Approximately 300 lymph nodes are located in the head and neck, and they comprise 30% of the total 800 lymph nodes in the human body. In 1880, Kocher and Uber reported the detrimental effect of neck metastasis in patients with head and neck cancer. In 1906, George Washington Crile reported his experience with 132 neck dissections in JAMA: The Journal of the American Medical Association. The advent of functional neck dissections, aimed at reducing morbidity and maintaining function, was made possible with the further advancement of understanding of the lymphatic spread in the 1960s.
Cervical metastasis has a tremendous impact on the prognosis in patients with carcinomas of the head and neck. The presence of neck metastasis is known to reduce survival by 50%, and the frequency of such spread is greater than 20% for most squamous cell carcinomas (SCCAs). The presence of extra capsular spread further halves the chances of cure. Predictive factors of cervical metastasis are primary site, primary tumor size, degree of differentiation of tumor, perineural invasion, perivascular invasion, inflammatory response, and tumor DNA content (ploidy).
Advantages of modified neck dissection (MND) over radical neck dissection (RND) are preservation of neck and shoulder functions, better cosmetic results, protection of the internal carotid artery (ICA), and availability of simultaneous bilateral surgeries.
MND offers the same survival rate and disease-free survival benefits as classic RND.