Lymphatic drainage of the superficial tissues of the head and neck: Anatomical study and clinical implications

BACKGROUND: Current knowledge of the anatomy of the lymphatic system does not match or explain some of the unexpected clinical and lymphoscintigraphic findings seen in head and neck cancer patients. There is the need, therefore, to remap the lymphatic network of the superficial tissues of the head and neck region. METHODS: Eighteen halves of the superficial tissues of the head and neck from nine fresh human cadavers were studied over a 20-month period using a mixture of 6% hydrogen peroxide (Orion Laboratories, Balcatta, Australia) with and without India ink to detect the lymphatic vessels and then inject them with a radiopaque lead oxide mixture (AJAX Chemicals, Sydney, Australia). RESULTS: These unique studies showed (1) lymph capillaries arising from the skin and the galea layers draining sequentially into precollecting lymph vessels, collecting lymphatics, and the first-tier lymph nodes; (2) collecting vessels averaging 0.2 mm in diameter with unusual "lymphatic ampullae" structures and inactive lymph nodes observed often along their course; (3) different network patterns between subjects and between sides of the same subject; (4) similar relationships between lymphatic and venous systems; (5) a lymphaticovenous shunt in the occipital region; (6) lymphatics sometimes bypassing the expected nodes to reach sentinel nodes in the root of the neck; and (7) the lymphatics of the anterior neck lying above the platysma and coursing horizontally, obliquely, and upward toward the mandible. CONCLUSION: A map of the head and neck lymphatics is presented to aid clinicians with the management of trauma and malignancies in the region.