A 32-year-old man visits the outpatient clinic and says he has had a painless mass at his right scrotum for several months. Ultrasonographic examination reveals a homogeneous hypoechoic intratesticular mass. Biopsy reveals a seminoma. Cancer of the testis metastasizes first to which of the following lymph nodes?

Lymph vessels from the testicles follow the path of the testicular blood supply (abdominal aorta), and therefore lymph from the testicles drains into the lumbar nodes. The superficial inguinal lymph nodes drain lymph from the lower limb. The deep inguinal nodes drain lymph from the superficial inguinal nodes, the glans of the penis, and spongy urethra. The external iliac nodes drain lymph from anterosuperior pelvic structures and receive lymph from the deep inguinal nodes. Internal iliac nodes drain lymph from inferior pelvic structures and receive lymph from the sacral nodes.