Adenoid ameloblastoma with dentinoid and ghost cells. A composite odontogenic tumour: a rare case report and review of the literature

Diagnostic Enigma of Adenoid Ameloblastoma: Literature Review Based Evidence to Consider It as a New Sub Type of Ameloblastoma

Adenoid ameloblastoma is a hybrid odontogenic tumour showing histopathological features of both ameloblastoma and adenomatoid odontogenic tumour (AOT), with approximately 40 cases reported in the literature. The aims of the report are to illustrate the diagnostic challenges of adenoid ameloblastoma using three new cases and to analyze evidence in literature to consider adenoid ameloblastoma as a new sub type of ameloblastoma. A literature review was performed with the key words-adenoid ameloblastoma, hybrid/composite odontogenic tumours, hybrid ameloblastoma and adenomatoid odontogenic tumour, ameloblastoma with inductive changes, dentinoid and dentinoma to select the cases compatible with the diagnosis of adenoid ameloblastoma. Out of the 40 cases reported in literature, 31 cases with sufficient information and 3 new cases were analyzed. Out of the 34 adenoid ameloblastomas majority of tumours (76.5%) occurred in adults with age ranging from 25 to 55 years. Slight female predilection with a male:female ratio of 0.9:1 was observed. Approximately, 64.7% occurred in the mandible. Radiologically, 82.4% of adenoid ameloblastomas presented as radiolucent lesions while 47.1% occurred with ill-defined margins and cortical perforation at diagnosis. Histopathologically, 70.8% of tumours presented as plexiform ameloblastomas, while duct like structures/glandular structures were the commonest feature supportive of adenomatoid odontogenic tumour observed in overwhelming majority of 95.9% of adenoid ameloblastomas. 91.6% of tumours showed inductive change in the form of dentinoid. Further, 45.4% of the tumours developed at least one recurrence following surgical excision. The report presents literature review based evidence to show the existence of adenoid ameloblastoma, which is demographically similar to conventional ameloblastoma but with histopathological differences and presenting with higher rate/multiple recurrences, indicating its biological aggressiveness. Thus, we would like to propose the inclusion of adenoid ameloblastoma as a sub type of ameloblastoma in the next revision of the WHO odontogenic tumour classification.

Adenoid ameloblastoma in the posterior maxilla: a case report and review of the literature

INTRODUCTION

Adenoid ameloblastoma is a rare benign odontogenic tumor that favors a slight predilection for male patients, fourth and fifth decades of life, and posterior regions of the jaws. To date, less than 40 cases have been reported in the English language literature. The radiographic aspects of adenoid ameloblastoma vary from unilocular and well-defined lesions to diffuse and multilocular lesions. Most of the lesions exhibit a radiolucent image and are usually large, with a mean size of 3.5 cm. Microscopically, pseudoductal structures composed of columnar cells in a palisaded arrangement formed from the parenchyma of the tumor were observed.

CASE PRESENTATION

We describe a case of adenoid ameloblastoma in a 54-year-old woman, who presented with no symptoms. Panoramic radiography showed a well-circumscribed, unilocular radiolucency in the left posterior maxilla.

CONCLUSION

As odontogenic tumors are rare, some entities are infrequently encountered, making the diagnosis more difficult. Clinicians, oral and maxillofacial surgeons and oral pathologists should be familiar with the adenoid ameloblastoma and its differential diagnosis for accurate diagnosis and management.