Abstract

Ameloblastic fibrosarcoma is an extremely rare variety of odontogenic tumor. It has not previously been reported in Korea. The tumor is composed of benign odontogenic epithelium with a mesenchymal part which exhibits the histologic features of fibrosarcoma. We have reported a case of amloblastic fibrosarcoma of the mandible in a 26-year-old man with swelling of right mandible for 2 weeks. The tumor showed yellowish ill-demarcated ulcerating mass involving right premolar and molar area. Light microscopy revealed irregularly arranged strands and islands of odontogenic epithelium surrounded by abundant mesenchymal tissue with the feature of fibrosarcoma. The fibrosarcoma cells were strong positive on immunostain for vimentin and ameloblastic cells were weakly positive for cytokeratin. S-100 and CEA were negative in both epithelial and sarcoma cells. The sarcoma cells were corresponding to fibroblasts on the electron microscopy with abundancy of RER and mitochondria and covering of basal lamina. Two types of virus like particles were distributed in the cytoplasm and nuclei of sarcoma cells. We treated the patient with surgery and chemotherapy. The recovery was uneventful and the prognosis is under observation.

• Keywords: Ameloblastic fibrosarcoma;Virus-like particles