下顎枝前内方部に発生した周辺性エナメル上皮腫の1例

抄録

Peripheral ameloblastoma is an uncommon variant of ameloblastoma occurring in the extraosseous region, which accounts for only 1 % to 5 % of all types of ameloblastomas. The most frequent sites of peripheral ameloblastoma are the upper and lower gingiva, but the anteromedial part of the mandibular ramus is not a common site of this tumor. We report a case of peripheral ameloblastoma arising in the anteromedial part of the right mandibular ramus of a 59-year-old woman who noticed a painless mass during swallowing. Computed tomographic and magnetic resonance images showed a well-circumscribed mass in the anteromedial part of the mandibular ramus. We performed an excisional biopsy with a rim of surrounding normal tissue under general anesthesia. Histopathologically, the mass was diagnosed as a plexiform type peripheral ameloblastoma. There was no evidence of recurrence at 45 months of postoperative follow-up.