Osteoblastoma of the mandible: clinicopathologic study of four cases and literature review

Background. Osteoblastoma is a benign bone tumor accounting for 1% of all bone tumors; it commonly involves the spine and the sacrum of young individuals, with less than 5% being localized to the posterior mandible. In view of its rarity in the maxilla and mandible, osteoblastoma is rarely diagnosed as such in the absence of interdisciplinary cooperation. Methods. A retrospective study of four benign osteoblastomas was performed based on a review of the clinical, radiographic, and histopathologic features of all cases. Results. The tumors involved the posterior mandible of young patients (age range, 10-21 years; two male and two female patients) and appeared as painful bone expansions. Radiologically, they were poorly defined, radiolucent/radiopaque lesions containing calcifications and not showing sclerotic borders or periosteal reactions. Histologically, they were composed of osteoid and woven bone surrounded by plump osteoblast-like cells with interposed fibroblasts, inflammatory cells, and red blood cells. All patients were disease free after prolonged follow-up. Conclusions. Osteoblastomas may be distinguished from other bone tumors, fibro-osseous lesions, and odontogenic neoplasms on the basis of integrated clinical, radiologic, and histo-logic features and usually manifest an indolent clinical course