Ameloblastoma is the most common epithelial odontogenic tumor. It may show 
locally invasive behavior resulting in recurrence and malignancy. Therefore, 
appropriate diagnosis of this tumor is necessary. The aim of this study was to 
evaluate clinicopathological characteristics of ameloblastomas in an Iranian 
population. We present a 40-year retrospective study of patients diagnosed from 
1971 to 2010 in the Department of Oral and Maxillofacial Pathology, Faculty of 
Dentistry, Mashhad, Iran. Information gathered from patient records included 
age, gender, tumor location and histologic type. The frequency of odontogenic 
tumors among all lesions was 2.08% and ameloblastoma with 88 samples 
demonstrated the greatest prevalence (41.5%). Regarding gender, 60% of samples 
occurred in males. The mean age of studied patients was 33.02± 15.74 years with 
a peak of occurrence in the third decade of life. The most frequent location of 
tumor was the mandibles (93.2%). Eighty five (96.6%) tumors were recorded as 
benign and 3 (3.4%) as malignant. Of benign tumors, 62 (72.9%), 20 (23.5%) and 3 
(3.6%) cases were of conventional, unicyctic and peripheral types, respectively. 
In contrast to most previous studies, the most common histologic subtype in the 
present study was plexiform. Knowledge of the incidence of ameloblastoma and its 
clinicopathologic features including most common location, gender and age 
distribution in different ethnogeographic backgrounds is necessary for accurate 
diagnosis and proper treatment.