| Namespace | disease_ontology | Obsolete | false |
| description | A bone osteosarcoma that is characterized by the presence of osteoid extracellular matrix and that arises from the medullary portion of the bone. It affects the long bones and most commonly, the distal femur, proximal tibia, and proximal humerus. Pain with or without a palpable mass is the most common clinical presentation. |
