aDepartments of OMFS
bGeneral Surgery, M.S. Ramaiah Dental College and Hospital, Bangalore, Karnataka
cDepartment of OMFS, Vishnu Dental College and Hospital, Bhimavaram, Andhra Pradesh
Correspondence to Raichoor Anil Kumar, MDS, Room no: 2, Department of OMFS, Vishnu Dental College and Hospital, Bhimavaram, AP 534202, India Tel: +91 9908684674; e-mail: firstname.lastname@example.org
Received October 5, 2010
Accepted January 16, 2011
Unicystic ameloblastoma, described by Robinson and Martinez, is one of the variants of ameloblastoma. Unicystic ameloblastoma is an intraosseous tumor commonly seen in younger people. Simple enucleation and application of Carnoy's solution are generally the recommended treatment of choice. Sometimes, they might show clinical aggressiveness and hence radical resection is suggested. A rare case of unicystic ameloblastoma occurring in the mandible and maxilla in an HIV-positive patient is reported and a review of the literature regarding the treatment of such lesions is discussed.
Ameloblastoma is a relatively uncommon, aggressive but benign epithelial neoplasm of odontogenic origin, which accounts for approximately 1% of all jaw tumors. It behaves as a locally invasive odontogenic tumor that rarely metastasizes and usually presents as a slow-growing painless swelling. In 1977, Robinson and Martinez  identified a subset of ameloblastoma called as unicystic ameloblastoma, which accounts for approximately 10–15% of all intraosseous ameloblastomas. It occurs in a relatively younger age group with a less aggressive clinical behavior than multicystic ameloblastoma. Ameloblastomas have a high rate of local recurrence than noncystic. The treatment modalities of ameloblastomas include conservative curettage, electrocautery, cryosurgery, radiotherapy, and radical excision. Although the unicystic variant can be treated conservatively with curettage and peripheral osteotomy, a radical approach is advised if there is invasion into adjacent tissue. Usually, patients who are HIV positive develop neoplasm such as Kaposi's sarcoma and non-Hodgkin's lymphoma because of immune suppression; however, no case has been reported in the literature regarding HIV-positive patient presenting with unicystic ameloblastoma in both the maxilla and the mandible.
Report of a case
A 19-year-old female patient reported to the department of oral and maxillofacial surgery at M.S. Ramaiah Dental College and Hospital, Bangalore, with the chief complaint of a large swelling on the left side of the face for the past 6 months. There was an extraoral sinus on the left cheek discharging pus (Fig. 1). The patient had no difficulty in mastication and speech, was a known case of HIV-status individual, and had no other medical illness at the time of presentation or other signs of AIDS-related disorders.
On examination, the nutritional status of the patient was satisfactory. On the left side of the face, a large diffuse dome-shaped swelling measuring approximately 15×15 cm was present extending from the infraorbital margin to the upper third of neck. Posteriorly, it extended to the preauricular region, and inferiorly crossed the midline, resulting in deviation of the chin, nose, and angle of mouth. The overlying skin was stretched and a healing sinus was present with a mouth opening of approximately 1.5 cm. On palpation, the swelling was hard, arising from the mandible (Fig. 2). On intraoral examination, ulceration was found involving the left buccal, labial, and lingual sulci, up to the retromolar area with expansion of both the cortices of mandible extending up to the maxillary alveolus. Soft palate and tongue were pushed to the opposite side. Mandibular posterior teeth on the left side were missing and 32, 33, and 34 were displaced. The patient gave a history of biopsy elsewhere and the slides were reviewed, which showed features of unicystic ameloblastoma (Figs. 3 and 4). Computed tomographic scanning showed a large radiolucent lesion on the left side involving the entire mandible and maxilla with displaced teeth (Fig. 5). Patient's routine blood and urine investigations were within normal limits. CD4 count was 1345 cells/μl. With regard to the patient's general health and the extent of the soft tissue involvement, radical resection was planned under general anesthesia.
Hemimandibulectomy with resection of maxillary alveolus and primary closure was performed. (Fig. 6). The patient's postoperative recovery was uneventful; the resected specimen was subjected to histopathological examination and showed features of unicystic ameloblastoma (Fig. 7). Routine antibiotics and analgesics were prescribed, and wound healing was satisfactory. The patient was discharged 2 weeks after surgery and since then has been followed up on a regular basis.
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.
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