線維性異形成から発生した下顎軟骨肉腫の稀な症例

Fibrous dysplasia is an uncommon, intramedullary fibro-osseous lesion representing approximately 5% to 7% of benign fibro-osseous lesions. The incidence of malignant transformation of fibrous dysplasia is considered very rare. The aim of this case report is to present a rare case of a chondro-sarcomatous transformation of a case previously diagnosed with mandibular fibrous dysplasia, a patient who was initially referred for a gingival tumoral extirpation in the third quadrant. A 57-year-old female patient presented for a consultation and, after a biopsy, was diagnosed with fibrous dysplasia of the mandibular bone. After two interventions of surgical removal of the lesion, the malignant transformation of chondrosarcoma occurred, which was identified by radiologic and histopathologic investigations, with the overall AJCC staging being pT1N0M0, G3. Radical resection of the mandibular bone with free margins of tumor was performed. Malignant transformation of mandibular fibrous dysplasia is a very rare and challenging complication of this disease. Early recognition and proper surgical treatment must be the key actions from doctors and clinicians.