Cytologic and cytochemical behavior of primary malignant bone tumors.

Cytologic and cytochemical examination of eighteen cases of round-cell sarcoma of bone allowed classification of these tumors into four cytologic groups. Additional cytochemical examinations based on the PAS and D-PAS reactions, and the demonstration of the activity of peroxidase, naphtol-ASD-Chloracetate esterase, alpha-naphthylacetate esterase, naphthol-AS-acetate esterase with and without sodium fluoride inhibition, acid and alkaline phosphatases yielded no evidence of uniform behavior among the individual groups or within any single group. The studies showed that a positive glycogen reaction cannot be used as a basic criterion for the classification of such tumors as Ewing's sarcoma and for regarding them as a uniform tumor group. It is possible that a pool of tumors is involved, including tumors of monocytic and probably of lymphocytic origin, reticulum-cell sarcoma, tumors of myelocytic and erythroplastic origin, stem-cell tumors, and endothelial-cell tumors. Histologic examination alone is not sufficient for the classification of round-cell sarcomas of bone, and it should be supplemented by cytologic and cytochemical or histochemical methods. Osteosarcomas (23 cases) and chondrosarcomas (8 cases) display cells which are characteristic for these tumors and which could be correlated with their benign counterparts, osteoblasts and chondroid cells. The histologically recognizable degree of malignancy of chondrosarcoma can be evaluated better with the cytologic than with the histologic technic. Indications of the possibilities of differential diagnosis based on the cytologic pictures of benign and malignant osteoplastic and chondroplastic tumors, giant-cell tumors and chordoma are discussed.