NCIt related terms : Central osteosarcoma; Central; Medullary osteosarcoma;
NCIt definition : A high grade malignant bone-forming mesenchymal neoplasm producing osteoid. The tumor
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. It usually has an aggressive
growth and may metastasize through the hematogenous route. The lung is the most frequent
site of metastasis.;