Abstract
A 65 year old man first noticed painless gingival swelling in his anterior mandibular region approximately one year before. Later the swelling gradually increased in size.
Oral examination revealed a 30×25mm gingival lesion on the labial and lingual alveolus, that was located in the region from the right lateral incisor to the left first premolar and its surface was smooth and not ulcerated. The lesion was not tender and hard like bone in consistency. There were no signs of inflammation and the contiguous teeth were neither mobile nor tender on percussin.
The panoramic radiograph showed a large, circumscribed, radiolucency and the margin was irregular. It was located in the area between right lateral incisor and left first premolar, where numerous, irregular-shaped bone trabeculare were scattered and it produced a soap bubble or a honey-comb appearance that was uncommon radiographic findings of ameloblastoma of the mandible. The roots of left lateral incisor and canine teeth were inclined and estranged by the expanding tumor, but the resorption of root was not observed. The tumor was excised with the marginal resection of the mandible.
Microscopic examination disclosed nests and islands of stratified squamatous epithelium in fibrous stroma. The surface of the islands showed a palisading arrangement of columnar or cuboid cells. In some areas, there were polyhedral cells resembling the stellate reticulum and cystic spaces in the center of islands which appeared to be odontogenic in origin.
The pathologic diagnosis was ameloblastoma type I by Miyazaki-Arai's classification.
During a follow-up of two years and six months, there have been no evidences of a recurrence.
