[Differential diagnosis of intramedullary osteosarcomas].

Intramedullary high-grade osteosarcomas are aggressive tumors with a high metastatic capacity. The many subtypes and variants of these tumors often make the differential diagnosis difficult. Therefore, a critical review of both radiology and histomorphology is mandatory. Low-grade central osteosarcomas are a completely different tumor group. Due to their strong similarity to benign bone tumors they are frequently misdiagnosed as such. The correct diagnosis followed by radical surgery, however, is essential to reduce the high risk of local recurrences, typically seen for of these lesions. Unlike conventional high grade osteosarcomas, distant metastases are much less frequent than in low grade osteosarcomas.