Chondrosarcoma, Grade I
Low-grade chondrosarcomas may be extremely difficult to differentiate from chondroma confidently on histopathologic features alone. Interpretation should always be done in the context of the location of the tumor and the radiographic findings. This image shows a Grade I chondrosarcoma permeating and entrapping the bony trabeculae. Permeation of adjacent bone is an important distinguishing feature from enchondromas which tend to form well-circumscribed nodules.