Triangles and Lymph node levels of Neck

There are 2 major triangles in the neck, containing other smaller triangles.

neck triangles
1 – parotid gland; 2 – submandibular gland; 3a – superior belly of omohyoid; 3b – inferior belly of omohyoid; 4 – sternohyoid; 5 – sternal head of SCM; 5b – clavicular head of SCM; 6 – EJV; 7 – greater auricular nerve

1. Anterior triangle: Midline of neck – Mandible – Anterior border of SCM

  • Submental triangle: IA (Submental LN)
  • Submandibular or Digastric triangle: IB (Submandibular LN), Submandibular gland, CN XII
  • Carotid triangle: II + III, Carotid sheath (CCA, IJV, XN X)
  • Muscular triangle: IV, Infrahyoid muscles, Thyroid and Parathyroid glands

Posterior triangle: Posterior border of SCM – Trapezius – Clavicle (level V); 2 triangles inside separated by inferior belly of omohyoid

  • Occipital triangle: OT GLASS
    • Occipital artery
    • Transverse cervical artery and vein
    • Greater auricular nerve (C2, C3)
    • Lesser occipital nerve (C2)
    • Accessory spinal nerve (CN XI)
    • Supraclavicular nerve (C3, C4)
    • Small muscular branches: Levator scapulae (C3, C4), Trapezius (C3, C4), Rhomboideus (C5)
  • Supraclavicular or Subclavian triangle:
    • 3 trunks of brachial plexus
    • Nerves arising from roots and trunks of brachial plexus:
      • Long thoracic nerve (C5, C6, C7) – serratus anterior
      • Nerve to subclavius (C5, C6)
      • Suprascapular nerve (C5, C6)
    • Subclavian artery (3rd part) and Subclavian vein
    • Suprascapular artery and vein
    • External jugular vein (lower part)
Lymph node levels of neck
Visual mnemonic or schematic diagram showing boundaries of lymph node levels or zones of neck

Surgically, cervical lymph nodes are divided into 6-7 levels (only 6 according to many authors who exclude the level VII nodes) for staging of carcinoma which would also be the basis for selective neck dissection. There are 5 levels in the lateral compartment and 2 in the central compartment. Nodes not included in these system of levels are retropharyngeal group, periparotid group, buccinator group, post auricular group and suboccipital group of nodes.

LevelLymph nodesBoundaries
IASubmental nodesBilaterally: Anterior belly of digastrics
Inferiorly: Hyoid bone
BSubmandibular nodesSuperiorly: Mandible
Posteroinferiorly: Posterior belly of digastrics
Anteroinferiorly: Anterior belly of digastrics
IIA (Anterior to the vertical line in relation to spinal accessory nerve)Upper internal jugular (deep cervical) nodesSuperiorly: Skull base
Inferiorly: Inferior border of hyoid bone and Carotid bifurcation
Posteriorly: Posterior border of Sternocleidomastoid (SCM)
Anteriorly: Lateral border of Sternohyoid and Stylohyoid
B (Posterior to the vertical line in relation to spinal accessory nerve)
IIIMid internal jugular (deep cervical) nodesSuperiorly: Inferior border of hyoid bone and Carotid bifurcation
Inferiorly: Inferior border of cricoid cartilage and Junction of omohyoid muscle and IJV
Posteriorly: Posterior border of SCM
Anteriorly: Lateral border of sternohyoid
IVLower internal jugular (deep cervical nodes)Superiorly: Inferior border of cricoids cartilage and Junction of omohyoid and IJV
Inferiorly: Clavicle
Posteriorly: Posterior border of SCM
Anteriorly: Lateral border of sternohyoid
VA (Above the horizontal plane marking the inferior border of arch of cricoids cartilage)Posterior triangle (spinal accessory) nodesSuperiorly: Convergence of SCM and trapezius
Inferiorly: Clavicle
Posteriorly: Anterior border of trapezius
Anteriorly: Posterior border of SCM
B (Below the horizontal plane marking the inferior border of arch of cricoids cartilage)
VI (Prelaryngeal or Delphian, Pretracheal, Paratracheal, Prethyroidal)Anterior compartment (midline) nodesSuperiorly: Hyoid bone
Inferiorly: Suprasternal notch
Bilaterally: Carotid arteries
VIIUpper mediastinal nodesBelow suprasternal notch

The highest jugular digastric node near the angle of the mandible is called the “sentinel” node.
The “signal” node is the lowest along the internal jugular chain called the virchow nodes.

Zones of neck

Probable source of Nodal metastasis:

  • Level 1: Oral cavity, submandibular gland
  • Level 2: Nasopharynx, oropharynx, parotid, supraglottic larynx
  • Level 3: Oropharynx, hypopharynx, supraglottic larynx
  • Level 4: Subglottic larynx, hypopharynx, esophagus, thyroid
  • Level 5: Nasopharynx, oropharynx
  • Level 6 & 7: Thyroid, larynx, lung
lymphatic drainage neck nodes level

Note: Bilateral nodes are common with cancers of soft palate, tongue, epiglottis, and nasopharynx.

Selective Neck dissection involves:

  • Supraomohyoid/Anterolateral: Level I to III
  • Extended Supraomohyoid: Level I to IV
  • Lateral: Level II to IV
  • Posterolateral: Level II to V
  • Anterior or Central: Level VI
  • Superior mediastinal: Level VII

Comprehensive Neck dissection inolves:

  • Radical and Modified Radical Neck Dissection: Level I to V

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