Topic Overview

Lymphatic Drainage of the Breast

Importance

• Most important clinically because breast carcinoma spreads via lymphatics.

• Careful understanding is essential for surgery (mastectomy, axillary clearance).

Lymphatic Drainage of the Parenchyma

1. Axillary Group (≈ 75%)

• Drains mainly lateral and upper parts of breast (especially upper outer quadrant and axillary tail).

• Pathway:

  • First to anterior (pectoral) group of axillary nodes.

  • Then to central nodes → apical nodes → subclavian trunk → venous angle.

• Clinical: explains why axillary node involvement is common in breast cancer.

2. Parasternal Group (Internal Mammary Nodes)

• Drains medial quadrants of breast.

• Nodes along internal thoracic (mammary) vessels.

• Communicate with opposite side → explains spread of carcinoma to contralateral breast.

3. Posterior Intercostal Nodes

• Drains deep part of breast (especially posterior region).

• Nodes along posterior intercostal vessels.

• Communicate with vertebral venous plexus → explains vertebral metastasis.

4. Subdiaphragmatic and Subperitoneal Plexus

• Drains inferior part of breast.

• Communicates with liver → explains frequent hepatic metastasis.

Lymphatic Drainage of the Skin of the Breast

• Except areola and nipple: drains into axillary, internal thoracic, and intercostal nodes.

• Areola and nipple: drained by a special subareolar plexus of Sappey, which communicates widely with parenchymal lymphatics.

Clinical Relevance

• Carcinoma of breast spreads mainly to axillary nodes → early axillary dissection in surgery.

• Peau d’orange: obstruction of cutaneous lymphatics → skin appears pitted like orange peel.

• Nipple retraction: fibrosis and lymphatic blockage around lactiferous ducts.

• Contralateral spread: due to communication via parasternal nodes.

• Vertebral metastasis: via posterior intercostal nodes and vertebral venous plexus.