Primary Adenoid Cystic Carcinoma of the Frontal Sinus: Case Description of a Previously Unreported Entity and Literature Review.

Sinonasal adenoid cystic carcinoma is a rare malignant epithelial tumor characterized by slow growth, multiple local recurrences, and perineural invasion; surgery followed by radiotherapy provides the best overall survival by means of an endoscopic, craniofacial, or combined approach. We present a previously undescribed case of frontal sinus adenoid cystic carcinoma involving the subcutaneous tissue and the dura mater treated with an open technique, free flap reconstruction, and hadron therapy together with a summary of the state of the art.