What is the most common pediatric malignancy?

Leukemia, particularly acute lymphoblastic leukemia (ALL), is recognized as the most common pediatric malignancy. It typically presents in children between the ages of 2 and 5 and comprises about one-third of all pediatric cancers. The pathophysiology involves the uncontrolled proliferation of lymphoid progenitor cells in the bone marrow, which leads to various clinical manifestations such as anemia, bruising, frequent infections, and lymphadenopathy.

Neuroblastoma, Wilms tumor, and retinoblastoma, while significant in the pediatric oncology landscape, are less prevalent than leukemia. Neuroblastoma primarily affects very young children and is a cancer of the sympathetic nervous system. Wilms tumor is a kidney cancer that predominantly affects children aged 3 to 4 years. Retinoblastoma is a cancer of the retina that typically presents in children under 2 years old. Each of these malignancies has distinct characteristics, treatment protocols, and outcomes, but they do not outnumber the incidence of leukemia in the pediatric population. This context helps clarify why leukemia, especially ALL, is classified as the most common malignancy in children.