ODONTOGENIC TUMORS: A 50-YEAR EXPERIENCE

Objectives Odontogenic tumors are a heterogeneous group of lesions of diverse clinical behavior and histopathologic types, ranging from hamartomatous lesions to malignancy. They are derived from epithelial and mesenchymal elements of the tooth-forming apparatus so they are unique to the jaws. The last update of these tumors was published in 2017 January. According to this classification, benign odontogenic tumors are classified as follows: Epithelial, mesenchymal (ectomesenchymal), or mixed depending on which component of the tooth germ gives rise to the neoplasm. Malignant odontogenic tumors are quite rare and named similarly according to whether the epithelial or mesenchymal or both components are malignant. Epidemiological data on odontogenic tumors within in Turkey is scarce. Our aim is to determine the incidence of odontogenic tumors according to the new classification within a Turkish population. These tumors were identified using the pathology files, Istanbul, about a 50-year period. Findings Over a thousand cases of odontogenic tumors were diagnosed in the Oral and Maxillofacial Pathology Unit between 1971-2018. The cases were reviewed and reclassified histopathologically in accordance with the 2017 WHO classification of head and neck tumors. The most common three tumors were ameloblastoma (n:366, including unicystic and peripheral ameloblastomas), odontoma (n:335, both complex and compound), and odontogenic myxoma/fibromyxoma (n:190), respectively. Malignant and peripheral odontogenic tumors are a small proportion of this series. The mean age is about 32 and there is a slight female predilection. The most common site is molar region of the mandible, followed by the anterior mandible and the anterior maxilla. Conclusions This is one of the largest series of odontogenic tumors to be described from the Europe. The location, site, gender and age of the patients are similar to that in other populations, however there are some differences about the frequency of the tumors types.