Therapy associated changes in childhood tumors.

Contemporary treatment regimens for the common solid tumors of childhood have led to increased numbers of post-treatment pathologic specimens from survivors. Current therapeutic strategies for childhood cancers in North America require an accurate pathologic diagnosis and stratify patients based on combinations of clinical, biological, and pathologic features. In several tumor systems, the pathologic response to therapy also modifies the treatment regimen. Accurate pathologic interpretation of such specimens is critical in providing useful prognostic information for therapeutic decisions. Standardized handling of post-therapy pathologic specimens, appropriate use of molecular and genetic studies, consideration of the differential diagnoses, and assessment of the potential biologic significance of therapy-induced pathologic changes are, therefore, critical for patient management and determination of treatment protocols.