To study the clinical pathological characteristics and differentiation diagnosis of the chondroid parachordoma from primary tumors or metastatic to ulna, femur and radius. Methods Three cases of primary chondroid parachordoma of the ulma, femur and radius were studied by histopathological observation and immunohisto chemical staining and by pathological consultation. Results The histological features of tumor were composed of two the chordoma ceils subtotal and the chondrosareoma ceils of small - portio. The tumor was arranged vary in sizes of lobular and brink of lobular were seplum small girder of chondroid, or the tissue fiber. The tumor cells were distributed sheet, trabecula with or island -like in the intralobular, and the tumor ceils were vary in size and the karyon heterotypic were no patent and the cytoplasm of rich shows large vacuole. The chondroidosarcomas intra - lobular were viewed ceils both nucleus and uninuclear of chondrolacunae and the stroma were hyaling cartilage with or blennoid in the mesenchyma, and that picture of typical chondrosarcoma. EMA, CK, Vimentin, S - 100 protein, NSE with immunohistochemical method (ABC) staining were positive and Desmin, CD34 negative in the all of tumor cells. The chondroid parachodoma was diagnosed in the pathological read- section- conference and consulation. Conclusion Primary ulna, femur and radius chondroid parachordoma is a rare in rate of neoplasm and is diagnosed diflqculdy. Immunohistochemical method would be helpful to diagnosis.
