Answer to Choose your Seat Wisely
Question: Metastasis from which labeled structure is most likely to drain to the iliac nodes?
Correct answer is D. In general, it is safe to assume that the lymphatic drainage of an organ, and hence metastasis from that organ, will follow the arterial supply, albeit in a retrograde direction. Hence, to answer this question correctly it becomes important to 1) identify the structure correctly, and 2) know its blood supply. The following Indicates this second point:
A.Lymph from the testes drain to the para-aortic nodes because their blood supply is provided by the gonadal arteries that branch directly from the abdominal aorta.
B.The superficial inguinal nodes drain the perineum/skin of the external genitalia.
C.The anal canal below the pectinate line drains to the superficial inguinal nodes.
D.The prostate drains to the iliac nodes. Also, the seminal vesicles, the ductus deferens, bladder and urethra drain to these nodes.
E.The glans penis drains to the deep inguinal nodes.
Testis
Perineum
Anal canal below pectinate line
Prostate
Glans penis
Answer to this question is based on material presented in lectures 3 of the Pelvis Lecture Series.
