Discussion and review of literature
The term unicystic ameloblastoma refers to a cystic lesion that has clinical features of a jaw cyst but an histological examination shows a typical ameloblastomatous epithelium lining part of the cystic cavity with or without luminal and mural growth. Unicystic ameloblastoma was first described by Robinson and Martinez . These lesions represent a less aggressive type of ameloblastoma and therefore should have a better prognosis. Unicystic ameloblastoma are often observed in younger patients with approximately 50% of all such tumors diagnosed during the second decade of life. The mean age of presentation is 40 years. In a study carried out by Rosenstein et al. , the size of the lesions varied from 2 to 8 cm and in study by Bataineh  from 5 to 15 cm in diameter. However, in our case it was approximately 15×15 cm.
The treatment modalities of ameloblastomas according to Bataineh  can be broadly classified as conservative and radical. Feinberg and Steinberg  mentioned enucleation and curettage as conservative approaches. They also have devised a surgical protocol for the management of solid/multicystic ameloblastomas and are of the opinion that it may be modified to take into account the patient's age, anatomic location, and whether it is a primary presentation or a recurrence. Gardner and Pecak  stressed on several important factors that have to be considered in defining the treatment of ameloblastoma.
It is essential to distinguish between the three clinical types of ameloblastomas, the intraosseous solid or multicystic lesion; the well-circumscribed unicystic type; and the rare peripheral extraosseous ameloblastoma, because they require different forms of treatment.
Unicystic ameloblastoma in which the tumor extends into the lumen of the cyst or involves the lining can be expected to be removed completely by enucleation, whereas the treatment is inadequate if the tumor has invaded the outer part of the fibrous connective tissue wall of the cyst.
Ameloblastoma in the posterior part of the maxilla should be treated more extensively than similar lesions of the mandible because of the proximity of the posterior maxilla to vital structures. There are very few well-controlled studies comparing the efficacy of various modes of therapy, particularly, with respect to the variants of ameloblastoma.
Gardner and Pecak  stressed the fact that unicystic ameloblastoma, in which the tumor has proliferated into the lumen, can be expected to be cured by enucleation because the fibrous connective tissue wall of the cyst completely surrounds the tumor and provides an adequate margin of the uninvolved tissue. They also agreed that those unicystic ameloblastomas in which the periphery of the connective tissue wall of the cyst is involved should be treated by marginal resection. They also suggested that marginal resection should be used if the tumor involved the posterior maxilla.
Feinberg and Steinberg  are of the opinion that if the periphery of the connective tissue wall of the cyst is involved by the tumor (both in the maxilla and the mandible), then it is an indication to treat the lesion aggressively. Olaitan and Adekeye  in their study showed that when the lesion is confined within the bone, enucleation or marginal resection often can be successful.
However, when there is bony proliferation, full-thickness resection should be performed. Nakamura et al.  stated that wide resection of the jaw is usually the recommended treatment for ameloblastoma, should priority be given to recurrence rate. However, radical surgery often means that the patients have serious complications, including facial deformity, masticatory dysfunction, and abnormal jaw movements.
With regard to the characteristics of ameloblastoma, the priority of the treatment method should be addressed from the points of morbidity and quality of life of the patients, observing that the recurrence rate is not always the primary factor; but, because of late recurrence of some lesions, many investigators recommend long-term follow-up in all patients up to 10 years. Enucleation with long-term follow-up is adequate for tumors that have proliferated into the lumen of the cyst, but more extensive surgery is recommended for those that involve the periphery of its fibrous connective tissue wall .
In our patient though, it was proved to be unicystic ameloblastoma, in view of the aggressive nature of the tumor involving the maxilla and the mandible and the presence of extraoral sinus. In addition, because of the fact that the tumor involved the surrounding connective tissue, hemimandibulectomy and resection of the maxillary alveolus seem justified. The patient was followed up for 6 years with no recurrence of the lesion.
1. Robinson L, Martinez MG. Unicystic ameloblastoma: a prognostically distinct entity Cancer. 1977;40:2278–2285
2. Rosenstein T, Pogrel MA, Smith RA, Regezi JA. Cystic ameloblastoma-behavior and treatment of 21 cases J Oral Maxillofac Surg. 2001;59:1311–1316 discussion 1316–1318.
3. Bataineh AB. Effect of preservation of the inferior and posterior borders on recurrence of ameloblastomas of the mandible Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2000;90:155–163
4. Feinberg SE, Steinberg B. Surgical management of ameloblastoma. Current status of the literature Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1996;81:383–388
5. Gardner DG, Pecak AM. The treatment of ameloblastoma based on pathologic and anatomic principles Cancer. 1980;46:2514–2519
6. Olaitan AA, Adekeye EO. Clinical features and management of ameloblastoma of the mandible in children and adolescents Br J Oral Maxillofac Surg. 1996;34:248–251
7. Nakamura N, Higuchi Y, Tashiro H, Ohishi M. Marsupialization of cystic ameloblastoma: a clinical and histopathologic study of the growth characteristics before and after marsupialization J Oral Maxillofac Surg. 1995;53:748–754 discussion 755–756.
8. Gardner DG, Corio RL. Plexiform unicystic ameloblastoma. A variant of ameloblastoma with a low-recurrence rate after enucleation Cancer. 1984;53:1730–1735
Keywords:© 2011 Egyptian Associations of Oral and Maxillofacial Surgery
HIV; mandible; maxilla; unicystic ameloblastoma