Pathology of the breast in children, adolescents, and young adults.

The pathologic spectrum of breast disease in children and adolescents is broad and includes entities more commonly seen in older patients. In general, the vast majority of breast masses in young patients are benign with fibroadenomas, gynecomastia, and macromastia accounting for the majority of surgical specimens. Malignant tumors are more likely to be secondary or metastatic than primary. Rhabdomyosarcoma and hematolymphoid tumors comprise a majority of malignant diagnoses in children. Primary carcinomas and sarcomas are rare, especially if sarcomas arising in the setting of cystosarcoma phyllodes are excluded.