The pelvic lymph nodes are clustered around similarly named arteries (with some exceptions as always).
External Iliac Lymph Nodes
These nodes are found along the external iliac vessels, in the lateral parts of the pelvis. They drain lymph from:
- The leg and buttocks, via superficial and deep inguinal nodes
- The superior aspect of the bladder
- Rarely, the prostate
- In women, the superior parts of the uterus
External iliac nodes drain to common iliac nodes.
Internal Iliac Lymph Nodes
These nodes are found along the internal iliac vessels (and its branches). An important cluster is known as the obturator nodes. These are found, occasionally, along the obturator artery as it makes its way forward to the obturator foramen. This group of nodes is rarely mentioned in anatomy texts but is of importance for oncology.
Internal iliac nodes drain lymph from:
- All pelvic structures, although they are not the only route of drainage
- The deep parts of the buttock may drain via the gluteal vessels to internal iliac nodes
- The upper part of the anal canal drains to internal iliac nodes
Internal iliac nodes drain to common iliac nodes.
Presacral nodes
The presacral nodes are found in the mesorectum. They drain lymph from:
- The rectum and anal canal
- The prostate
- In women, the cervix, uterus and upper part of the vagina
Presacral nodes may drain to common iliac nodes, lumbar nodes, or inferior mesenteric nodes.
Common Iliac Nodes
These nodes are found along the common iliac vessels. They drain lymph from the other pelvic nodal groups.
Lumbar nodes
While not strictly 'pelvic', these nodes (also known as para-aortic or para-caval nodes) lie around the aorta and inferior vena cava. They drain lymph from the lower body via the common iliac nodes. They also receive lymph from the gonads, the uterine tubes and occasionally from the uterus in women.
