An ultrastructural study of malignant fibrous histiocytoma of the larynx

Abstract

Abstract. Malignant fibrous histiocytoma (MFH) of the vocal cord occurring in a 46-year-old male was studied immunohistochemically and ultrastructurally. The tumor consisted of the two main areas, pleomorphic and storiform, lmmunohistochemical staining was strongly positive for al-antitrypsin and al-antichymotrypsin, and negative for desmin, keratin, myoglobin, actin, carcinoembryonic antigen, and S100 protein. Ultrastructurally, this MFH consisted of four different types of cells which were either fibroblast-like, histiocyte-like, myofibroblast-like, or with features of both the fibroblast and histiocyte types. Transition forms between the four types of cells were also found. This suggests that cells of MFH are derived from the same undifferentiated stem cells.