Neck Lumps: A Structured Approach

Introduction

A neck lump is a common presenting complaint spanning an enormous range of underlying causes, from a self-limiting reactive lymph node to a metastatic malignancy. The single most useful organising principle is location: the neck is conventionally divided into anatomical triangles, and where a lump sits, together with the patient's age, points strongly towards the likely diagnosis before any investigation is done.¹

This article sets out that structured approach. Head and neck cancer and thyroid cancer, two of the more serious causes of a neck lump, are covered in full detail in their own articles.

Classification by anatomical location

A useful bedside discriminator for midline masses is movement with specific manoeuvres: a thyroid mass moves on swallowing (as it is attached to the pretracheal fascia), while a thyroglossal cyst moves on tongue protrusion (because of its embryological connection via the thyroglossal duct to the base of tongue) as well as on swallowing.^1,2

Lymphadenopathy

Enlarged cervical lymph nodes are the most common cause of a neck lump overall. The great majority are reactive, responding to a local or systemic infection - viral URTI, tonsillitis, dental infection, or infectious mononucleosis - and are typically soft, mobile and tender.¹

Malignant lymphadenopathy should be considered when a node is firm or hard, non-tender, fixed to surrounding structures, or progressively enlarging. This may represent lymphoma (classically rubbery, painless nodes, sometimes with systemic "B symptoms" - fever, night sweats, unintentional weight loss) or metastatic disease from a head and neck primary (usually squamous cell carcinoma) or, less commonly, from a primary below the clavicle.^1,3

Congenital and developmental neck lumps

These typically present in children, teenagers or young adults, often after becoming infected or otherwise brought to attention, though they are present from birth:^1,2

• Thyroglossal cyst: a midline cystic swelling arising from a remnant of the thyroglossal duct, moving on both swallowing and tongue protrusion; can become infected, and rarely harbours ectopic thyroid tissue or, very rarely, malignancy
• Branchial cyst: a lateral neck swelling in the upper anterior triangle, arising from incomplete obliteration of the second branchial cleft, typically presenting in the second or third decade, sometimes after an upper respiratory infection triggers enlargement or infection
• Cystic hygroma (lymphangioma): a soft, transilluminable, multiloculated swelling, usually in the posterior triangle, presenting in infancy and sometimes diagnosed antenatally
• Dermoid cyst: a midline swelling containing skin appendages, present from birth, not attached to deeper structures and does not move on swallowing or tongue protrusion

Other neck lumps

• Carotid body tumour (chemodectoma): a rare, slow-growing, pulsatile mass at the carotid bifurcation that is mobile side-to-side but not vertically ("Fontaine's sign"), and classically splays the internal and external carotid arteries on imaging
• Salivary gland pathology: sialadenitis, salivary stones (sialolithiasis, causing pain and swelling worse with eating), or a salivary gland tumour (a painless, slow-growing parotid or submandibular mass; new facial weakness with a parotid mass strongly suggests malignancy)
• Lipoma: a soft, mobile, non-tender subcutaneous swelling that can occur anywhere including the neck
• Thyroid nodules and goitre: covered in detail in the thyroid cancer article

Approach: history and examination

Key history points are duration and growth rate, pain, associated systemic ("B") symptoms, and features suggesting a head and neck primary - hoarseness, dysphagia, odynophagia, or referred otalgia. Ask about smoking, alcohol, recent infections, dental problems, travel (relevant to tuberculosis), and animal exposure (cat scratch disease).¹

On examination, assess site, size, consistency (soft, firm, hard, rubbery, or fluctuant), mobility or fixation, tenderness, and any overlying skin changes. Test for movement on swallowing and tongue protrusion for midline masses, and check for transillumination if a cystic hygroma is suspected. A full ENT examination - oral cavity, oropharynx, and flexible nasendoscopy - is essential whenever a head and neck primary is a possibility, alongside examination of other lymph node regions, the abdomen (for hepatosplenomegaly if lymphoma is suspected), and the thyroid.

Investigations

Ultrasound of the neck is the first-line investigation for almost any neck lump, distinguishing cystic from solid lesions and characterising features that raise or lower suspicion of malignancy, and can be combined with fine needle aspiration cytology of a solid or suspicious lesion.¹

If lymphoma is suspected, excision biopsy of a whole node (rather than FNA alone) is usually required, since full histological architecture is needed for accurate subtyping. Baseline bloods (FBC, inflammatory markers, EBV/Monospot testing, thyroid function where relevant) support the work-up, and a chest X-ray is useful when tuberculosis, lymphoma or sarcoidosis is being considered. CT or MRI of the neck further characterises deep or complex masses and stages any confirmed malignancy, and panendoscopy is used to search for an occult primary when metastatic squamous cell carcinoma is found in a neck node without an obvious source.

Management

Management depends entirely on the underlying cause. Reactive lymphadenopathy from a self-limiting infection is managed conservatively with review to confirm resolution. Congenital cysts (thyroglossal, branchial) are managed with elective surgical excision once any active infection has settled - a thyroglossal cyst requires the Sistrunk's procedure, removing the cyst together with its tract and the central portion of the hyoid bone, since leaving the tract behind gives a high recurrence rate.²

Lymphoma is managed by haematology/oncology following formal histological subtyping and staging. Metastatic squamous cell carcinoma in a neck node is managed via the head and neck cancer MDT pathway, as described in that article, with treatment directed at both the primary tumour and the involved neck. Carotid body tumours and salivary gland tumours are managed surgically by specialist vascular or head and neck teams respectively.

Red flags

Prognosis

Prognosis is entirely dependent on the underlying cause: reactive lymphadenopathy resolves fully once the trigger settles, and congenital lesions are effectively cured with complete surgical excision. Malignant causes follow the prognosis of the specific disease and stage, detailed in the relevant articles on head and neck cancer and thyroid cancer - underscoring why establishing the precise cause of a persistent neck lump, rather than treating it as a single generic problem, is the entire point of the work-up.¹