The appearance of the supraclavicular fossa (SCF) is quite variable and the presence of a radiographically visible fossa (Fig. 1) depends upon the patient’s body habitus and weight,
as well as the position of the shoulders.
The depth of the fossa is extremely variable.
The SCF is most likely to be present in thin patients or with the shoulders elevated.
Normal Anatomy:
The SCF is a superiorly concave space located at the base of the neck,
immediately above and posterior to the clavicle,
being a subdivision of the posterior triangle of the neck (Fig. 2 and Fig. 3).
The medial wall of the SCF is continuous with the skin over the lateral aspect of the sternocleidomastoid muscle.
The SCF ends laterally at the attachment of the trapezius muscle to the distal clavicle.
It is limited anteromedially by the sternocleidomastoid muscle,
posteromedially by the trapezius muscle and superiorly by the omohyoid muscle.
Its pavement is formed by the middle scalene muscle and the first fasciculation of the anterior serratus muscle,
involved by the deep layer of the deep cervical fascia.
Its roof is formed by skin,
superficial fascia and platysma muscle.
Its content includes a series of structures that intersect this region,
separated from each other by connective and adipose tissue,
such as: the subclavian,
suprascapular and transverse cervical arteries and veins; the terminal portions of internal and external jugular veins; lymph nodes (LN); the thoracic duct on the left side; the lymphatic duct on the right side; the brachial plexus trunk; the phrenic nerve; and scalene muscles (Fig. 4).
The supraclavicular lymph nodes,
although not contemplated in the known seven-level classifications of cervical LN,
participate in the lymphatic drainage of the neck.
In addition,
because of their adjacent location to the confluence of the thoracic and lymphatic ducts into the venous system,
the supraclavicular LN also drain the lymph from the thoracic and abdominal-pelvic cavities.
Consequently,
several malignant tumors can metastasize to these LN,
most frequently to the left side (Virchow node).
The enlargement of the Virchow node may be manifested by the presence of a palpable mass in the SCF on the clinical examination,
known as Troisier's signal.
For being crossed by multiple structures,
the SCF may be the site of manifestation of a panoply of pathologies.
In fact,
LN metastasis from tracheobronchial tree,
gastrointestinal and genitourinary system tumors are the most commonly detected focal lesions in the SCF.