Update on the classification and nomenclature system for neck dissection: revisions proposed by the Japan Neck Dissection Study Group.

BACKGROUND: Terminology for neck dissection is quite complicated because a large number of nonradical neck dissections were created by different surgeons, each of whom named their operational method in their own words in an attempt to preserve functions that were usually lost by radical neck dissection. This complication is still causing serious confusion among head and neck surgeons throughout the world, although there have been many proposals for standardization.
METHODS: Japan Neck Dissection Study Group created in 2005 and updated in 2009 a new classification and nomenclature system that is easy to understand, compatible with Japanese classifications of other carcinomas, and easily interchangeable with other neck dissection terminology proposals.
RESULTS: Based on the Classification of Regional Lymph Nodes in Japan, published by the Japan Society of Clinical Oncology, our new system divides cervical lymph nodes into four basic regions and other regions. Each of the four basic regions is further divided into several subregions. Each region, subregion, or principal nonlymphatic structure has its own symbol consisting of one alphabetical letter, two alphabetical letters, or one alphabetical letter plus one numeral. Each neck dissection operation is designated by a combination of these symbols. Neck dissections are classified into two groups, total neck dissection and selective neck dissection, according to the extent of resection of the cervical lymph nodes.
CONCLUSION: We simply hope that this new system will contribute to resolving the confusion over the terminology used for neck dissection, not only in Japan but throughout the world.