Hi,
Welcome to the forum. I am really glad to help you out. It is very difficult to comment without a physical examination. However, the possibilities which one can think of are an epididymal cyst/testicular tumor/cysts of morgagni.
The confirmation can be done by a surgical examination and an ultrasound of the testes. Please do consult a urologist for the same. The treatment will depend upon the underlying diagnosis. I sincerely hope that helps. Take care