

Symptoms that warrant parental attention

Most symptoms of leukemia arise from a deficiency in healthy cells (such as oxygen deficiency due to low red blood cell counts, or bleeding due to low platelet counts) or from the accumulation of cancer cells. You should consult a doctor if you notice signs such as: [2]

• Increasing skin paleness, persistent weakness, or unexplained fatigue.
• Recurrent fever or night sweats without an obvious infection.
• Easy bruising or abnormal bleeding, or the appearance of tiny red spots under the skin (petechiae).
• Bone or joint pain, or enlarged, painless lumps in the lymph nodes (neck, armpit, groin) [2] [3].
• Unexplained loss of appetite or weight loss.

These symptoms may result from other medical conditions, but a doctor is the only one capable of accurately determining the cause through laboratory tests [2].

Diagnosis and medical care

Diagnosis usually begins with a comprehensive physical examination and detailed medical history, followed by a Complete Blood Count (CBC) to evaluate blood cell levels [2]. If a doctor suspects leukemia, a bone marrow examination (biopsy) and genetic tests may be required to understand the type of cancer cells and develop a personalized treatment plan [1] [3]. Treatment may include multiple stages of chemotherapy, and sometimes radiation, based on the child's individual case [2]. For more details on the medical pathway, you can review our article on Childhood Leukemia: Early Symptoms, Diagnosis, and Treatment (Arabic).

Note: Leukemia requires urgent medical evaluation. If your child is experiencing difficulty breathing, severe bleeding, or sudden changes in consciousness, you should go immediately to the nearest emergency department.

Medical references

• Childhood Leukemia
• Childhood Acute Lymphoblastic Leukemia (PDQ®)–Patient Version
• Childhood Acute Myeloid Leukemia/Other Myeloid Malignancies Treatment (PDQ®)–Patient Version