Histochemical characterization of mucosubstances in bone and soft tissue tumors

Abstract

The present investigation endeavors to characterize the mucosubstance content of 170 myxoid and chondromatous tumors and chordomas by histochemical methods. The results obtained using the critical electrolyte concentration (CEC) method as introduced by Scott and co-workers23,24 were compared with those obtained by staining with alcian blue and toluidine blue at different pH's with and without pretreatment with bovine testicular hyaluronidase. Tissues known biochemically to contain different heteroglycans were used as controls: synovial fluid and cock's comb (hyaluronic acid) stained with alcian blue up to a MgCl2 concentration of 0.1 M; fetal cartilage (chondroitin 4- and 6-sulphate) pulposus with notochordal remnants (keratan sulphate) up 10 1.0 M. The staining reaction of intramuscular myxoma and myxoid liposarcoma corresponded to that of synovial fluid and cock's comb (containing hyaluronic acid). Benign chondromatous tumors (osteochondroma, enchondroma, extraskeletal chondroma, chondromatosis in bursae, synovia, and tendon) as well as well-differentiated chondrosarcomas had a similar staining reaction to that of adult cartilage (containing keratan sulphate). However, the intensity of the reaction was lower in these tumors than in the adult cartilage, indicating that the keratan sulphate content of the tumors is lower. Most of the moderately well-differentiated chondrosarcomas, the poorly differentiated chondrosarcomas, and pulmonary metastases of chondrosarcoma, as well as mesenchymal chondrosarcoma and extra-skeletal chondrosarcoma possessed the same staining properties as fetal cartilage, known to contain chondroitin 4- and 6-sulphate but not keratan sulphate. A few of the moderately well-differentiated chondrosarcomas stained up to a MgCl2 concentration of 1.0 M. Three cases of poorly differentiated chondrosarcomas stained with alcian blue up to 0.35-0.45 M in the lowest differentiated areas, indicating the presence of sulphated heteroglycans, as chondroitin 4- and 6-sulphate. Most chordomas possessed the same staining properties as fetal cartilage; however, a few chordomas stained in the same way as notochordal remnants of nucleus pulposus (containing keratan sulphate), which are thought to be the origin of these tumors. The results of staining of the tumors in the present series with the Scott technique corresponds well with toluidine blue and alcian blue at different pH's with and without pretreatment of the sections with testicular hyaluronidase. Since bone and soft tissue tumors may contain varying mucosubstances depending on the tissue of origin and on differentiation, histochemical investigation of the heteroglycan content of these tumors may be a valuable diagnostic aid.