Fibrosarcoma originating in the mandible

Fibrosarcoma is a malignant mesenchymal neoplasm of fibroblasts that rarely affects the oral cavity and can cause local recurrences or metastasis. In this article we describe a case of primary fibrosarcoma in the mandible in a 16-year-old girl. Microscopically the tumor showed an intense proliferation of spindle-shaped cells, varying little in size and shape and arranged in parallel bands, partly crossing each other, the mitotic activity was increased and there was nuclear pleomorphism. Immunohistochemically the cells only showed immunoreactivity for vimentin and negativity for S-100 protein, CD 68, cytokeratin cocktail, HMB-45, CD34, pan actin HHF 35, desmin, smooth muscle actin and epithe…