Fibro-osseous lesions of the craniofacial bones are a challenging group of pathologicconditions that are difficult to classify. Unfortunately, there are no universally accepted clinical, radiographic, or histopathologic criteria that categorically distinguish these lesions from one another. A case ofbenign oseoblastoma of the right side of the mandible with diverse histopathologic findings is reported. Thepatient was a 9-year-old Spanish-Peruvian girl who presented with enlargement of the right side of themandible of 4 months' duration. Mandibular radiographs showed a well circumscribed mass containing both radiopaque and radiolucent lesions without periosteal spiculated new bone formation. Extirpation and curretage of the lesion were done. Histologically, the tumor was composed of lesions cosistent withbenign osteoblastoma. The peripheral region of the tumor mimicked fibrous dysplasia, cemento-ossifying fibroma, and sclerosing osteomyelitis. The final diagnosis was mandibular benign osteoblastoma. One year 8 months postoperatively, the patient was well, with no sign of recurrence.
