From the archives of the AFIP. Primary tumors of the spine: radiologic pathologic correlation.

Primary tumors of the spine are relatively infrequent lesions compared with metastatic disease, multiple myeloma, and lymphoma. However, when a solitary lesion of the spine occurs, these neoplasms represent an important group of entities for diagnostic consideration. A wide variety of benign neoplasms can involve the spine, including osteoid osteoma, osteoblastoma, aneurysmal bone cyst, giant cell tumor, enostosis, and osteochondroma. Common primary nonlymphoproliferative malignant neoplasms of the spine include chordoma, chondrosarcoma, Ewing sarcoma or primitive neuroectodermal tumor, and osteosarcoma. The imaging features of these lesions of the spine are often characteristic. These changes include a small sclerotic focus with irregular thorny margins in the vertebral body (enostosis), a small radiolucent nidus with central calcification in the posterior elements of the vertebral body (osteoid osteoma), a large expansile lesion with multiple fluid-fluid levels (aneurysmal bone cyst), and an aggressive mineralized mass (chondroid or osteoid) with osseous and soft-tissue involvement (chondrosarcoma or osteosarcoma). Radiologists should be aware of the appearance of these unusual neoplasms in order to provide a complete differential diagnosis and to guide clinical colleagues in patient treatment.