[Mesenchymal chondrosarcoma--report of 4 cases].

This paper reports 4 cases of mesenchymal chondrosarcoma, 1 case in the retroperitoneum, 1 the left mandible, 1 right thoracic wall and 1 right thigh. 2 males and 2 females. The age ranged from 18 to 42 with an average of 29 years. In this series, 3 patients are still alive after operation and one died one year postoperatively. Microscopic examination: the tumor was made up not only of undifferentiated mesenchymal cells, but also of well-differentiated cartilaginous islands and hemangiopericytomalike lesions. Transitions between the undifferentiated small cells and neighbouring chondrocytes or chondroid matrix and collagenous fibers can be found microscopically in all cases. The authors emphasize that collagenous fibers between the undifferentiated cells play an important role in the formation of cartilaginous islands. The differential diagnosis of this disease is discussed.