Cervical lymph nodes | |
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Details | |
System | Lymphatic system |
Identifiers | |
Latin | nodi lymphoidei cervicales |
Anatomical terminology |
Cervical lymph nodes are lymph nodes found in the neck. Of the 800 lymph nodes in the human body, 300 are in the neck. [4] Cervical lymph nodes are subject to a number of different pathological conditions including tumours, infection and inflammation. [5]
There are approximately 300 lymph nodes in the neck, and they can be classified in a number of different ways. [4]
The classification of the cervical lymph nodes is generally attributed to Henri Rouvière in his 1932 publication "Anatomie des Lymphatiques de l'Homme" [6] [7] 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. [8]
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 this [9] to provide a uniform approach to neck dissection that was updated in 2002, including the addition of sub-levels, e.g. IIA and IIB. [2]
More recently, classification systems have been proposed organized around what can be observed via diagnostic imaging. [10] [8] [2] In addition to the American Academy of Otolaryngology, systems have been devised by the American Joint Committee on Cancer (AJCC). [10] The AJCC system from the 7th edition of the Staging Manual (2009) remains unchanged in the 8th edition of 2018. [11]
The American Academy of Otolaryngology system (2002) divides the nodes as follows: [1] [2] [3]
The American Joint Committee on Cancer (AJCC) system differs from the above by including Level VII, but the American Academy considered these to be anatomically mediastinal rather than cervical nodes, and therefore should not be included in the classification of neck nodes. [8] However it is based on the 2002 American Academy system, although the boundaries are defined slightly differently. [12]
The boundaries are defined as (Superior, Inferior, Antero-medial, Postero-lateral)
While an imaging based system was proposed in 1999, [10] these concepts were integrated into the 2002 revision of the American Academy system. [2] In addition to needing a standardised approach to classification of lymph nodes for the purposes of neck dissection, the application of radiation therapy also requires such an approach and has resulted in an international consensus guideline (2013). [13]
Infectious mononucleosis (glandular fever) affects the cervical lymph nodes which become swollen. The characterization of cancerous lymph nodes on CT scan, MRI or ultrasound is difficult, and usually requires confirmation by other nuclear imaging techniques such as PET scans. Tissue diagnosis by fine needle aspiration (which has a high rate of accuracy), may also be required. Involvement of the cervical lymph nodes with metastatic cancer is the single most important prognostic factor in head and neck squamous cell carcinoma and may be associated with a halving of survival. Where the cancer has penetrated the capsule of the lymph gland (extracapsular extension) survival may be decreased by a further 50%. Other important factors are the level, the number of nodes and their size, which are also correlated with the risk of distant metastases. Cervical lymph node metastasis is also a common feature of papillary thyroid carcinoma. [14] [15]
The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In addition, the neck is highly flexible and allows the head to turn and flex in all directions. The structures of the human neck are anatomically grouped into four compartments: vertebral, visceral and two vascular compartments. Within these compartments, the neck houses the cervical vertebrae and cervical part of the spinal cord, upper parts of the respiratory and digestive tracts, endocrine glands, nerves, arteries and veins. Muscles of the neck are described separately from the compartments. They bound the neck triangles.
The accessory nerve, also known as the eleventh cranial nerve, cranial nerve XI, or simply CN XI, is a cranial nerve that supplies the sternocleidomastoid and trapezius muscles. It is classified as the eleventh of twelve pairs of cranial nerves because part of it was formerly believed to originate in the brain. The sternocleidomastoid muscle tilts and rotates the head, whereas the trapezius muscle, connecting to the scapula, acts to shrug the shoulder.
In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplies blood to the right arm, with some branches supplying the head and thorax. On the left side of the body, the subclavian comes directly off the aortic arch, while on the right side it arises from the relatively short brachiocephalic artery when it bifurcates into the subclavian and the right common carotid artery.
The internal carotid artery is an artery in the neck which supplies the anterior and middle cerebral circulation.
The omohyoid muscle is a muscle in the neck. It is one of the infrahyoid muscles. It consists of two bellies separated by an intermediate tendon. Its inferior belly is attached to the scapula; its superior belly is attached to the hyoid bone. Its intermediate tendon is anchored to the clavicle and first rib by a fascial sling. The omohyoid is innervated by the ansa cervicalis of the cervical plexus. It acts to depress the hyoid bone.
The neck dissection is a surgical procedure for control of neck lymph node metastasis from squamous cell carcinoma (SCC) of the head and neck. The aim of the procedure is to remove lymph nodes from one side of the neck into which cancer cells may have migrated. Metastasis of squamous cell carcinoma into the lymph nodes of the neck reduce survival and is the most important factor in the spread of the disease. The metastases may originate from SCC of the upper aerodigestive tract, including the oral cavity, tongue, nasopharynx, oropharynx, hypopharynx, and larynx, as well as the thyroid, parotid and posterior scalp.
The stylohyoid muscle is one of the suprahyoid muscles. Its originates from the styloid process of the temporal bone; it inserts onto hyoid bone. It is innervated by a branch of the facial nerve. It acts draw the hyoid bone upwards and backwards.
In anatomy, the left and right common carotid arteries (carotids) are arteries that supply the head and neck with oxygenated blood; they divide in the neck to form the external and internal carotid arteries.
The sternohyoid muscle is a bilaterally paired, long, thin, narrow strap muscle of the anterior neck. It is one of the infrahyoid muscles. It is innervated by the ansa cervicalis. It acts to depress the hyoid bone.
The carotid sheath is a condensation of the deep cervical fascia enveloping multiple vital neurovascular structures of the neck, including the common and internal carotid arteries, the internal jugular vein, the vagus nerve, and ansa cervicalis. The carotid sheath helps protects the structures contained therein.
The occipital artery is a branch of the external carotid artery that provides arterial supply to the back of the scalp, sternocleidomastoid muscles, and deep muscles of the back and neck.
The posterior triangle is a region of the neck.
The superior thyroid artery arises from the external carotid artery just below the level of the greater cornu of the hyoid bone and ends in the thyroid gland.
The deep cervical fascia lies under cover of the platysma, and invests the muscles of the neck; it also forms sheaths for the carotid vessels, and for the structures situated in front of the vertebral column. Its attachment to the hyoid bone prevents the formation of a dewlap.
The carotid triangle is a portion of the anterior triangle of the neck.
The inferior carotid triangle, is bounded, in front, by the median line of the neck from the hyoid bone to the sternum; behind, by the anterior margin of the sternocleidomastoid; above, by the superior belly of the omohyoid.
The superior deep cervical lymph nodes are the deep cervical lymph nodes that are situated adjacent to the superior portion of the internal jugular vein. They drain either to the inferior deep cervical lymph nodes or into the jugular trunk.
The submental lymph nodes are 2-3 lymph nodes situated in the submental triangle, between the anterior bellies of the digastric muscle and the hyoid bone.
The following outline is provided as an overview of and topical guide to human anatomy:
The parapharyngeal space, is a potential space in the head and the neck. It has clinical importance in otolaryngology due to parapharyngeal space tumours and parapharyngeal abscess developing in this area. It is also a key anatomic landmark for localizing disease processes in the surrounding spaces of the neck; the direction of its displacement indirectly reflects the site of origin for masses or infection in adjacent areas, and consequently their appropriate differential diagnosis.