A case of peripheral odontogenic fibroma in the maxillary molar region

A case of peripheral odontogenic fibroma occurring in the posterior region of the maxilla in a 7-year-old girl is presented. The patient was referred to our hospital because of a painless swelling in the buccal gingiva at 6 1. Physical examination revealed a localized elastic-hard tumor, with no radiological abnormalities in the adjacent alveolar bone. A biopsy specimen showed proliferation of fibroblastic cells in the submucosal layer. With the patient under general anesthesia, the tumor was resected subperiosteally, and the underlying bone surface was smoothened with a bur. Histologically, the lesion was composed of cellular fibrous connective tissue with scattered regions of cellular strands interwoven with less cellular areas and islands of odontogenic epithelium. The final diagnosis was peripheral odontogenic fibroma. Specific staining demonstrated that the tumor stroma contained large amounts of oxytalan fibers and tenascin. A positive reaction for tenascin was found to be a valuable pathohistological marker that could distinguish between peripheral odontogenic fibroma and calcifying fibrous epulis.As of about 9 years after the operation, there has been no evidence of recurrence.