The lymph node structures are characterized by a certain anatomical regularity and the clinician must have a clear arrangement of the different local-regional chains. At the neck level, the following groupings can be distinguished: anterior, submandibular and submentonary cervical lymph nodes, superficial and deep cervical lymph nodes.
The anterior cervical lymph nodes have, in fact, a greater degree of variability and can be divided into two further subgroups, superficial and deep. Those in the first group are arranged irregularly along the course of the anterior jugular vein. The deep ones, on the other hand, can be further divided into four small chains: paratracheal of the tracheoesophageal sulcus, infraioidea (superficial to the thyroid membrane), pretracheal (between the deep cervical fascia and the trachea) and prelaringea, resting on the cricothyroid ligament.
The submandibular and submental lymph nodes form a sort of second defensive ring to be placed side by side with the well-known Waldeyer ring, a set of structures of lymphoid tissue associated with the mucous membrane (mucose-associated lymphoid tissue MALT) that surrounds the coannins and isthmus of the jaws.
These lymph node structures are responsible for the drainage of the tongue and oral cavity. In this area, there are also two real glandular structures, namely the major salivary glands called submandibular and sublingual. To provide a clinical note, this site is normally approached with bimanual technique (extra and simultaneously intraoral) and follows the general criteria of lymph node diagnosis: in most cases, the swelling is reactive in response to inflammatory-infectious processes affecting the oropharynx, while malignancy is an uncommon occurrence.
The submandibular group occupies a triangular space near the homonymous gland. The chain consists of three to six lymph nodes, of which the most constantly present is located on the outer face of the mandibular body, closely associated with the facial artery.
The submental triangle, on the other hand, is delimited on two sides on three by the front bellies of the two digastric muscles.
The superficial cervical lymph nodes are flanked by the external jugular vein in the stretch where it runs superficially to the sternocleidomastoid muscle.
The numerous lymph nodes of the deep cervical group form a chain along the carotid sheath. They play a particularly important role as they drain the entire head-neck compartment. The relative lymphatic vessels are tributaries of the jugular trunk, which in turn drains into the right lymphatic duct or directly into the left thoracic duct, connecting from there to the circulatory system.
The topographical distinction is between deep cervical lymph nodes at the top, a wide chain surrounding the internal jugular vein, extending from the mastoid process to the upper edge of the subclavian triangle, and at the bottom, sites substantially corresponding to the same subclavian triangle.