Overview
Lymphatic drainage from the
head and neck travels either via paired superficial or deep cervical nodes and
vessels on either side of the neck. Ultimately, all lymph courses into a deep
chain where it drains into the venous system at the base of the internal
jugular vein.
Gross Anatomy
A horizontal band of nodes encircles
the craniocervical junction
Submental; in the midline below the chin. Drains
anterior lower oral cavity
Submandibular; in submandibular triangle. Drains remainder
of oral cavity, cheek, nose, forehead and anterior half of nasal cavity &
sinuses
Deep & superficial pre-auricular; lie deep and superficial to parotid. Drain
middle scalp, pinna and parotid gland
Post-auricular; lie
over the mastoid process. Drain pinna and posterior scalp
Occipital;
located at the apex of the posterior triangle. Drain the posterior scalp
· The deep cervical chain closely accompanies the
internal jugular vein through its course, deep to sternocleidomastoid.
Jugulodigastric;
drains upper pharynx and palatine tonsils
Jugulo-omohyoid;
drains posterior half of nasal cavity and sinuses, and hard & soft palates
Retropharyngeal;
drains pharynx
Paratracheal;
drains larynx, trachea, thryroid & parathyroids
· Superficial cervical chains accompany the
external and anterior jugular veins, between them receiving lymphatic drainage
from the whole antero-lateral cervical skin
· Both the circular nodal chain and the
superficial cervical chain drain into the deep cervical chain, where efferent
lymph vessels form the jugular lymphatic trunk
This drains into the thoracic
duct on the left or a common lymphatic trunk on the right.
These then drain lymph into
the brachiocephalic vein at the junction of the subclavian vein and the
internal jugular
Clinical Anatomy
·
Knowledge of which structures drain to
which groups of lymph nodes is important for determining the metastatic spread
of head and neck cancers
· Retropharyngeal nodes sit posterior to the pharynx; when enlarged they bulge anteriorly (due to pre-vertebral fascia posteriorly) putting pressure on the pharynx, causing dysphagia
· A modified radical neck dissection
involves removing all Level I – V nodes, whilst attempting to preserve as much
as possible of sternocleidomastoid, the internal jugular vein and Accessory
nerve (CN XI)
Quick Anatomy
Key Facts
Quick-look
box – Cervical lymphatic levels |
|
Level
I |
Submental & submandibular nodes |
Level
II |
Between base of the skull & the hyoid
bone |
Level
III |
Between the hyoid bone & cricoid
cartilage |
Level
IV |
Between cricoid cartilage & the clavicle |
Level
V |
Nodes in the posterior triangle |
Level
VI |
Nodes surrounding midline viscera |
Level
VII |
Nodes in the superior mediastinum |
Aide-Memoire
Summary
All lymphatic drainage from
the head and neck passes into the deep cervical nodes, either directly or
indirectly via the superficial nodes before draining into the subclavian vein.
Superficial structures drain superficially and deep structures deep. Lymph
nodes can be classified into levels in the context of treating malignancy.