Osteosarcoma: Classification

Based on their histologic (fine tissue) characteristics, the WHO (World Health Organization) classifies osteosarcomas as follows:

Classification Subtype
Primary osteosarcoma
Central (medullary) osteosarcoma
Classic osteosarcoma

  • Chondroblastic
  • Fibroblastic
  • Osteoblastic
Teleangiectatic osteosarcoma
Intraosseous well-differentiated osteosarcoma (low-grade)
Small cell (mesenchymal) osteosarcoma
Superficial (peripheral) osteosarcoma
Parosseous (juxtacortical) well-differentiated osteosarcomas.
Periosteal osteosarcomas, well to moderately differentiated
High-grade osteosarcoma (conventional osteosarcoma) (poorly differentiated)
Secondary osteosarcoma

Lodwick classification

By means of the Lodwick classification, it is possible to assess whether the tumor is benign (benign) or malignant (malignant) on an X-ray. Furthermore, it is suitable for the assessment of progression in the case of aggressive behavior of the tumor.

An index for the growth rate of the bone tumor or an inflammatory process is the reaction visible on the X-ray, i.e. the bone structure is modified locally, regionally or diffusely by the tumor. The visible patterns of destruction are classified into the following main groups:

Grade Growth rate Bone destruction Dignity* Bone tumors
Grade I Purely geographic (circumscribed); boundary definable
  • A
Very slow growing Sclerosis (pathological hardening of here: tissues) and sharp boundary benign Chondroblastoma, enchondroma, fibrous bone dysplasia, nonossifying fibroma, osteoid osteoma
  • B
Slow growing (displacing) Bone distention > 1 cm and/or no sclerosis actively benign Giant cell tumor
  • C
Mean growth rate(locally invasive) Total compact penetration (compacta = outer marginal layer of bone). aggressive benign Chondro-, osteo-, fibrosarcomas
Grade II fast growing Geographic, with moth-eaten/permeated (without respect for anatomical boundaries) component predominantly malignant Chondrosarcoma, fibrosarcoma, malignant fibrous histiocytoma, metastases, osteosarcoma
Grade III very fast growing purely moth-eaten or permeative destruction malignant Ewing’s sarcoma

* biological behavior of tumors; i.e., whether they are benign (benign) or malignant (malignant)The classification is particularly suitable for tumors of a long bone or small bone. However, it is neither sensitive nor specific, so further diagnostic measures are usually indispensable.