Learning Objectives

By the end of this article, you should be able to:

Describe the functions of the lymphatic system in the upper limb
Distinguish between superficial and deep lymphatic vessels and their drainage patterns
Identify the five groups of axillary lymph nodes and their clinical significance
Apply anatomical knowledge to clinical conditions such as axillary lymphadenopathy and lymphoedema

The lymphatic system plays a vital role in maintaining tissue fluid balance and immune defence. It drains excess interstitial fluid, plasma proteins, and cellular debris from tissues and returns them to the venous circulation.

Once interstitial fluid enters lymphatic vessels, it is termed lymph. This lymph is filtered through lymph nodes, where immune surveillance occurs, before being returned to the bloodstream via the venous system.

In this article, we will examine the lymphatic drainage of the upper limb, focusing on the lymphatic vessels, axillary lymph nodes, and their clinical correlations.

Lymphatic Vessels of the Upper Limb

Superficial Lymphatic Vessels

The superficial lymphatic vessels arise from lymphatic plexuses in the skin of the hand, formed by networks of lymphatic capillaries within the extracellular spaces. These vessels ascend the upper limb in close association with the major superficial veins.

Vessels accompanying the basilic vein enter the cubital lymph nodes, located medial to the vein and proximal to the medial epicondyle of the humerus. Efferent vessels from these nodes ascend the arm and drain into the lateral (humeral) axillary lymph nodes.
Vessels accompanying the cephalic vein typically cross the proximal arm and shoulder to drain directly into the apical axillary lymph nodes. In some individuals, these vessels instead terminate in the deltopectoral lymph nodes.

Deep Lymphatic Vessels

The deep lymphatic vessels accompany the major deep veins of the upper limb, including the radial, ulnar, and brachial veins. They drain lymph from deeper structures, such as:

Muscles
Tendons
Periosteum
Joint capsules

These vessels terminate primarily in the humeral (lateral) axillary lymph nodes, with occasional additional lymph nodes located along their course.

Axillary Lymph Nodes

Most lymph nodes of the upper limb are located within the axilla and are anatomically divided into five groups:

1. Pectoral (Anterior) Nodes

3–5 nodes
Located along the medial wall of the axilla
Drain lymph from the anterior thoracic wall, including most of the breast

2. Subscapular (Posterior) Nodes

6–7 nodes
Located along the posterior axillary fold
Drain lymph from the posterior thoracic wall and scapular region

3. Humeral (Lateral) Nodes

4–6 nodes
Located along the lateral wall of the axilla, posterior to the axillary vein
Receive most lymph from the upper limb

4. Central Nodes

3–4 large nodes
Situated near the base of the axilla, deep to the pectoralis minor
Receive efferent vessels from the pectoral, subscapular, and humeral nodes

5. Apical Nodes

Located at the apex of the axilla near the axillary vein and the first part of the axillary artery
Receive lymph from the central nodes and lymphatic vessels accompanying the cephalic vein

Efferent vessels from the apical nodes pass through the cervico-axillary canal to form the subclavian lymphatic trunk:

On the right, this drains into the right lymphatic duct
On the left, it drains into the thoracic duct

Clinical Relevance

Axillary Lymphadenopathy

Axillary lymphadenopathy refers to enlargement of axillary lymph nodes and commonly occurs due to:

Infections of the upper limb, resulting in lymphangitis
- The humeral nodes are typically affected first
- Red, warm, tender streaks may be visible along the limb
Breast and pectoral region infections
Metastatic spread of breast carcinoma

Axillary Lymph Node Dissection

Axillary lymph node dissection is an important procedure in breast cancer staging. However, disruption of lymphatic drainage from the upper limb can lead to lymphoedema, characterised by painful and persistent swelling of the limb.

Potential complications include injury to: