Hi! Good evening. I am Dr Shareef answering your query. From such a long duration history, it seems to be a benign lesion like a sebaceous or dermoid cyst which has now got infected giving rise to the pain and increase in size for the last three days. However, it can be confirmed only by physical examination by your treating doctor. If I were your doctor, after physically examining you I would prescribe a course of antibiotics for you along with an anti inflammatory drug to contain the infective process. Once tha infection subsides, I would refer you to a general surgeon for a excision biopsy of the lesion, which could either be curative or diagnostic. I hope this information would help you in discussing with your family physician/treating doctor in further management of your problem. Please do not hesitate to ask in case of any further doubts. Thanks for choosing health care magic to clear doubts on your health problems. Wishing you an early recovery. Dr Shareef.