Bone Neoplasms: Osteosarcoma and Ewing Sarcoma

Malignant primary bone tumors in children are most often osteosarcoma or Ewing sarcoma. These two entities make up approximately 90% of all pediatric bone malignancies, with chondrosarcoma being infrequent in children. Osteosarcoma (OS) is classified as a malignant neoplasm with osteoid production. Ewing sarcoma (ES) is thought of as a peripheral primitive neuroectodermal tumor and demonstrates classic features of small-blue-round-cell tumors. Initial diagnostic evaluation of any pediatric bone lesion should begin with radiography with local staging of suspicious lesions best accomplished by MRI. The combination of chest CT and FDG-PET/CT are commonly used to ascertain metastatic involvement. Imaging plays a vital role in post-treatment follow-up with evidence-based approaches outlined in this chapter.