A 32 yeаr оld security оfficer cоmes to your clinic, complаining of а firm, painless mass in his scrotum. He found it 3 days ago during a testicular self exam. Palpation of his scrotum shows a soft cystic like lesion measuring 2 cm over his right testicle. It transilluminates upon exam. There is no difficulty getting a gloved finger through either inguinal ring. With weight bearing there are no bulges. His prostate exam is unremarkable. What disorder of the scrotum does he most likely have?