Pediatric tumors

Some pulmonary lesions of an overtly neoplastic or quasi-neoplastic nature present in the first two decades of life proportionately less frequently than in adults. However, the major category of malignant tumors involving the lung in both children and adults is similar; that category is metastatic disease, which in adults is usually a carcinoma or melanoma and in children is rhabdomyosarcoma, osteosarcoma, Ewing sarcoma-primitive neuroectodermal tumor, germ cell neoplasms, and Wilms' tumor. Unusual sources of metastatic disease to the lungs in children include chordoma, epithelioid hemangioendothelioma, malignant fibrous histiocytoma, and neuroblastoma. The lungs are also important sites for the quasi-neoplastic processes, Langerhans cell histiocytosis (histiocytosis X), and juvenile xanthogranuloma as infiltrates or reticulonodular densities.