A spermatocele is a fluid-filled cyst that develops in the epididymis, which is a small tube located at the back of each testicle. These cysts are usually benign and can vary in size. They often contain sperm and are generally painless, making them commonly discovered during routine examinations. While spermatoceles are not typically harmful, they can sometimes cause discomfort or swelling. Treatment is usually unnecessary unless the cyst becomes painful or bothersome, in which case a doctor may recommend surgical removal. Regular check-ups can help monitor any changes in size or symptoms.