Logic and clinical significance of the new WHO classification of ameloblastoma in 2017 / 口腔疾病防治

@#A substantial revision of the classification of ameloblastoma was made by the World Health Organization (WHO) in the fourth edition of the Classification of Head and Neck Tumors in 2017, which was based on the review and summary of much clinical research data and prospective evaluation of the latest results of genetic research. The new classification is simpler and more practical. It retains two subtypes, the unicystic type and extraosseous/peripheral type, classifies the remaining types as ameloblastoma (classic), defines metastatic ameloblastoma as a benign tumor and simplifies the classification of ameloblastic carcinoma, which has important guiding significance for clinical diagnosis and treatment. Moreover, the new classification included the latest advances in the genetic research on ameloblastoma, demonstrating that the BRAF gene mutation was found in approximately 60% of ameloblastoma cases. The classification provides a new concept and direction for studying the pathogenesis of ameloblastoma, and BRAF-targeted therapy may be an emerging therapy for some ameloblastoma patients with multiple recurrence or surgical contraindications. This article analyzes the intrinsic logic of these changes via a review of the relevant literature and combination of clinical experiences to better understand the new classification. In 2017, the WHO′s new classification of ameloblastoma summarized the experience and achievements in histopathology and clinical treatment of ameloblastoma in the prior 10 years, indicating that BRAF-targeted treatment may bring new treatment options and hope for patients with recurrent or inoperable ameloblastoma.

Ameloblastic fibro-odontoma masquerading as odontoma.

Ameloblastic fibro-odontoma (AFO) is a rare, benign epithelial mixed odontogenic tumor. It occurs as an intraosseous lesion, generally asymptomatic and more prevalent in children and adolescent. AFO is found on radiographic evaluation of patients with unerupted or impacted teeth in many cases. Histological examination reveals a fibrous soft tissue, islands of odontogenic epithelium and a disordered mixture of dental tissues. The treatment modality in most cases involves conservative surgery with enucleation. We present a case of 13-year-old boy with a missing right central incisor, mimicking-like odontoma on radiograph but proved to be AFO and treated with enucleation with preservation of impacted tooth. There was no recurrence after one year of follow-up. This report discusses the clinical, radiographical, histological features and surgical assessment to preserve the impacted tooth associated with AFO.

A CLINICAL ANALYSIS OF BENIGN ODONTOGENIC TUMOR