A preauricular sinus or cyst (also known as a "Congenital auricular fistula," "Congenital preauricular fistula," "Ear pit":782, and "Preauricular cyst" ) is a common congenital malformation characterized by a nodule, dent or dimple located anywhere adjacent to the external ear. They are inherited features and usually appear on one side, but may be bilateral in 25-50% of cases. Preauricular sinuses and cysts result from developmental defects of the first and second branchial arches. Occasionally a preauricular sinus or a cyst can become infected. This and other congenital ear malformations are associated with renal anomalies.
Most preauricular sinuses are asymptomatic and remain untreated unless they become infected too often. Preauricular cysts are treated with surgery which, because of their close proximity to the facial nerve should be left to an experienced surgeon, such as an otolaryngologist - head and neck surgeon.