Malignant Lymphomas in Childhood

Malignant lymphomas are the third most common malignancy among children and adolescents. Among children less than 15 years of age, non-Hodgkin lymphoma (NHL) is more frequent; however, in patients up to 18 years of age, Hodgkin lymphoma (HL) is predominant. NHLs in children are usually extranodal diffuse high-grade tumors, whereas low- and intermediate-grade nodal lymphomas predominate in adults. These differences are speculated to reflect maturational changes in the function and composition of the immune system. The different histologies explain in part the differing clinical features, disease course, and treatment strategies used in adults and children. The differences in treatment approach and disease subtypes are less striking in adults and children with HL. However, there are significant challenges in the management of children with HL. These primarily comprise the sequelae of therapy, such as radiation-induced bone growth abnormalities, endocrine dysfunction, and chemotherapy-related sterility. Of greater concern are the radiation- and chemotherapy-related second malignancies and late cardiac deaths. Current trials are examining ways to reduce the toxicity of therapy without compromising the excellent outcome generally achieved.