The pathogenesis of oral choristomas

Failures in the normal course of embryonic development of the neural tube may give rise to a great variety of defects as the head and neck region develops. Such abnormalities may be manifested in the form of choristomas. The term choristoma applies to a cohesive tumor like mass consisting of normal cells in an abnormal location. Because of their benign tumor like growth and also their developmental pathogenesis, these need to be differentiated from neoplasms. Choristomas should also be distinguished from hamartomas which are tumor like malformations composed of a focal overgrowth of mature normal cells located where they are normally found. Since choristomas may arise from various tissues, mimicking various neoplasms, this review highlights the pathogenesis of different types of choristomas in the oral cavity.