Preauricular sinus is an occasional finding and most frequently appears as a small pit close to the anterior margin of the ascending portion of the helix. The opening has also been reported along the postero superior margin of the helix, the tragus or the lobule. Preauricular sinus may lead to the formation of a subcutaneous cyst that is intimately related to the tragal cartilage and the anterior crus of the helix. [from
HPO]