Prognostic evaluation of metastasizing ameloblastoma: A systematic review of reported cases in literature

Ameloblastoma is a benign odontogenic tumor which undergoes malignant transformation to ameloblastic carcinoma. However, rarely it metastasizes without undergoing cytological malignant changes, an entity referred to as Metastasizing Ameloblastoma (MA). Through this study, we aimed to review cases of MA reported since 2000 to explore the impact of clinico-demographic variables on its prognosis. Based on PRISMA guidelines, a review of relevant literature from PubMed/Medline, Science Direct and Cochrane database was performed from January 2000 to March 2019. A total of 65 cases were considered for further evaluation as per predefined inclusion and exclusion criteria. Results showed that lungs followed by lymph nodes were the most common sites for benign metastatic deposits. Multiple recurrences and inadequate surgical removal increase the probability of distant metastatic spread. Despite having benign cytological features, tumor recurrence and metastasis were associated with an unfavorable clinical outcome in MA.