Classification schemes for tumors diagnosed in adolescents and young adults

The International Classification of Diseases for Oncology (ICD‐O) is a collaborative undertaking of the International Agency for Research on Cancer and the National Cancer Institute in the U.S., under the aegis of the World Health Organization. Although the ICD‐O system generally is applicable to cancer diagnosed in childhood, it is recognized that morphology takes precedence over topography in classifying neoplasms occurring in children. Consequently, a classification scheme has been proposed that although based on the ICD‐O is tailored to the particular circumstances of adolescents and young adults with cancer.