Cervical lymph nodes
Cervical lymph nodes are lymph nodes found in the neck. Of the 800 lymph nodes in the human body, 300 are in the neck. Cervical lymph nodes are subject to a number of different pathological conditions including tumours, infection and inflammation. There are approximately 300 lymph nodes in the neck, and they can be classified in a number of different ways. The classification of the cervical lymph nodes is generally attributed to Henri Rouvière in his 1932 publication "Anatomie des Lymphatiques de l'Homme" Rouviere described the cervical lymph nodes as a collar which surrounded the upper aerodigestive tract, consisting of submental, facial, submandibular, parotid, mastoid, occipital and retropharyngeal nodes, together with two chains that run in the long axis of the neck, the anterior cervical and postero-lateral cervical groups. However, this system was based upon anatomical landmarks found in dissection, making it imperfectly suited to the needs of clinicians, which led to new terminology for the lymph nodes that could be palpated. The most commonly used system is one based on a classification of the lymph nodes into numbered groupings, devised at the Memorial Sloan Kettering Cancer Center in the 1930s. This has been variously modified since. In 1991, the American Academy of Otolaryngology published a standardised version of thisto provide a uniform approach to neck dissection that was updated in 2002, including the addition of sub-levels, e.g. IIA and IIB. More recently, classification systems have been proposed organized around what can be observed via diagnostic imaging. In addition to the American Academy of Otolaryngology, systems have been devised by the American Joint Committee on Cancer (AJCC). The AJCC system from the 7th edition of the Staging Manual (2009) remains unchanged in the 8th edition of 2018. The American Academy of Otolaryngology system (2002) divides the nodes as follows: Level I: Submental and submandibular nodes Level Ia: Submental - within the triangular boundary of the anterior belly digastric muscles and the hyoid bone.
