Principles of the Lymph Node Dissection in Non-melanoma Skin Cancer and Cutaneous Melanoma

Lymphadenectomy or lymph node dissection (LND) includes systematic dissection and biopsy of the regional lymph nodes. While LND is planned for staging purposes, it could also help with local control and systemic control of the cancers (prevention of other organs getting involved). The importance of the lymph node evaluation and surgical excision in the management of the cancers cannot be overemphasized. Due to its widespread list of possible early or late complications, LND is generally considered as a morbid procedure. Introduction of the sentinel lymph node biopsy (SLNB) in the last few years has been a wise attempt aiming in prevention of unnecessary morbidities associated with LND in the patients and at the same time trying to gain invaluable cancer staging data and even help in the local and systemic control of the cancers. Some of the consequences of these procedures (mostly LND but to a lesser degree SLNB) may take more than a decade to develop. Since its introduction, SLNB has been modified to help us in identification of the primary lymphatic drainage for skin and soft tissue malignancies. SLNB is supposed to give us regional information on cancerous lymph node involvement while avoiding the morbidity of the LND. The current chapter reviews the principles of the LND in simple terms with an overview of the lymph nodes regional anatomy. We will also discuss necessary preoperative evaluations, indications and the value of LND in the patients with different skin cancers, and possible complications of SLNB and LND.