lymph node
A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that inclu ...
s found in the
neck
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 ...
. 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
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
,
infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dise ...
and
inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...
.
Classification
There are approximately 300 lymph nodes in the neck, and they can be classified in a number of different ways.
History
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
Memorial Sloan Kettering Cancer Center (MSK or MSKCC) is a cancer treatment and research institution in the borough of Manhattan in New York City, founded in 1884 as the New York Cancer Hospital. MSKCC is one of 52 National Cancer Institute– ...
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
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 ...
that was updated in 2002, including the addition of sub-levels, e.g. IIA and IIB.
Modern systems
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 {{Short description, Organization standardising cancer staging
The American Joint Committee on Cancer (AJCC) is an organization best known for defining and popularizing cancer staging standards, officially the AJCC staging system.
The American Joi ...
(AJCC). The AJCC system from the 7th edition of the Staging Manual (2009) remains unchanged in the 8th edition of 2018.
Lymph node levels
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
The digastric muscle (also digastricus) (named ''digastric'' as it has two 'bellies') is a small muscle located under the jaw. The term "digastric muscle" refers to this specific muscle. However, other muscles that have two separate muscle belli ...
and the
hyoid
The hyoid bone (lingual bone or tongue-bone) () is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies between the base of the mandible and the third cervical vertebra. ...
bone.
** Level Ib:
Submandibular triangle
The submandibular triangle (or submaxillary or digastric triangle) corresponds to the region of the neck immediately beneath the body of the mandible.
Boundaries and coverings
It is bounded:
* ''above'', by the lower border of the body of the man ...
- within the boundaries of the anterior belly of the digastric muscle, the
stylohyoid muscle
The stylohyoid muscle is a slender muscle, lying anterior and superior of the posterior belly of the digastric muscle. It is one of the suprahyoid muscles. It shares this muscle's innervation by the facial nerve, and functions to draw the h ...
and the body of the
mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...
.
* Level II:
Upper jugular nodes
The deep cervical lymph nodes are a group of cervical lymph nodes found near the internal jugular vein in the neck.
Structure
The deep cervical lymph nodes can be divided into upper and lower groups, or superior and inferior groups.
Alternati ...
(Subdigastric nodes) - around the upper third of the
internal jugular vein
The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and neck. This vein runs in the carotid sheath with the common carotid artery and vagus nerve.
It begins in the posteri ...
and adjacent
accessory nerve
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 nerv ...
. The upper boundary is the
base of the skull
The base of skull, also known as the cranial base or the cranial floor, is the most inferior area of the skull. It is composed of the endocranium and the lower parts of the calvaria.
Structure
Structures found at the base of the skull are for ...
and the lower boundary is the inferior border of the hyoid bone. The anterior/medial boundary is the
stylohyoid muscle
The stylohyoid muscle is a slender muscle, lying anterior and superior of the posterior belly of the digastric muscle. It is one of the suprahyoid muscles. It shares this muscle's innervation by the facial nerve, and functions to draw the h ...
and the posterior/lateral one is the posterior border of the
sternocleidomastoid muscle
The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and flexion of the neck. The sternocleidomastoid is innervated by the access ...
. On imaging the anterior/medial boundary is the vertical plane of the posterior surface of the
submandibular gland
The paired submandibular glands (historically known as submaxillary glands) are major salivary glands located beneath the floor of the mouth. They each weigh about 15 grams and contribute some 60–67% of unstimulated saliva secretion; on stimula ...
.
** Level IIa: Anterio-medial to the vertical plane of the accessory nerve.
** Level IIb: Postero-lateral to this plane.
* Level III:
Middle jugular nodes
The deep cervical lymph nodes are a group of cervical lymph nodes found near the internal jugular vein in the neck.
Structure
The deep cervical lymph nodes can be divided into upper and lower groups, or superior and inferior groups.
Alternati ...
- around the middle third of the internal jugular vein, from the inferior border of the hyoid to the inferior border of the
cricoid cartilage
The cricoid cartilage , or simply cricoid (from the Greek ''krikoeides'' meaning "ring-shaped") or cricoid ring, is the only complete ring of cartilage around the trachea. It forms the back part of the voice box and functions as an attachment si ...
. Antero-medially they are bounded by the lateral border of the
sternohyoid muscle
The sternohyoid muscle is a thin, narrow muscle attaching the hyoid bone to the sternum. It is one of the paired strap muscles of the infrahyoid muscles. It is supplied by the ansa cervicalis. It depresses the hyoid bone.
Structure
The sternohy ...
and postero-laterally by the posterior border of the sternocleidomastoid.
* Level IV:
Lower jugular nodes
The deep cervical lymph nodes are a group of cervical lymph nodes found near the internal jugular vein in the neck.
Structure
The deep cervical lymph nodes can be divided into upper and lower groups, or superior and inferior groups.
Alternati ...
- around the lower third of the internal jugular vein from the inferior border of the cricoid to the
clavicle
The clavicle, or collarbone, is a slender, S-shaped long bone approximately 6 inches (15 cm) long that serves as a strut between the shoulder blade and the sternum (breastbone). There are two clavicles, one on the left and one on the rig ...
, anteromedially by the lateral border of the sternohyoid and posterolaterally by the posterior border of the sternocleidomastoid.
* Level V: Posterior triangle nodes - around the lower half of the spinal accessory nerve and the
transverse cervical artery
The transverse cervical artery (transverse artery of neck or transversa colli artery) is an artery in the neck and a branch of the thyrocervical trunk, running at a higher level than the suprascapular artery.
Structure
It passes transversely b ...
, and includes the supraclavicular nodes. The upper boundary is the apex formed by the convergence of the sternocleidomastoid and
trapezius muscle
The trapezius is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula. It moves the scapula and supports the ...
s, and inferiorly by the clavicle. The anteromedial border is the posterior border of the sternocleidomastoid and the posterolateral border is the anterior border of the trapezius.
** Level VA: Above the horizontal plane formed by the inferior border of the
anterior cricoid arch
The cricoid cartilage , or simply cricoid (from the Greek ''krikoeides'' meaning "ring-shaped") or cricoid ring, is the only complete ring of cartilage around the Vertebrate trachea, trachea. It forms the back part of the larynx, voice box and fun ...
, including the spinal accessory nodes.
** Level VB: Lymph nodes below this plane, including the transverse cervical nodes and supraclavicular nodes (except
Virchow's node
Supraclavicular lymph nodes are lymph nodes found above the clavicle, that can be felt in the supraclavicular fossa. The supraclavicular lymph nodes on the left side are called Virchow's nodes.Pretracheal, paratracheal, precricoid (Delphian) and perithyroid nodes, including those on the
recurrent laryngeal nerve
The recurrent laryngeal nerve (RLN) is a branch of the vagus nerve (cranial nerve X) that supplies all the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles. There are two recurrent laryngeal nerves, right and le ...
. The upper border is the hyoid, the lower the
suprasternal notch
The suprasternal notch, also known as the fossa jugularis sternalis, jugular notch, or Plender gap, is a large, visible dip in between the neck in humans, between the clavicles, and above the manubrium of the sternum.
Structure
The suprasternal ...
, and the lateral borders the
common carotid arteries
In anatomy, the left and right common carotid arteries (carotids) (Entry "carotid" in mediastinal
The mediastinum (from ) is the central compartment of the thoracic cavity. Surrounded by loose connective tissue, it is an undelineated region that contains a group of structures within the thorax, namely the heart and its vessels, the esophagu ...
rather than cervical nodes, and therefore should not be included in the classification of neck nodes. However it is based on the 2002 American Academy system, although the boundaries are defined slightly differently.
The boundaries are defined as (Superior, Inferior, Antero-medial, Postero-lateral)
* Level IA: Symphysis of mandible, Body of hyoid, Anterior belly of contralateral digastric muscle, Anterior belly of ipsilateral digastric muscle
* Level IB: Body of mandible, Posterior belly of digastric muscle, Anterior belly of digastric muscle, Stylohyoid muscle
* Level IIA: Skull base, Horizontal plane defined by the inferior border of the hyoid bone, The stylohyoid muscle, Vertical plane defined by the spinal accessory nerve
* Level IIB: Skull base, Horizontal plane defined by the inferior body of the hyoid bone, Vertical plane defined by the spinal accessory nerve, Lateral border of the sternocleidomastoid muscle
* Level III: Horizontal plane defined by the inferior body of hyoid, Horizontal plane defined by the inferior border of the cricoid cartilage, Lateral border of the sternohyoid muscle, Lateral border of the sternocleidomastoid or sensory branches of
cervical plexus
The cervical plexus is a plexus of the anterior rami of the first four cervical spinal nerves which arise from C1 to C4 cervical segment in the neck. They are located laterally to the transverse processes between prevertebral muscles from the medi ...
* Level IV: Horizontal plane defined by the inferior border of the cricoid cartilage, Clavicle, Lateral border of the sternohyoid muscle, Lateral border of the sternocleidomastoid or sensory branches of cervical plexus
* Level VA: Apex of the convergence of the sternocleidomastoid and trapezius muscles, Horizontal plane defined by the lower border of the cricoid cartilage, Posterior border of the sternocleidomastoid muscle or sensory branches of cervical plexus, Anterior border of the trapezius muscle
* Level VB: Horizontal plane defined by the lower border of the cricoid cartilage, Clavicle, Posterior border of the sternocleidomastoid muscle, Anterior border of the trapezius muscle
* Level VI: Hyoid bone, Suprasternal notch, Common carotid artery, Common carotid artery
* Level VII: Suprasternal notch,
Innominate artery
The brachiocephalic artery (or brachiocephalic trunk or innominate artery) is an artery of the mediastinum that supplies blood to the right arm and the head and neck.
It is the first branch of the aortic arch. Soon after it emerges, the brachio ...
,
Sternum
The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Sh ...
,
Trachea
The trachea, also known as the windpipe, is a Cartilage, cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends ...
,
esophagus
The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the ...
, and
prevertebral fascia
The prevertebral fascia (or prevertebral layer of cervical fascia) is a fascia in the neck.
Variations
In some literature, the prevertebral fascia also includes the other fascial layers extending around the vertebral column and enclosing all musc ...
While an imaging based system was proposed in 1999, these concepts were integrated into the 2002 revision of the American Academy system. In addition to needing a standardised approach to classification of lymph nodes for the purposes of neck dissection, the application of
radiation therapy
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radia ...
also requires such an approach and has resulted in an international consensus guideline (2013).
Clinical significance
Infectious mononucleosis
Infectious mononucleosis (IM, mono), also known as glandular fever, is an infection usually caused by the Epstein–Barr virus (EBV). Most people are infected by the virus as children, when the disease produces few or no symptoms. In young adult ...
''(glandular fever)'' affects the cervical lymph nodes which become swollen. The characterization of
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
MRI
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...
or
ultrasound
Ultrasound is sound waves with frequency, frequencies higher than the upper audible limit of human hearing range, hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hea ...
is difficult, and usually requires confirmation by other
nuclear imaging
Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is "radiology done inside out" because it records radiation emittin ...
techniques such as
PET scan
Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, r ...
s. Tissue diagnosis by
fine needle aspiration
Fine-needle aspiration (FNA) is a diagnostic procedure used to investigate lumps or masses. In this technique, a thin (23–25 gauge (0.52 to 0.64 mm outer diameter)), hollow needle is inserted into the mass for sampling of cells that, aft ...
(which has a high rate of accuracy), may also be required. Involvement of the cervical lymph nodes with
metastatic
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...
cancer is the single most important prognostic factor in
head and neck
This article describes the anatomy of the head and neck of the human body, including the brain, bones, muscles, blood vessels, nerves, glands, nose, mouth, teeth, tongue, and throat.
Structure Bones
The head rests on the top part of the vertebra ...
squamous cell carcinoma
Squamous-cell carcinomas (SCCs), also known as epidermoid carcinomas, comprise a number of different types of cancer that begin in squamous cells. These cells form on the surface of the skin, on the lining of hollow organs in the body, and on the ...
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
Papillary thyroid cancer or papillary thyroid carcinoma is the most common type of thyroid cancer, representing 75 percent to 85 percent of all thyroid cancer cases.Chapter 20 in: 8th edition. It occurs more frequently in women and presents in th ...
.
Additional images
File:Gray603.png, Lymphatics of pharynx.
File:Gray604.png, The lymphatics of the face.