Radiologic and pathologic characteristics of benign and malignant lesions of the mandible.

Mandibular lesions develop from both odontogenic and nonodontogenic origins and have varying degrees of destructive potential. Common benign cystic lesions include periapical (radicular) cysts, follicular (dentigerous) cysts, and odontogenic keratocysts. Benign solid tumors represent a broad spectrum of lesions such as ameloblastomas, odontomas, ossifying fibromas, and periapical cemental dysplasia. Malignant tumors that often involve the mandible include squamous cell carcinomas, osteosarcomas, and metastatic tumors. In addition, vascular lesions such as hemangiomas and arteriovenous malformations may develop, further expanding the differential diagnosis. Because mandibular lesions have a wide range of pathologic features but similar imaging appearances, familiarity with embryologic characteristics and secondary findings is crucial. Patient age at manifestation, prevalence, location within the mandible, cystic or solid appearance, border contour, and effect of the lesion on adjacent structures are all considerations in making the diagnosis. Despite this information, however, many lesions are impossible to differentiate without biopsy. In such cases, defining the degree of malignant potential is very helpful. Although imaging will not always provide a specific diagnosis, it should help narrow the differential diagnosis, thereby helping to guide patient treatment. RSNA, 2006