Primary malignant tumors of bone surface:a review with emphasis in differential diagnosis

Surface tumors of the bone are broadly defined as a diverse group of osteogenic and chondrogenic benign and malignant neoplasms that arise adjacent to the outer surface of cortical bone.They may be a cause of diagnostic difficulty due to a degree of histological overlap,rarity,and nomenclature.In this review we summarize the different histological types of primary malignant tumors of bone surface,namely,secondary peripheral chondrosarcoma,periosteal chondrosarcoma,parosteal osteosarcoma,dedifferentiated parosteal osteosarcoma,periosteal osteosarcoma,and high-grade surface osteosarcoma.We provide a comprehensive updated review of their pathogenesis and highlight radiological,macroscopic,and histopathological features and recently available ancillary diagnostic tools that may aid in the differential diagnosis.