RESUMEN
Ameloblastoma is a benign locally aggressive odontogenic tumor of epithelial origin with unlimited growth capacity. Cervical lymphoepithelial cyst is a developmental cyst located in the superior-lateral region of the neck with treatment consisting of surgical excision, which presents low recurrence rates. This article reports the case of patient J.G.S.L., 24 years old, female, who reported to the service with a histopathological evaluation compatible with intraosseous mandibular ameloblastoma. On physical examination, a nontender swelling was palpable along the body of left mandible where the ameloblastoma was located, with a fluctuant region detected just below it. Imaging exams confirmed the suspicion of two independent lesions. The treatment plan consisted of two stages: first, mandibular resection of the area affected by the ameloblastoma, followed by reconstruction with a titanium plate simultaneous to excisional biopsy of the as yet undiagnosed lesion, both through intraoral access; second, mandibular reconstruction with iliac crest graft. Histopathological examination of the second lesion indicated a diagnosis of cervical lymphoepithelial cyst, being the first case in the literature with these concomitant lesions. Currently, the patient is in her third postoperative year with no signs of recurrence.