Anterior Mandibular Mural Unicystic Ameloblastoma Crossing the Midline: A Rare Case with Histopathological Diagnostic Challenges

Abstract

Introduction: Ameloblastomas are among the most common locally aggressive benign odontogenic tumors of the jaws. They predominantly arise in the posterior mandible, whereas anterior mandibular involvement is uncommon. Ameloblastomas are classified into multicystic, unicystic, peripheral, and desmoplastic variants. The unicystic subtype is reported less frequently than conventional ameloblastoma. It typically presents as a pericoronal radiolucency that mimics a dentigerous cyst, but it may also occur in interradicular, periapical, or edentulous areas. Radiographically, it usually appears as a unilocular radiolucency, whereas multilocular presentations are infrequent. This report presents a case of mural unicystic ameloblastoma, a subtype associated with a higher risk of recurrence. Case Presentation: A 42-year-old woman presented with a 2-month history of painless swelling in the anterior mandible. Clinical examination revealed a 3 x 5 cm hard, fixed mass without purulent discharge, inflammation, or paresthesia. Panoramic radiography showed a well-defined mixed radiolucent-radiopaque lesion in the anterior mandible, extending from the right first premolar to the left second premolar and causing root displacement and resorption. Computed tomography confirmed cortical expansion and thinning, as well as dystrophic calcifications. The provisional diagnosis favored a benign odontogenic tumor, and incisional biopsy suggested ameloblastic fibroma. Following segmental mandibular resection with a 1.5-cm safety margin, comprehensive histopathological analysis confirmed mural unicystic ameloblastoma. No clinical or radiographic evidence of recurrence was observed during the short 6-month follow-up period. Conclusions: A definitive diagnosis requires thorough histological evaluation of the entire specimen because clinical and radiographic features alone are insufficient for accurate preoperative prediction. Lesions with potentially aggressive features require expert pathological assessment to ensure accurate diagnosis and optimal treatment planning.