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.