I welcome you to health care magic I am Dr Fahim, General Surgeon and I will be addressing your health concern I have gone through your question and understood your concerns. I appears to be lipoma, which is a collection of fat under the skin. Simple tests like it is mobile, skin can be pinched over it, helps in diagnosis. However you need to go to general surgeon, who after examination will establish his diagnosis. Treatment of this simple condition is excision under local anaesthesia. Other differential diagnosis can be sebaceous cyst, some muscular growth or hematoma etc. In difficult cases Ultrasonography of the lump can lead us to diagnoses. Wishing you all the best and rapid recovery. I hope my answer will help you. Do rate my answer if you like it. Regards