Pearls and pitfalls in the management of ameloblastoma

Abstract

Ameloblastomas are benign tumors of the maxilla and mandible originating from odontogenic Odontogenic Tumor epithelium involved with tooth formation. They preferentially occur in the mandible (75%) and are most commonly found in the third molar area of either jaw. Clinically, they present as asymptomatic expansions of the jaw Jaw tumors bones. Radiographically they appear as well-defined, expansile uni- or multilocular radiolucencies. Diagnosis is typically made with an incisional biopsy. Although benign, they can be locally aggressive and invade and resorb bone and soft tissue. However, they are unable to undergo true perineural invasion. Very rarely, ameloblastomas may undergo malignant transformation into either ameloblastic carcinoma (invasive) or malignant ameloblastoma (metastatic). The two most common histopathologic patterns are follicular and plexiform, both of which demonstrate columnar cells with nuclei polarized away from the basement membrane. Because enucleation and curettage have a 70-85% recurrence rate and microscopic disease has been found to extend up to 8 mm beyond radiographic disease, ameloblastomas are treated by bone resection with 1.0-1.5 cm margins. When adequately resected, cure rates are 98%. The molecular biology of ameloblastoma is an area of active research. V600E BRAF mutations have been identified as a common mutation in mandibular ameloblastomas. The clinical significance of this finding is still being investigated, but it is intriguing because approved targeted therapies for this mutation are already on the market. Case reports of using BRAF/MEK inhibitors to treat ameloblastomas, ameloblastic carcinomas, and malignant ameloblastomas have reported promising preliminary results. The purpose of this chapter is to review pearls and pitfalls in the surgical management of ameloblastoma.