Levels | Nodes | Boundaries | |||
---|---|---|---|---|---|
 |  | Superior | Inferior | Anterior (medial) | Posterior (lateral) |
IA Submental group | Submental nodes | Symphysis of mandible | Body of hyoid | Anterior belly of contralateral digastric muscle | Anterior belly of ipsilateral digastric muscle |
IB Submandibular group | Submandibular nodes | Body of mandible | Posterior belly of digastric muscle | Anterior belly of digastric muscle | Stylohyoid muscle |
IIA Upper Jugular group Nodes | Nodes around upper portions of Internal jugular vein and Accessory Nerve | Skull base | Horizontal plane defined by the inferior border of hyoid bone | Stylohyoid muscle | Vertical plane defined by the spinal accessory nerve |
IIB Upper Jugular group Nodes | Â | Skull base | Horizontal plane defined by the inferior border of hyoid bone | Vertical plane defined by the spinal accessory nerve | Lateral border of the sternocleidomastoid muscle |
III Mid Jugular group | Nodes around mid portions of Internal jugular vein | Horizontal plane defined by the inferior border of hyoid bone | Horizontal plane defined by the inferior border of cricoid cartilage | Lateral border of the sternohyoid muscle | Lateral border of the sternocleidomastoid muscle or sensory branches of the cervical plexus |
IV Lower Jugular group | Nodes around lower third of IJV | Horizontal plane defined by the inferior border of cricoid cartilage | Clavicle | Lateral border of the sternohyoid muscle | Lateral border of the sternocleidomastoid muscle or sensory branches of the cervical plexus |
VA Posterior triangle group | Nodes around lower part of Accessory nerve and transverse cervical vessels | Apex of the convergence of sternocleidomastoid and trapezius muscles | Horizontal plane defined by the inferior border of cricoid cartilage | Lateral border of the sternocleidomastoid muscle or sensory branches of the cervical plexus | Anterior border of the trapezius muscle |
VB Posterior triangle group | Â | Horizontal plane defined by the inferior border of cricoid cartilage | Clavicle | Lateral border of the sternocleidomastoid muscle or sensory branches of the cervical plexus | Anterior border of the trapezius muscle |
VI Central or anterior group | Nodes surrounding midline visceral structures of neck | Hyoid bone | Suprasternal | Common carotid artery | Common carotid artery |