Rare pediatric non-hodgkin lymphoma.

Of the cases of non-Hodgkin lymphoma (NHL) diagnosed in children and adolescents, 10% comprise a diverse mixture of unusual B-cell or T-cell disease, some types of which are more commonly seen in adults. Understanding of these rare types of NHL comes from small pediatric case series or the adult literature. Some rare pediatric NHL is similar to adult NHL, but other types have different molecular and cytogenetic characteristics. It is important to improve understanding and treatment of these rare pediatric NHLs through international collaborative efforts.