A 46-year-old man has a swelling in the scrotum. It shows clear transillumination anterior to the testis when a light is applied to the scrotum in a dark room. This physical exam is most consistent with?: (A) Cyst of the epididymis, (B) Torsion of testis, (C) Hydrocele, (D) Direct inguinal hernia
Answer is C. In adults, this is diagnostic, but in children, transillumination is also seen in an indirect inguinal hernia. As epididymal cyst may transilluminate but is posterior to the testis.