Table 2.

Histological grading in bone sarcomas

Grade I

Parosteal osteosarcoma

Low-grade intramedullary osteosarcoma

Atypical cartilaginous tumor/ grade I chondrosarcoma

Clear cell chondrosarcoma

Grade II

Periosteal osteosarcoma

Grade II chondrosarcoma

Classic adamantinoma

Chordoma

Grade III

Osteosarcoma (conventional, telangiectatic, small cell, secondary, high-grade surface)

Undifferentiated high-grade pleomorphic sarcoma

Ewing sarcoma

Grade III chondrosarcoma

Dedifferentiated chondrosarcoma

Mesenchymal chondrosarcoma

Dedifferentiated chordoma

Malignancy in giant cell tumor of bone