Hi, Thanks for writing in. It is important to do a clinical examination and follow it up with an ultrasound scan of testis. The surgeon is the doctor who deals with testis related problems. Most swellings in and around the testis are benign and it looks like your tumor like growth is from the epididymis which is a structure at the head of the testis. There is usually no pain associated with cancer, though it might be felt by some patients. The growth also is hard and therefore requires detailed evaluation. It is possible that you had a benign cyst which might have got infected. Cancer in the testis is more common in the elderly but is also less often seen in young males. The ultrasound scan testis is most important and I guess you should get it done immediately. Please do not worry.