Surgical Treatment for a Huge Maxillary Ameloblastoma via Le Fort I Osteotomy: A Case Report

Abstract

Ameloblastomaa are odontogenic benign tumors with epithelial origin, which are characterized by slow, aggressive, and invasive growth. Most ameloblastomas occur in the mandible, and their prevalence in the maxilla is low. A 27-year-old male visited our clinic with a chief complaint of the left side nasal airway obstruction. Three-dimensional computed tomography showed left maxillary sinus filled with a mass. Except for the perforated maxillary left edentulous area, no invaded or destructed bone was noted. The tumor was excised via Le Fort I osteotomy. The main mass was then sent for biopsy and it revealed acanthomatous ameloblastoma. The lesion in the left maxillary sinus reached the ethmoidal sinus through the nasal cavity but did not invade the orbit and skull base. The tumor was accessed through a Le Fort I downfracture in consideration of the growth pattern and range of invasion. The operation site healed without aesthetic appearances and functional impairments. However, further long-term clinical observation is necessary in the future for the recurrence of ameloblastoma. Conservative surgical treatment could be the first choice considering fast recovery after surgery and the patient's life quality.

Fig. 3. Histological findings. (A) H&E staining (×20). At low magnification, most of lining epithelium showed marked keratinization in the center and upper portions of the epithelial islands. (B) H&E staining (×40). The tumor is composed of characteristic epithelium of the ameloblastoma in the fibrous stroma. The basal cells of these islands (arrowhead) are columnar and hyperchromatic and show a palisading pattern. The central part of the islands (black arrow) shows squamous differentiation. Marked keratinization is noted in this area (white arrow). (C) H&E staining (×400). Palisaded cells and Columnar cells have a tendency for the nucleus to move from the basement membrane to the opposing end of the cell, a process referred to as reverse polarization. (D) H&E staining (×100). Squamous differentiated cells are benign. Marked keratinization with parakeratosis is noted.

Fig. 1. (A) Patient’s facial photograph. No significant facial deformities were present. (B) Three-dimensional computed tomography (CT) view. (C) Axial view in enhanced CT. (D) Coronal view in enhanced CT. (E) The tumor perforated the left second molar area mucosa and protruded into the oral cavity. (F) Coronal view in magnetic resonance imaging showed mucosal thickening at the patient’s left ethmoidal sinus and the thickened mucosal margin had a boundary with the mass.

Fig. 2. (A) Intraoperative clinical photograph. Lesion was excised via the Le Fort I osteotomy approach. (B) Perforated gingival mucosa covered with a pedicled buccal fat pad. (C) The tumor also obstructed the nasal airway. (D) Excised tumor. The mass was about 4.5 cm×4 cm×2.5 cm in size.

Fig. 4. (A) Follow-up panoramic radiograph obtained 3 months postoperatively. No bony healing was observed but the left sinus haziness appears to have been resolved. (B) Follow-up intraoral photograph obtained 1 month postoperatively. The perforated mucosa covered with the pedicled buccal fat pad shows good healing without a fistula. (C, D) Followup computed tomography scans in the coronal and axial views obtained 3 months postoperatively. No signs of recurrence was observed.