Hello and thanks for your query. I shall make an effort to provide you with good professional recommendations specific to your questions. it is difficult to diagnose without examination, is there history of injury, if so that might be the cause and most often will subside. As you have not mentioned about injury, it is unlikely. Apart from this it may be dermoid or Sebaceous cyst, which can be diagnosed by examination, so i would suggest you to see surgeon for further help. Management depends on diagnosis. Yet again, I duly appreciate your query to me, I do hope that you have found something useful to help you and I shall be glad to answer any further apprehensions. Sincerely,