Hello,
For such kind of growths, the possibilities of epididymal cyst or spermatocele have to be ruled out. Spermatocele is a retention cyst of a tubule and is benign in nature. Usually they are left as such if not causing any symptom, but if they are causing pain, then they have to be removed. Surgery is the only mode of treatment for which I would suggest you to consult a urologist. The other possibilities are varicocele and testicular benign or malignant growths.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. Treatment can be started only when the diagnosis is confirmed. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
An ultrasound should be done.