3. Neck: diseases, injuries, inflammations and tumors

ANATOMICAL FRAMEWORK

• The neck contains the airway, pharynx, oesophagus, thyroid, parathyroids, salivary tissue, cervical vessels, lymphatic chains, nerves and cervical spine.
• The sternocleidomastoid divides the neck into anterior and posterior triangles.
• The carotid sheath contains the common/internal carotid artery, internal jugular vein and vagus nerve.
• The deep cervical fascia creates potential spaces through which infection can spread to the mediastinum.
• The thyroid lies anterior to the trachea; recurrent laryngeal nerves run near the tracheoesophageal grooves and the external branch of the superior laryngeal nerve is close to the superior thyroid pedicle.

CLASSIFICATION OF NECK SWELLINGS

• Use age, site, duration and consistency.
• Causes include congenital lesions (thyroglossal duct cyst, branchial cleft cyst, cystic hygroma), inflammatory/infective nodes, tuberculosis, salivary disease, thyroid enlargement, benign tumours, primary malignancy and metastatic cervical lymphadenopathy.
• In adults, a persistent unexplained neck mass must be considered malignant until adequately evaluated.
• Midline lesions suggest thyroid or thyroglossal pathology; lateral lesions include lymph nodes, branchial lesions and salivary or vascular masses.