[Histological and immunohistochemical studies in cases of malignant mesenchymal neoplasms of the oromaxillofacial area].

The authors present an immunohistochemical study of 11 cases of maxillo-facial primitive sarcomas. Specimens from demoliti maxillary resections were prepared and stained with alpha-1-antichymotrypsin, lysozyme and CD68. Alpha-1-antichymotrypsin confirmed in this study its lack of specificity as a tumor marker being relevated both in fibroblasts and in osteoblasts and even in chondrosarcomatous tissue. The results of lysozyme and CD68 stainings were interesting especially in malignant fibrous histiocytoma (MFH), fibrosarcoma and osteosarcoma. The authors showed, once more, that while in osteosarcoma the markers were noted in osteoclasts or pre-osteoclasts alone and not in the neoplastic stroma; all fibroblastic elements were marked in MFH. Immunohistochemical research of histiocyte-macrophage lineage confirmed its utility in osteosarcoma versus MFH differential diagnosis. In fibrosarcoma, furthermore, the authors obtained a positive staining of CD68 and lysozyme in fibroblastic elements morphologically similar to the other neoplastic cells. This datum induced the authors to formulate the interesting hypothesis that MFH and fibrosarcoma represent the opposite ends of a wide spectrum of differentiation of a single neoplasm of fibrohistiocytic origin.