Metastatic tumors of the oral region are rare, representing about 1 % of malignant tumors in the oral cavity. In this article, we report a case of carcinoma of the sigmoid colon that metastasized to the maxillary gingiva and review of literature. A 69-year-old man underwent extraction of the right first and second molars of the maxilla, and a rapidly proliferating lesion developed at the site. The patient had previously undergone surgical excision of adenocarcinoma of the sigmoid colon. Histological examination of the oral lesion revealed adenocarcinoma similar to the previous lesion in the colon. Moreover, the serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 were elevated. These findings suggested that the oral lesion was a metastatic adenocarcinoma from the sigmoid colon. Although computerized tomographic scans showed metastatic lesions of the liver and lung, the gingival tumor was excised to improve dysphagia induced by the rapidly growing tumor. He died of respiratory arrest 4 months after surgery.
