Nasofrontal dermoid cyst: rare presentation of a philtrum sinus.

Congenital midline nasal lesions are extremely rare, and nasal dermoids are their most common presentation. To the best of our knowledge, only two cases of a philtrum sinus with skull base extension have been reported previously. A 3-year-old boy presented to the maxillofacial department with a discharging upper lip sinus that had been present from birth. No other congenital abnormalities were reported. Initially this sinus was assumed to be blind-ended and excised under general anaesthetic, but the area then failed to heal. Radiological work-up showed a patent dermal sinus that extended from the infranasal region through the nasal septum into the basal aspect of the anterior cranial fossa. The patient was referred for multidisciplinary management. A high index of suspicion of nasofrontal dermoid should be exercised when a patient presents with an upper lip sinus and recurrent discharge, until it is proven otherwise.