Intraoral sebaceous carcinoma metastatic to the lung and subcutis: Case report and discussion of the literature.

BACKGROUND Intraoral sebaceous carcinoma is a rare form of sebaceous carcinoma with only 9 published cases in the world literature to date. We present a 10th case of intraoral sebaceous carcinoma located in the anterior maxillary gingiva with metastases to the lung and subcutis and discuss 3 possible etiologies for this unique presentation. METHODS We analyze the clinical presentation, pathology, histology, and genetic testing for a single case study and review relevant literature. RESULTS The histologic findings of the lung tumor and surgical excisions of the tumors in the gingiva and subcutis suggest the gingiva is the primary site. There is no evidence for the genetic abnormalities consistent with Muir-Torre syndrome. CONCLUSION The histologic findings suggest the oral cavity is the most likely site of tumor origin. This is the first case of intraoral sebaceous carcinoma reported to arise in the gingiva as well as to spread to cutaneous sites.