Topography of childhood tumors: pediatric coding system.

The importance of a uniform coding system for cancer research, tumor registry, and exchange of information is recognized. However, tumors arising in children differ from those in adults, resulting in lack of precision when one coding system is used for both. Because the topographic code of the International Classification of Disease for Oncology for adult tumors does not lend itself well to pediatric tumors, the International Society of Paediatric Oncology (SIOP) developed a four-digit topographic coding system particularly adapted to childhood tumors. The four digits correspond to anatomic site, general and specific localization, and tissue of origin. An SIOP pilot study demonstrated the usefulness of this code.