Metastases in odontogenic cysts: literature review and case presentation.

Malignant tumors in the oral cavity are relatively rare. About 5% of all malignant growths in the body are localized in the oral cavity. The vast majority of oral malignancies are primary tumors with squamous cell carcinoma being the most frequent and sarcomas occurring very seldom. Secondary tumors caused by hematogenous spread arising from a tumor localized elsewhere in the body are extremely rare. About 1% of all oral cancers are metastases to the jawbones and the surrounding soft tissues. Metastases to the jaws are mainly caused by malignant tumors of the breast, lung, kidney, bone, and colon. They occur in the late state of the disease and are regularly detected by staging examinations including scintigraphy. Even more rare are metastases into odontogenic cysts. Odontogenic cysts include dentigerous cysts, periapical or radicular cysts, and the keratocysts-nowadays declared as keratocystic odontogenic tumor. The incidence of odontogenic cysts is about 10% to 15% of all oral biopsies and therefore general dentists are frequently faced with these types of lesions. The aim of this study was to review the literature regarding metastasis into odontogenic cysts and to further highlight this rare entity with the help of a clinical case.