Which of the following leukemia is the most common in pediatric age group?

الشرح

Core Concept: Acute Lymphoblastic Leukemia (ALL) is a malignant proliferation of immature lymphoid blasts in the bone marrow and is the most common childhood cancer, accounting for about 75-80% of all pediatric leukemias. Peak incidence is between 2 and 5 years of age.

Clinical Presentation: Symptoms of bone marrow failure (pallor/anemia, fever/infections, bleeding/petechiae/thrombocytopenia), bone pain, lymphadenopathy, and hepatosplenomegaly.

Diagnosis: First-line is a complete blood count (CBC) showing abnormal WBC counts, anemia, and thrombocytopenia, with circulating blasts. Gold standard for definitive diagnosis and classification is a bone marrow aspiration and biopsy showing >20% lymphoblasts, followed by flow cytometry (immunophenotyping), cytogenetics, and molecular testing.

Management: Acute management involves stabilization, tumor lysis syndrome prophylaxis (hydration, allopurinol/rasburicase), and transfusions. Long-term definitive management consists of multi-agent systemic chemotherapy divided into induction, consolidation, and maintenance phases over 2-3 years. CNS prophylaxis (intrathecal chemotherapy) is mandatory. High-risk or relapsed cases may require hematopoietic stem cell transplantation.