Ossifying fibroma misdiagnosed as chronic apical periodontitis.

INTRODUCTION: Ossifying fibroma mimicking chronic apical periodontitis is extremely rare. This report describes a case of ossifying fibroma located in the periapical region of the mandibular right canine that was misdiagnosed as chronic apical periodontitis. METHODS: A 40-year-old woman complained of slight pain in the right anterior mandibular region without mucosal abnormalities or swelling. Radiographically, a well-circumscribed, unilocular, radiolucent lesion was observed that was located in the periapical region of the mandibular right canine, which presented an endodontically treated root canal. Under local anesthesia, the lesion was fully excised. RESULTS: Microscopically, there was fibrocellular connective tissue associated with a mineralized component, which consisted of lamellar or trabecular and woven bone, compatible with the diagnosis of ossifying fibroma. CONCLUSIONS: Although it is very rare, ossifying fibroma should be considered in the differential diagnosis of unusual or persistent apical radiolucencies.