Peculiar features and tailored management of adult cancers occurring in pediatric age.

Most of the tumors typical of adult age, that is, gastrointestinal cancers, melanoma, lung and breast cancers, and carcinomas of the head and neck, may also occur - albeit very rarely - in children, and pediatric oncologists have defined them as 'rare (or very rare) pediatric tumors'. Given the scarce data available in the literature, the clinical management of children with these tumor types is a real challenge for pediatric oncologists and surgeons. Adult tumors often differ in many aspects from the malignancies typical of pediatric age, and the diagnostic and treatment guidelines adopted for children when they develop 'adult' cancers are generally extrapolated from those applied to adults. However, the biology and clinical course of some adult tumors seem to change when they occur in children, thus suggesting the need for tailored approaches. This article describes a few such tumors and points to the need for forms of international cooperation with a view to gaining a better understanding of these particular conditions and improving patient management.