Signet-ring cell adenocarcinoma metastatic to the maxillary sinus

Signet-ring cell variant is a rare type of adenocarcinoma that has been reported in the paranasal sinuses and in other areas, most commonly the gastrointestinal tract. We describe a patient with signet-ring cell adenocarcinoma of the maxillary sinus who had dental and facial pain. Further evaluation revealed that the lesion was metastatic from an esophageal primary lesion. The unusual nature of this cell type and the importance of careful evaluation to exclude the possibility of these lesions representing metastatic lesions is discussed.