By Dr. Sachin Sudhakaran and Dr. Maddie Swannack
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Due to the large number of structures in the neck, the differentials for neck lumps can be very varied. This article gives an overview of the possible causes of neck lumps and the key features to ask about when assessing a neck lump in primary care.
To make it easier, this article is split into two parts. The first is a summary of the things that can cause a midline neck lump, that is to say a lump in the centre of the anterior neck. The second is a summary of the things that can cause a lump that is more lateral, so any lump that does not fall in the centre of the anterior neck.
A cervical (neck) dermoid cyst is a benign developmental inclusion cyst, formed when skin-forming tissue is trapped during embryological fusion (the joining together of parts of the embryo). It may present as a painless lump in the midline, particularly beneath the chin in the submental region. Its wall contains skin structures such as hair follicles and sweat glands, and its contents may include keratin (the tough protein in skin and hair), sebum (the oily skin secretion) and hair. A true dermoid is distinguished histologically from a teratoid cyst, which contains derivatives of all three embryonic germ layers (the three layers of cells that form the embryo). Teeth are not typical contents of a cervical dermoid; a true dermoid is a skin-containing inclusion lesion rather than a cystic teratoma (a tumour that can contain several tissue types, including hair and teeth). Unlike a thyroglossal duct cyst, a dermoid cyst is tethered (stuck) to the skin.
A thyroglossal duct cyst is a congenital sac filled with fluid that forms in the midline of the neck. When the thyroid forms, it descends from the base of the tongue into the neck, leaving a path called the thyroglossal duct. Normally the duct closes up completely (obliterates), but in some people it can remain patent (open), creating cavities that can fill with fluid.
The cysts are generally painless, and will move superiorly with protrusion of the tongue and on swallowing (because the tongue and the thyroid are connected with this patent duct). If the fluid in the cyst becomes infected, the cyst may become painful.
Standard treatment of thyroglossal duct cysts is surgical removal of the cyst and the entire thyroglossal duct. To reduce recurrence, this usually involves removal of the central portion of the hyoid bone (the small U-shaped bone in the midline of the neck, just above the thyroid cartilage) along with the cyst and duct.
Pathology of the Thyroid Gland
The thyroid gland sits on the anterior trachea, just below the thyroid cartilage (‘Adam’s Apple’). This means that a swelling of the thyroid gland (a goitre) can often be seen on the anterior neck, although small ones may not be visible. A thyroid swelling will move upwards on swallowing as the thyroid is connected to the trachea.
Swellings of the thyroid can be benign (for example as a result of an autoimmune condition like Graves’ disease, a cause of an overactive thyroid) or malignant (cancers such as papillary, follicular, medullary or anaplastic carcinoma). Most thyroid nodules (discrete lumps within the thyroid) are benign.
Lymph nodes are an important part of the lymphatic system and act as a physical and phagocytic (germ-engulfing) filter. There are two classifications of lymph node in the neck.
Superficial Cervical Lymph Nodes
Superficial cervical lymph nodes are found within the superficial cervical fascia (a layer of connective tissue just under the skin). Lymph from the face and scalp ultimately drains into these nodes, so a swollen node (lymphadenopathy) points to a cause in the area it drains (e.g. submental lymphadenopathy should prompt examination of the oral cavity).
Key superficial cervical lymph nodes
- Submental
- Submandibular
- Pre-auricular (in front of the ear)
- Post-auricular (behind the ear)
- Occipital (back of the head)
- Superficial Cervical
- Posterior Cervical
- Anterior Cervical
Diagram - Location of superficial lymph nodes on the left side of the head and neck
Creative commons source by Olek Remesz, edited by Dr. Sachin Sudhakaran [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]
Deep cervical lymph nodes are located deep to the superficial cervical fascia. They are closely associated with the internal jugular vein and can be found within the carotid sheath (the connective tissue tube around the carotid artery, jugular vein and vagus nerve). Most superficial lymph nodes of the neck drain into these lymph nodes, and structures such as the thyroid and palatine tonsils (the tonsils on either side of the back of the throat) drain directly into deep cervical lymph nodes. These lymph nodes are not usually palpable unless they are significantly enlarged.
Key deep cervical lymph nodes:
- Jugulo-digastric (named after the jugular vein and the digastric muscle)
- Jugulo-omohyoid (named after the jugular vein and the omohyoid muscle)
- Supraclavicular (above the collarbone) Lymph Nodes
Diagram - Location of deep lymph nodes on the left side of the neck. Note that the supraclavicular nodes are usually found deep within the supraclavicular fossa
Creative commons source by Olek Remesz, edited by Dr. Sachin Sudhakaran [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]
Lymphadenopathy, or the swelling of lymph nodes, can occur for a number of reasons.
Lymph nodes can become swollen due to malignancy. This can be primary malignancy of the lymphatic system, such as lymphoma, or secondary malignancy causing swelling as cancer originating in another organ spreads to the lymphatic system.
One notable example of malignancy spreading to the lymph nodes in the neck is the left supraclavicular node, named Virchow’s Node, which is a sign of cancer that has spread from another part of the body. It is classically linked to cancer in the abdominal cavity, such as the stomach and the rest of the upper gut, but it can also come from the lung, the thyroid or from the urinary and reproductive organs (for example the ovaries, testicles and kidneys). These cancers can remain asymptomatic (cause no symptoms) while spreading (metastasising), so it is important to examine the left supraclavicular fossa (the hollow above the left collarbone) for enlarged nodes.
Lymphadenopathy can also occur as a reaction to infection or inflammation. Swelling of this kind is known as reactive lymphadenopathy. Reactive lymph nodes are often tender when examined, but tenderness cannot be relied on to rule out cancer.
The salivary glands that cause neck lumps are the submandibular (antero-inferior to the angle of the mandible) or the parotid (the largest salivary gland, posterior to the angle of the mandible) glands. This means that any neck lumps caused by salivary glands are very lateral in their positioning.
Pathology of the salivary glands that can cause neck lumps includes calculi (stones), infection, benign tumours or malignancy. Stones typically cause swelling and tenderness that get worse when the person is eating, and acute infection causes rapid-onset pain and swelling. Benign tumours (nearly 80% of salivary gland tumours are benign) are usually painless, slow-growing and mobile. Malignant tumours are rare and typically come with features such as pain, rapid growth, skin fixation (the lump is stuck to the skin) or facial nerve involvement.
A branchial cyst is a congenital cyst forming along the anterior border of the sternocleidomastoid muscle (the large neck muscle running from the breastbone and collarbone up to the bone behind the ear), typically at the junction of its upper one-third and lower two-thirds.
Branchial cysts originate from the incomplete obliteration (closing up) of the branchial clefts (also called pharyngeal clefts), which are key features in the embryological formation of structures in the head and neck. Most arise from the second cleft. Normally, the clefts close up completely, but in some cases a small gap is left, which can form a collection of fluid. Although normally painless, this fluid can become infected, making the lump painful.
Pathology of the Carotid Arteries
The carotid arteries are also a key structure in the neck. Pathology of the carotid arteries can include aneurysms (abnormal bulges in the artery wall) or tumours (paragangliomas, rare tumours that grow beside the carotid artery). Both lie along the course of the carotid artery and usually pulsate. Auscultation (listening with a stethoscope) over the lump may reveal a bruit (a whooshing sound caused by turbulent blood flow).
There are numerous causes for neck lumps, spanning from recent or concurrent infection to underlying malignancy. To add another level of complexity, neck lumps may not be associated with lymph nodes at all. When presented with a neck lump, it’s important to perform a thorough history and examination.
Factors to explore in the history:
- Age
- Duration
- Progression (e.g. change in size, texture, temperature).
- Consider associated symptoms - e.g. sore throat, change in voice, difficulty breathing, difficulty swallowing.
- Explore red flag symptoms (see below)
Key features on examination:
- General inspection - e.g. scars, hoarseness of voice, exophthalmos (bulging eyes).
- Location - is it in the midline, or in the anterior or posterior triangle of the neck (the areas in front of and behind the sternocleidomastoid muscle)?
- If midline:
- Ask the patient to swallow some water to assess movement of the mass (movement upwards during swallowing is suggestive of a thyroid mass, due to the thyroid’s attachment to the trachea, but a thyroglossal duct cyst also moves upwards on swallowing).
- Ask the patient to protrude their tongue (with thyroglossal duct cysts, the lump moves upwards).
- Palpate and identify:
- Size
- Shape - are there identifiable borders?
- Consistency - is it hard, soft, smooth, irregular?
- Mobility - is it tethered (stuck) to surrounding tissue?
- Tenderness
- Overlying skin changes (e.g. erythema, which means redness)
Important Red Flags (features that raise the suspicion of cancer):
- Present for more than 6 weeks
- Hard and irregular texture
- Fixed/tethered to surrounding tissue
- Rapidly growing in size
- Associated fatigue, weight loss, night sweats
- Persistent hoarseness, or dysphagia (difficulty swallowing)
- Age 40 or over, especially with smoking or heavy alcohol use
A neck lump that is persistent and unexplained should prompt consideration of referral on a suspected cancer pathway (see the NICE guideline Suspected cancer: recognition and referral, NG12). Specialist referral should not be delayed while tests are arranged in primary care.
Neck lumps are commonly investigated with an ultrasound scan (USS). This shows the size, position and internal structure of the lump (for example whether it is solid or filled with fluid). If a lump is suspicious on USS, an ultrasound-guided fine needle aspiration (taking a sample of cells with a thin needle) is usually indicated. Fine needle aspiration can miss lymphoma, so a core needle biopsy (taking a small cylinder of tissue) may be needed when lymphoma is suspected. If the assessment suggests a possible serious cause, specialist referral should not be delayed while tests are arranged in primary care.
If further imaging is required, CT or MRI scans may be offered, especially if cancer is suspected or surgical management may be needed.
Reviewed by: Dr. Thomas Burnell and Dr. Marcus Judge
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