A central odontogenic fibroma mimicking a dentigerous cyst associated with an impacted mandibular third molar—Immunohistological study and review of literature

Abstract

Odontogenic fibroma is a relatively rare and benign odontogenic tumor of mesodermal dental sac or periodontal ligament origin. We report a case of central odontogenic fibroma (COF) mimicking a dentigerous cyst associated with an impacted left mandibular third molar, together with immunohistological studies and a literature review. Including present case, a total of 24 cases of COF have been investigated immunohistologically to determine the origin of epithelial components or fibroblasts found in the parenchyma of the tumors. In the present case, the epithelial components were strongly positive for cytokeratin (CK AE1/AE3), and the fibroblasts were positive for vimentin. The site around the hard tissue was strongly stained by vimentin. Surgical findings indicated that the tumor extended to the periodontal ligament, suggesting that the tumor possibly originated in the periodontal ligament. A review of the literature revealed that COF occurs in the fourth to fifth decade, exhibits no sex difference, and has a good prognosis after surgery. Radiographic images of COF occasionally mimic dentigerous cysts, but there are no particular radiographic features distinguishing COF. Diagnosis is usually based on histological findings. Immunohistological studies may also be useful in the diagnosis of COF.