Assessment of Bone and Soft Tissue Margins in Resection of Mandibular Ameloblastoma: An Institutional Series

Abstract

<h3>Introduction</h3> The treatment of gnathic ameloblastoma remains controversial. When resection is undertaken, a planned linear bone margin of at least 1.0 cm is often recommended for mandibular tumors. For cases in which tumor has extended beyond bone, inclusion of the adjacent anatomic barrier is recommended, however little attention has been devoted to the margin reporting of non-osseous margins. <h3>Materials and Methods</h3> Emory University records were searched for patients undergoing resection for ameloblastoma between 1/1/2020 and 3/01/2021. Twenty-one consecutive patients underwent surgical resection during the fourteen-month interval. In six cases, specimen fragmentation precluded margin evaluation. In three cases, only rare tumor islands remained microscopically in the resection specimen after initial biopsy inadvertently removed much of the lesion. The twelve remaining patients formed the study cohort. <h3>Results</h3> Patients ranged from 22 to 78 years of age, and 6 were male. Segmental mandibular resection was performed in 10 cases and marginal mandibular resection accomplished in 2. Average tumor size was 4.9 cm. In 10 of 12 cases, ameloblastoma extended beyond the mandibular bone. In all ten cases, the soft tissue margin was grossly identified as the margin nearest to tumor. Microscopically, soft tissue margin clearance measured 1.0 mm or less and in one, tumor involved the soft tissue margin. All bone margins measured 0.6 cm or greater from tumor, with 10 of 12 mandibular bone resection margins showing a linear distance of 1.0 cm or more from tumor. <h3>Conclusion</h3> In ameloblastoma perforating bone, soft tissue margins are most likely to represent the closest margin. Narrow clearance of soft tissue margins in ameloblastoma may be related to the lack of a specific guiding measurement in the literature. Close soft tissue margins can be identified grossly, and the clinical significance of ample bone margin clearance in the setting of narrow soft tissue clearance remains uncertain.