Central ossifying fibroma: A clinicopathologic study of 28 cases

Background/purpose: Central ossifying fibroma (COF) is the most common benign fibro-osseous lesion of the jaw. This retrospective study evaluated the clinical and histopathologic features of 28 COFs in Taiwanese patients. Methods: Twenty-eight consecutive cases of COF were collected from 1988 to 2006. The clinical data and microscopic features of these cases were reviewed and analyzed. Results: The mean age of patients at the time of diagnosis was 34 years. There were six male and 22 female patients. Twenty-six (93%) cases were found in the mandible and two (7%) in the maxilla. The most common sites for COFs were the molar region (17 cases, 61%), followed by the premolar (8 cases, 28%), and incisor/canine (3 cases, 11%) regions. Bone swelling or expansion (96%, 26/27) was the most frequent clinical presentation. Six (21%) COFs presented as a radiolucent lesion, 17 (61%) as a mixed lesion, and five (18%) as a radio-opaque lesion. No recurrence of the lesion was found after surgical excision in this series. Microscopically, COFs showed trabeculae of woven bone (25 cases) and/or lamellar bone (5 cases) and/or spherules of cementoid (19 cases) in a cellular fibrous connective tissue stroma. The stromal component was highly cellular in 21 cases, moderately cellular in seven cases, prominently vascular in 11, and collagenous in six. Conclusion: COFs occur more frequently in female patients and in those in the second to fourth decades of life. The most commonly affected site is the mandible, especially the molar region. The majority of COF lesions present as a well-defined, mixed lesion radiographically. Most COFs can be treated by conservative surgical excision without subsequent recurrence. ? 2008 Elsevier & Formosan Medical Association.