Soft Tissue Tumors Rarely Presenting Primary in Bone; Diagnostic Pitfalls.

Primary bone sarcomas represent extremely rare entities. The use of now abolished labels, such as malignant fibrous histiocytoma and hemangiopericytoma, has significantly hampered the chance of identifying specific entities. It is now accepted that a broad variety of mesenchymal malignancies most often arising on the soft tissue may actually present as primary bone lesions. A more accurate morphologic partition is justified based on availability of distinct therapeutic options. An integrated diagnostic approach represents the only way to achieve a correct classification. In consideration of the significant complexity, primary bone sarcomas should ideally be handled in the context of expert centers.