Thanks for your question. It seems there is nothing to worry in your case because the swelling is not paining. This is usually seen in men of your age. But it should be investigated about. This can be due to a hydrocele, cyst, hernia, injury, infection, torsion etc. As your sonogram result shows that there is a fluid deposit in your testis, it might be a hydrocele. This occurs when fluid gets collected in testicular walls. This can be due to many reasons such as trauma, allergies or infections. This is a harmless issue and so, usually doesn’t require treatment. If it is enlarging, you can surgically release the fluid by incision or draw the fluid out by aspiration.