Posterior axillary nodes

At a glance

English

Posterior axillary nodes

Latin (TA2)

Nodi axillares posteriores nodi subscapulares

System

Lymphatic

Region

Whole body

Side

Paired, left and right

About the posterior axillary nodes

The posterior axillary nodes, also called the subscapular nodes, lie on the back wall of the axilla. This wall is formed by subscapularis above and by teres major and latissimus dorsi below, and the nodes run along its lower margin where the posterior axillary fold can be felt. They follow the subscapular artery and vein and their continuation, the thoracodorsal vessels, which descend on the chest wall with the thoracodorsal nerve. The group usually contains six or seven nodes.

Each of the axillary groups faces a different territory, and this one faces backwards. Its position on the posterior wall matches the region it serves, the back of the trunk and shoulder.

Lymph reaches the posterior group from the skin and muscle of the lower nape, the posterior chest wall and the region over the scapula, down to about the level of the iliac crest on the back. Its efferent vessels pass to the central axillary nodes, and from there lymph continues to the apical nodes and the subclavian trunk.

These nodes may enlarge with infections and skin cancers of the upper back and shoulder, so a melanoma on the back is one reason to examine the posterior wall of the armpit. They can also be involved in breast cancer that has spread through the axilla. When they are removed, the surgeon must protect the thoracodorsal nerve and vessels that run beside them, since the nerve supplies latissimus dorsi.

Course and drainage

Begins at

Afferent vessels from the skin and muscle of the lower nape, the posterior chest wall and the scapular region.

Drains into

Efferent vessels pass to the central axillary nodes.

Drains

Filters lymph from the upper back and the back of the shoulder. Relevant to skin cancer of the back; clearing them puts the thoracodorsal nerve to latissimus dorsi at risk.