Odontogenic Cysts and Tumors

Abstract

Odontogenic cysts and tumors are common pathologic entities of interest to oral and maxillofacial surgeons. While these lesions are commonly reported in adults, their incidence in the pediatric population is compelling and warrants review. Odontogenic cysts have been subclassified as developmental and inflammatory, with the cysts of interest including the odontogenic keratocyst, calcifying odontogenic cyst and the glandular odontogenic cyst as part of the former subclassification. Odontogenic tumors have been subclassified as those of odontogenic epithelium; those of odontogenic epithelium with odontogenic ectomesenchyme +/− dental hard tissue formation; and those of odontogenic ectomesenchyme +/− included odontogenic epithelium. This subclassification is of significance from the standpoint of histogenesis rather than from the standpoint of treatment or age at diagnosis. For example, each subclassification of the odontogenic tumors contains entities that occur in adult and pediatric patients, and entities that may be cured with enucleation and curettage surgeries as well as those that require resection for surgical cure. This notwithstanding, many individual odontogenic tumors have subtle differences regarding their presence in pediatric patients, and this represents the focus of this presentation. The odontogenic keratocyst is the most interesting odontogenic cyst in the adult and pediatric populations. While treatment is the same in both populations, the presence of Nevoid Basal Cell Carcinoma Syndrome is important to diagnose in an expedient fashion. Besides the presence of multiple odontogenic keratocysts in 50% or greater frequency in this syndrome, the odontogenic keratocysts associated with this syndrome peak about one decade earlier compared to sporadic cysts which are more commonly noted in the adult population. As such, diagnosis of these cysts in the pediatric age group may permit an early diagnosis of this syndrome. Perhaps the most controversial odontogenic tumor is the ameloblastoma. It has received due attention in our specialty’s literature in adult patients as well as in children. Differences between pediatric and adult ameloblastomas include a higher percentage of the unicystic variant diagnosed in children. Observed similarities between these tumors in children and adults include the need to provide resection for the solid or multicystic ameloblastoma variant so as to provide surgical cure. Other epithelial odontogenic tumors and ectomesenchymal tumors, including the Pindborg tumor and the odontogenic myxoma, respectively, show a wide age range of incidence, with a mean age of approximately 30 years. Nonetheless, cases have been diagnosed in the first and second decades of life such that these tumors should be considered in differential diagnoses of jaw lesions in children. Perhaps the subclassification of odontogenic tumors most applicable to the pediatric population is the mixed odontogenic tumors, including the ameloblastic fibroma, ameloblastic fibro-odontoma, and the odontoma. There has been considerable debate as to the interrelationship of these three entities. In fact, the continuum concept has been suggested indicating that this interrelationship begins developmentally with the ameloblastic fibroma and ends with the odontoma, with the ameloblastic fibro-odontoma as an intermediate stage in this continuum. This concept is not widely accepted, however, due to the ameloblastic fibroma being observed at a variety of ages.