The most common malignant neoplasm of infancy is

Neuroblastoma is the most common extracranial and intra- abdominal solid malignant tumor of infancy.It is a disease of early childhood with approximately 90% of patients presenting before 5 years of age & almost 50% within the first 2 years of life. Reference:Essential pediatrics-Ghai,8th edition,page no:616.