Osteochondroma is the most common benign bone tumor. Approximately 15% of osteochondromas occur as multiple lesions. Multiple osteochondromatosis has a higher risk of developing chondrosarcomas, which are of low grade with good prognosis. About 10% of all chondrosarcomas may undergo dedifferentiated change, which has a poorer prognosis. Dedifferentiated peripheral chondrosarcoma developing with...

Note Dedifferentiated chondrosarcoma was first proposed in 1971 by Dahlin and Beabout. It is characterized by two distinct histopathological components; a well-differentiated benign chondral lesion or chondrosarcoma (any grade) sharply juxtaposed with a high-grade non-cartilaginous component; typically there is an abrupt transition between the two tissue types. The non-cartilaginous component o...

Seven years ago, a 48-year-old female patient discovered a painless tumor in her right breast simply by chance. In the next year, the tumor increased significantly in size. At this point, the patient received a tumor resection, which was misdiagnosed as a benign mesenchymal tissue-originated tumor. Unfortunately, the tumor recurred just 10 days after resection. We subsequently resected the recu...