Intermediate external iliac nodes

At a glance

English

Intermediate external iliac nodes

Latin (TA2)

Nodi iliaci externi intermedii

System

Lymphatic

Region

Trunk

Side

Paired, left and right

About the intermediate external iliac nodes

The external iliac nodes run along the external iliac artery and vein from the pelvic brim to the inguinal ligament. They form three chains: a lateral chain on the outer side of the artery, a medial chain below and inside the vein, and an intermediate chain set back between the two vessels. This page covers the intermediate chain.

The intermediate nodes lie on the medial edge of psoas major and the side wall of the pelvis, partly hidden by the artery in front of them. At the lower end of the chain, near the inguinal ligament, a node often sits close to the femoral ring, linking this chain with the deep inguinal nodes in the femoral canal below.

Most of their lymph comes from the deep and superficial inguinal nodes, which drain the lower limb, the skin of the lower abdominal wall, the buttock and the perineum. They also receive vessels directly from the deep layers of the lower abdominal wall and from the bladder. After filtering, lymph passes upwards to the common iliac nodes.

This chain is a key station when a cancer of the lower limb or the bladder spreads, and it is routinely cleared in pelvic lymph node dissection. Swelling may also follow a spreading infection of the leg once the inguinal nodes have been passed. Removing many of these nodes can slow lymph return from the leg and cause lymphoedema.

Course and drainage

Begins at

Efferent vessels from the inguinal nodes, plus direct vessels from the deep lower abdominal wall and the bladder.

Drains into

Efferent vessels ascend to the common iliac nodes.

Drains

A relay for lymph from the lower limb, lower abdominal wall and bladder. The chain is examined and often removed when a bladder or lower limb cancer spreads, and its loss can lead to leg lymphoedema.