Lymph node levels of the neck

Lymph nodes in the neck have been historically divided into seven levels based upon surgical anatomy, generally for the purpose of squamous cell carcinoma staging. The TNM atlas has since expanded upon this initial classification, however, it also has some deficiencies ⁹. The most comprehensive radiologic definitions have been established in the context of radiotherapy planning ⁸. 

Level I: submental and submandibular

• below mylohyoid muscle and above the lower margin of the hyoid bone (or the carotid bifurcation)
• anterior to the posterior border of the submandibular glands
  • level Ia: submental nodes, i.e. between the anterior bellies of the digastric muscles
  • level Ib: submandibular nodes, i.e. posterolateral to the anterior belly of the digastric muscles and anterior to the posterior border of the submandibular glands

Level II: upper internal jugular (deep cervical) chain

• base of the skull to the inferior border of hyoid bone (or the carotid bifurcation)
• anterior to the posterior border of sternocleidomastoid (SCM) muscle
• posterior to the posterior border of the submandibular glands
  • level IIa: inseparable from or anterior to the posterior edge of the internal jugular vein
    • most superior node is the jugulodigastric node
  • level IIb: posterior to the internal jugular vein and have a fat plane separating the nodes and the vein

Level III: middle internal jugular (deep cervical) chain

• inferior margin of hyoid to inferior margin of cricoid cartilage (or the intermediate tendon of omohyoid)
• anterior to the posterior border of SCM
• lateral to the medial margin of the common carotid artery (CCA) / internal carotid artery (ICA)

Level IV: lower internal jugular (deep cervical) chain

• inferior margin of cricoid cartilage to level of the clavicle
• anterior and medial to an oblique line drawn through the posterior edge of SCM and the posterolateral edge of the anterior scalene muscle ⁴
• lateral to the medial margin of the CCA

Level V: posterior triangle (spinal accessory)

• posterior to the posterior edge of the sternocleidomastoid muscle and anterior to the anterior border of the trapezius muscle 
  • level Va: superior half, posterior to levels II and III (between base of the skull and inferior border of cricoid cartilage)
  • level Vb: inferior half, posterior to level IV (between the inferior border of cricoid cartilage and the level of clavicles)

Level VI: anterior compartment, prelaryngeal, pre- and paratracheal

• from the inferior margin of hyoid bone to the manubrium
• anterior to levels III and IV
• includes the Delphian node and nodes in the visceral space

Level VII: (anterior) superior mediastinal

• from suprasternal notch to innominate artery
• technically outside the neck but still considered regional lymph nodes.

Additional neck levels

The above classification is not inclusive of several important groups, such as the supraclavicular, parotid, retropharyngeal space, and occipital nodes.

Other classification systems include these regions however a consensus approach has not been reached.  For example, the TNM atlas defines "region 7" as "supraclavicular nodes" ⁹, while radiation oncologists may consider "level VII" as "prevertebral nodes" ⁸.  These multiple definitions can lead to confusion and thus it is best to be descriptive with lymph nodes outside of the established levels I-VII.

See also

• cervical lymph node staging