Extrafollicular Adenomatoid odontogenic tumour presenting as a periapical lesion: Report of a rare entity

Adenomatoid odontogenic tumour (AOT) has been known to the pathologists for the past 100 years as a benign slow growing tumour. Histologically, this tumour has a predominantly solid component and very few case reports have described the cystic nature of AOT. In the present case we review the literature of extrafollicular AOT presenting as a periapical disease and add to the literature a case of cystic extrafollicular AOT in a 17-year-old patient, initially diagnosed as a radicular cyst. Radiographically extrafollicular AOT frequently resembles other odontogenic lesions such as residual, developmental lateral periodontal or radicular cyst, however histopathological findings of this tumour are quite characteristic and present few diagnostic problems. Correlation of clinical and radiological information with histological features is important in the diagnosis of odontogenic cysts and tumours, to decrease the incidence of misdiagnosis for such cases and this in turn will help in preventing recurrences.