Congenital midline sinus of the upper lip.

A congenital lip sinus is a rare condition that has been reported to occur in both the upper and lower lips, either in isolation or in association with congenital deformities such as a cleft lip and palate in Van der Woude syndrome. The prevalence of lower lip sinuses has been estimated to be about 0.00001% of the white population. Upper lip sinuses are even more uncommon. To date, there have been several case reports of upper lip sinuses and fistulas, but no similar cases have been described in Singapore. We herein report a case of congenital upper lip sinus presenting as a recurring upper lip abscess and review the current literature on this condition.