Abstract
A case of peripheral ameloblastoma with massive bone resorption was reported. A 73-year-old woman presented with a swelling on the edentulous alveolus in the left premolar region of the lower jaw. It was a 20 × 15 mm, elastic hard mass with a smooth and reddish surface. An X-ray examination showed massive resorption of the underlying jaw bone. A tissue biopsy revealed the lesion was peripheral ameloblastoma. The tumor was excised. Because the tumor had a fibrous capsule, it was easily removed from the jaw bone. Thus only the superficial part of the bone was removed with a dental round bar. Histologically, the excised tumor was follicular and acanthomatous ameloblastoma largely surrounded by fibrous connective tissue. It was directly contiguous with the gingival epithelium. Peanut agglutinin reactivity and cytokeratin 19 immunoreactivity indicated the tumor was not central ameloblastoma or basal cell carcinoma, respectively. The tumor cells showed a Ki-67 labeling index (13.7%) similar to the previously-reported central-ameloblastoma cells, suggesting that the aggressive nature of the tumor led to the massive bone resorption. As of 2 years postoperatively, there is no evidence of recurrence and the patient's progress is good.
