A clinicopathological study of malignant odontogenic tumours.

AIMS: Malignant odontogenic tumours (MOTs) are rare neoplasms occurring primarily within the jaw. The objective of this study was to determine the incidence, demographics and clinicopathological features of the MOTs from two institutions. METHODS AND RESULTS: The records of the Department of Oral Pathology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand and the Department of Oncology and Diagnostic Sciences, Dental School, University of Maryland, Baltimore, USA were searched from 1991 to 2010; we identified 17 cases of previously diagnosed MOTs. All cases were reviewed independently of the previous diagnosis by two blinded oral pathologists and reclassified based on the 2005 World Health Organization classification of head and neck tumours. In this study we describe in detail these 17 cases which presented with an average age of 50.29 years and a male to female ratio of 2.4:1. These cases included five ameloblastic carcinomas, four atypical ameloblastomas, three primary intraosseous squamous cell carcinomas, three intraosseous mucoepidermoid carcinomas and two clear cell odontogenic carcinomas. All cases were treated by surgical resection and one patient with ameloblastic carcinoma received postoperative radiotherapy. CONCLUSIONS: Malignant odontogenic tumours are considered rare central odontogenic lesions. Awareness of their existence, rapid diagnosis and successful treatment using surgery, radiation and/or chemotherapy is critical to patient survival.

Clear cell odontogenic carcinoma. A review.

INTRODUCTION: Clear cell odontogenic carcinoma (CCOC) is described as an exceptional and hard to diagnose malignant tumor which was first reported by Hansen in 1985. The purpose of this review article is to show that CCOC is a not that rare entity and to discuss its various aspects in order to enhance the diagnosis. MATERIAL AND METHODS: A search in the English language literature was performed using the Scopus, ScienceDirect, PubMed and Medline databases between 1985 and 2016. Data were collected on epidemiologic, clinical, radiographic, histological, immunohistochemistrical, cytogenetic, management, follow-up and prognosis features of CCOC. RESULTS: Sixty-five studies from which a total of 95 case reports were included in the review. CCOC was generally seen in the fifth decade and the most common site was mandibular. The most frequently found symptoms were swelling, tooth mobility and pain. Radiologically, the image was radiolucent and could look like a cyst or a periodontal lesion. In situ hybridization techniques frequently expressed a gene fission of EWSR1. The treatment was mostly a radical surgical excision of the tumor with or without adjuvant radiotherapy or chemotherapy. CCOC showed high rates of recurrence and mortality related with the presence of distance metastasis. DISCUSSION: Fission of EWSR1 gene could be the main element it the diagnosis of CCOC. A multidisciplinary approach, including a radiologist, pathologist and an oral & maxillofacial surgeon may be helpful in the evaluation and management of these lesions. With 95 reports found in English literature, we cannot say that CCOC is extremely rare anymore.

Clear cell odontogenic carcinoma: report of 7 new cases and systematic review of the current knowledge.

OBJECTIVE: The goal of this study is to describe 7 cases of clear cell odontogenic carcinoma among a Brazilian population and compare these data with a systematic review of the English-language literature. STUDY DESIGN: Descriptive statististics were used to compare the clinicopathologic data gathered retrospectively with those compiled from a review. Tumor sections were immunostained for Ki-67, p16, p53, and cytokeratins (CKs) 7, 8, 14, 18, and 19. Log-rank tests were performed for survival analysis. RESULTS: Most cases occurred in the posterior mandible (5/7, 71.4%), and recurrence was diagnosed in all treated patients. Metastatic disease occurred in 2 patients (28.6%). Tumors were focally positive for CKs 7, 8, 14, and 18 and diffusely positive for CK19, p53, and p16. The mean number of Ki-67-positive cells was 35.2 cells/high-power field. Our systematic review provided evidence that tumor size (P = .046), histologic pattern (P = .034), regional metastasis (P = .001), distant metastasis (P = .001), and local recurrence (P = .05) were of significant prognostic value. CONCLUSIONS: This study has contributed to improved characterization of clear cell odontogenic carcinoma, which is an aggressive odontogenic malignant neoplasm diagnosed mainly in the posterior mandible of middle-aged women and typically at an advanced stage. Radical surgical procedures remain the gold standard treatment.