K) Lymph Nodes Of The Head and Neck
The lymph nodes of the head and neck are viewed as either anatomical groups or surgical lymph node regions.
Superficial Nodes of the Head
The superficial lymph nodes form a ring extending from the chin to the occiput.
From anterior to posterior, these are:
- Submental nodes are located inferior to the mandible, between the anterior bellies of the digastric muscles.
- The drain lymph from the anterior tongue, the medial inferior lip, the medial inferior gingivae and teeth, and the chin
- Efferent lymph vessels pass to the submandibular group or to deep cervical nodes
- Submandibular nodes are located deep to the body of the mandible, lateral to the anterior belly of digastric and typically in close proximity to the submandibular salivary gland
- They drain lymph from the lateral and superior lips, the cheek, the nose, the medial eyelid, and the submental nodes.
- Efferent vessels pass to superior deep cervical nodes
- Parotid nodes are located predominately within the superficial lobe of the parotid gland.
- They drain lymph from the lateral parts of the face, including the lateral eyelids, as well as from the anterior and lateral scalp.
- Efferent vessels follow the retromandibular vein and its divisions to either the superficial or the deep cervical nodal groups.
- Mastoid nodes are located posterior to the mastoid process and ear.
- They drain lymph from the lateral scalp
- Efferent vessels pass to superficial and deep cervical nodes
- Occipital nodes lie posteriorly, located over the insertion of trapezius into occipital bone.
- Lymph from the skin near the occiput drains to these nodes
- Efferent vessels pass to the deep cervical nodes, along the posterior border of sternocleidomastoid.
- Facial nodes are uncommonly found in the area of the cheek. They drain to submandibular or parotid nodes.
Superficial Nodes of the Neck
Anterior and posterior nodes drain the superficial parts of the head and neck. They anastamose with the deep system.
- Anterior Cervical nodes lie anterior to the pretracheal fascia within the anterior triangle of the neck.
- They are usually found in association with the anterior jugular vein
- They drain lymph from the skin of the anterior neck, below the hyoid bone
- Efferent vessels pass to deep nodes on either side of the neck
- Posterior cervical nodes are found in the posterior triangle
- These drain lymph from the lateral and posterior skin of the neck
- Efferent vessels pass to the transverse cervical (supraclavicular) nodal group
Deep Nodes of the Neck
The deep cervical nodes are the main pathway of drainage for the head and neck. Numerous other nodal groups are located throughout the neck.
- Deep cervical nodes surround the internal jugular vein, deep to sternocleidomastoid. They are divided into upper and lower groups.
- These nodes collect lymph from the other groups of the head and neck.
- Superior deep cervical nodes typically drain to inferior deep nodes.
- Efferent vessels from inferior deep cervical nodes typically collect into a single jugular trunk. This unites with the thoracic duct on the left prior to entering the brachiocephalic vein. On the right, the jugular trunk usually empties directly into the brachiocephalic vein.
- Retropharyngeal nodes are found in the retropharyngeal space between the pharynx and vertebral bodies. They drain lymph predominately from the pharynx, including the fauces.
- Paratracheal nodes lie between the trachea and oesophagus, accompanying the recurrent laryngeal nerve.
- Pretracheal, prelaryngeal and infrahyoid nodes lie beneath deep cervical fascia. They typically drain the anterior cervical nodes and empty into deep cervical nodes.
- Transverse cervical nodes are located above the clavicle, accompanying the transverse cervical vessels.
Surgical Lymph Node Stations
Head and neck cancers tend to involve certain lymph node groups, and surgical grouping of nodes is used when staging malignancies.
- Level I nodes include the submental (IA) and submandibular (IB) nodal groups. The anterior belly of the digastric muscle divides the two groups. The medial extent of Ib is marked by the stylohyoid muscle.
- Level II-IV nodes includes all deep cervical nodes. Level II extends from the skull base to the inferior border of the hyoid bone. Level III extends from level II to the inferior border of the cricoid cartilage. Level IV continues from level III to the clavicle.
- Level V nodes are located in the posterior triangle of the neck. Level Va, located above a line drawn posteriorly from the inferior border of the cricoid cartilage, contains the posterior cervical nodes. Level Vb, below that level, contains the transverse cervical nodes.
- Level VI nodes include the anterior cervical, paratracheal, pretracheal, and infrahyoid nodes. It extends from the hyoid bone superiorly to the sternal notch inferiorly. The lateral margins are the carotid arteries.
