If it has been there from 7 to 8 years it is likely to be a tumour like a lipoma. Or it maybe a cyst like sebaceous cyst. These are the commonest causes. There might be many other causes as well. A high frequency ultrasound scan will be able to differentiate if it is a solid mass or a cystic mass and give some other information about the lump. Most likely it will require surgery. Please get it diagnosed either by a general surgeon or a dermatologist. Once diagnosed you can plan the treatment. Warm regards. Dr. Rajdeep Mysore. Chirag Hospital Bangalore