Intraosseous sebaceous adenocarcinoma of the maxilla

Abstract

Primary intraosseous salivary malignancies are rare. The adenoid cystic adenocarcinoma, adenocarcinoma not otherwise specified, acinic cell adenocarcinoma and the epithelial-myoepithelial carcinoma have all been reported within the jaws. The mucoepidermoid carcinoma is by far the most common tumor in this setting accounting for 2%-4% of all mucoepidermoid carcinomas. An intraosseous sebaceous adenocarcinoma has never been reported. We document a case of sebaceous adenocarcinoma of the maxilla in a 56-year-old woman who presented with a painful swelling of the right face. CT scans showed an expansile, osteolytic tumor of the right maxilla. An exploratory biopsy revealed the tumor to be expanding and eroding the cortical plates including the floor of the sinus. The histopathology was consistent with a sebaceous adenocarcinoma. The sebocytes expressed EMA and CD15. The basaloid cells were CD15 negative. The tumor was treated with a wide local resection. Post-surgical healing was uneventful and patient is being monitored regularly for recurrences. Prognosis of any tumor originating intraosseously is worse than its soft tissue counterpart. Extraocular sebaceous adenocarcinomas are low grade malignancies which can recur locally. As this is the first report of an intraosseous/central sebaceous adenocarcinoma, prognostication could be inaccurate and therefore long-term follow-up is highly recommended.