Approach to Primary Vertebral Tumors in the Light of the 2020 Updated World Health Organization Classification of Bone Tumors.

Abstract

To define a new approach for primary vertebral tumors by discussing them in the light of 2020 World Health Organization (WHO) classification of bone tumors. In this study, we have discussed primary vertebral tumors in light of the 2020 Updated WHO Classification of Soft Tissue and Bone Tumors. Chondroblastoma and chondromyxoid fibroma has been classified in the benign category, while synovial chondromatosis has been moved from the benign category to the intermediate category. In the updated classification, grade I chondrosarcoma has been classified in the malignant category with grade II?III chondrosarcomas. Minor amendments have been made for osteosarcoma subtypes. Neoplasms of undetermined origin, such as aneurysmal cysts, simple bone cysts, fibrosis dysplasia, and osteofibrous dysplasia, have been classified as neoplastic lesions. Chordomas have been classified into ?not otherwise stated,? poorly differentiated chordomas, and dedifferentiated chordomas. Ewing?s sarcomas have been classified in a separate section for undifferentiated, small, round cell sarcomas of the bone and soft tissue. In this section, three distinct subsets different from Ewing?s sarcoma have been discussed. CIC-rearranged sarcoma, BCOR-rearranged sarcoma, and round cell sarcomas with EWSR1 gene fusion with non-ETS family members. In this study, we have reviewed the new classifications and discussed their effect on decision making in spinal oncologic surgery.