Lymph Node Groups
IA |
- Between anterior belly of the digastric and hyoid |
IB |
- Between anterior and posterior bellies of the digastric, the stylohyoid, and the body of the mandible. |
IIa & IIB |
- Upper third of IJ from the skull base (above) to the inferior border of the hyoid (below); lateral border of the sternohyoid and the stylohyoid (medial) to the posterior border of the SCM (lateral).* |
III |
- Middle third of IJ from the inferior border of the hyoid bone (above) to the inferior border of the cricoid cartilage (below); lateral border of the sternohyoid (medial) to the posterior border of the SCM (lateral).* |
IVA & IVB |
- Lower third of IJ from the inferior border of the cricoid cartilage (above) to the clavicle (below); lateral border of the sternohyoid (medial) to the posterior border of the SCM (lateral).* - IVA is separated from IVB by the deep surface of the sternocleidomastoid muscle |
VA & VB |
- Along lower half of CN XI and the transverse cervical artery. From the convergence of the SCM and trapezius (above) to the clavicle (below); the posterior border of the (medial),* to the anterior border of the trapezius (lateral). |
VI |
- Between the hyoid bone (above) to the suprasternal notch (below), and the common carotid arteries. |
VII |
- Top of manubrium (above) to innominate vein (below); between common carotid arteries laterally |
* The surgical landmark that defines the lateral boundary of Levels II, III, and IV and the corresponding medial boundary of the posterior triangle (Level V) is the plane that parallels the sensory branches of the cervical plexus.
References
Grégoire V, Ang K, Budach W, Grau C, Hamoir M, Langendijk JA, Lee A, Le QT, Maingon P, Nutting C, O'Sullivan B, Porceddu SV, Lengele B. Delineation of the neck node levels for head and neck tumors: a 2013 update. DAHANCA, EORTC, HKNPCSG, NCIC CTG, NCRI, RTOG, TROG consensus guidelines. Radiother Oncol. 2014 Jan;110(1):172-81. doi: 10.1016/j.radonc.2013.10.010. Epub 2013 Oct 31. PMID: 24183870.
Pagedar NA, Hoffman HT. Anatomic Variability of the Accessory Nerve: Implications for Dissection of Level IIB. Laryngoscope. 2024 Jan;134(1):154-159. doi: 10.1002/lary.30758. Epub 2023 Jun 8. PMID: 37289066; PMCID: PMC10703995.
Iwanaga J, Lofton C, He P, Dumont AS, Tubbs RS. Lymphatic System of the Head and Neck. J Craniofac Surg. 2021 Jul-Aug 01;32(5):1901-1905. doi: 10.1097/SCS.0000000000007230. PMID: 33201067.