S-100 protein in tumors of cartilage and bone. An immunohistochemical study.

Using the peroxidase-antiperoxidase (PAP) immunohistochemical method, S-100 protein was found in well-differentiated chondrocytes of chondroma, chondroblastoma, mesenchymal chondrosarcoma, and osteosarcoma. It was not detected in osteoma, osteoblastoma, giant cell tumor, and Ewing's tumor. The presence of S-100 protein in tumorous chondrocytes and chondroblasts suggests that this protein may be a marker of chondrocyte origin and should not be considered a specific marker for nerve tissue.