Lymph Nodes

Level I nodes are found below the mandible and anterior to the submandibular glands. These nodes are divided into Level 1a and Level 1b. Level 1a nodes are midline in between the anterior belly of the digastric muscles. Level 1b are in between the anterior belly of the digastric and the submandibular gland.

Level II nodes are upper jugular chain nodes. They are nodes along the jugular chain above the hyoid bone, posterior to the submandibular gland, and anterior to the sternocleidomastoid muscle. Level IIa nodes are anterior to the jugular vein or posterior and touching the jugular vein . Level IIb nodes are posterior to the jugular vein and not touching the jugular vein. The border between level II and V is the sternocleidomastoid muscle. The border between level II and level III is the hyoid.

Level III nodes are middle jugular chain nodes. They are nodes along the jugular chain in between the hydoid and cricoid. The border between level III and level IV is the cricoid. The border between level III and level V is the posterior margin of the sternocleidomastoid muscle.

Level IV nodes are low jugular chain nodes. These are nodes along the jugular chain below the cricoid. The border between level IV and level VI is the common carotid artery. The border between level IV and level V is the sternocleidomastoid muscle.

Level V nodes are posterior triangle nodes. These nodes are posterior to the sternocleidomastoid muscle and anterior to the trapezius muscle. Level Va are upper posterior triangle nodes. The border between level Va and level IIb is the sternocleidomastoid muscle. The border between level Va and level Vb is the cricoid.

Level V nodes are posterior triangle nodes. These nodes are posterior to the sternocleidomastoid muscle and anterior to the trapezius muscle. Level Vb are lower posterior triangle nodes. The border between level Va and level IV is the sternocleidomastoid muscle. The border between level Va and level Vb is the cricoid.

Level VI nodes are central compartment/visceral nodes. These are nodes adjacent to the thyroid gland. The border between level I and Level VI is the hyoid. The border between level IV and level VI is the common carotid artery.

Retropharyngeal nodes are located behind the phayrnx. Lateral RP nodes are located anterior and medial to the cervical internal carotid artery.