Hi Thanks for posting on HCM Lymphocele of the penis is a harmless, self-limiting condition that is commonly seen in sexually active males. It is cord like swelling seen on the shaft of penis usually after vigorous sex or masturbation.On the other hand, herpes may appear as a blister and may not have any relationship with sex or masturbation.Common symptoms of herpes may include blisters with the following properties: Pain or itching, Small red bumps or tiny white blisters, Ulcers. In your case, penile lymphocele is a more likely cause.I will suggest you just maintain a good genital hygiene and avoid avoid further sexual stimulation for some time.You may not need any special treatment for it. Hope this will help Wish you good health