抄録
We describe an unusual case of metastatic choriocarcinoma of the mandible. Sixteen months after odontogenic keratocyst excision, the tumor was found growing in the left molar region of the mandible, the same site of the previously enucleated odontogenic keratocyst. Histopathological examination revealed sheets of atypical cells similar to syncytiotrophoblast or cytotrophoblast, and the tumor was diagnosed as metastatic choriocarcinoma of unknown origin. A whole-body examination was performed; however, the tumor origin was not determined. Surgical excision of the tumor was performed due to rapid growth. One month after tumor excision, multiple tumor masses were detected in both lung lobes by the chest Xray examination. In addition, a high level of serum hCG was detected. The clinical course and histopathological findings, this unusual choriocarcinoma are discussed with referring to the literature.