Radiographic studies of a 42-year-old woman reveal that she has a vulvar malignancy involving the clitoris. Removal of all affected lymph nodes would be indicated to avoid spread of this cancer. Which are the first lymph nodes to filter the lymphatic drainage of the involved area?

The deep inguinal lymph nodes drain the glans clitoris and receive lymph also from superficial nodes. The internal iliac nodes drain the inferior pelvic structures, deep perineal structures, and sacral nodes. The paraaortic lymph nodes, or lumbar nodes, receive lymph from the common iliac nodes. The drainage of presacral lymph nodes can pass to the common or internal iliac nodes. Axillary nodes drain body wall structures above the T10 dermatome (or the umbilicus).