Hi I am Dr Fahim, General Surgeon I welcome you to Healthcare magic and I will be looking into your query . . . I have gone through your question and understood your concerns. It appears to be sebaceous cyst, if its on the scrotal sac. The second differential diagnosis may be Epididymal Cyst, if it is in the apex of scrotum, in the epididymis. The sebaceous cyst may stays there for years with minimal changes and can gets painful when it gets infected. Then it must be surgical removed with antibiotics cover. While Epididymal cyst is a benign cystic accumulation of sperm that arises from the head of the epididymis. In majority case only observation is needed, as it’s asymptomatic disease. Surgical intervention; which is excision of the cyst, is indicated for painful and enlarging Epididymal Cyst. I hope my answer will help you. Do rate it, if you like it Regards