Define Cervical Lymphadenopathy. Describe its causes, investigations and management.

The Concept

Enlargement of the cervical lymph nodes is extremely common, and the whole art is separating the trivial from the sinister. The causes fall into three broad groups — reactive/inflammatory, specific infection (notably tuberculosis), and neoplastic (metastatic carcinoma or lymphoma) — and the character of the nodes plus the patient's age usually indicates which group is responsible.

Causes

• Reactive (inflammatory) — the commonest: acute tender nodes accompanying an upper respiratory, throat or dental infection, and chronic reactive nodes. These are soft, tender and mobile.
• Tuberculous lymphadenitis — a chronic, often matted group of nodes that may caseate to form a 'cold abscess', which can point through the deep fascia as a 'collar-stud' abscess and discharge as a chronic sinus. Other specific infections include HIV, toxoplasmosis and cat-scratch disease.
• Metastatic carcinoma — typically a hard, fixed node, most often squamous carcinoma from a head-and-neck primary (also thyroid and, at the left supraclavicular Virchow's node, from the abdomen).
• Lymphoma — characteristically rubbery, multiple, non-tender nodes, often with systemic 'B symptoms' (fever, night sweats, weight loss).

Assessment

The examination reads the nodes like a diagnostic text: their number and site, consistency (soft = reactive, rubbery = lymphoma, stony-hard = metastatic), mobility or fixity, tenderness, and matting (suggesting TB). One then searches for a primary in the head and neck and assesses for systemic features.

Investigations

FNAC is the first-line test and ultrasound characterises the nodes. For a suspected metastatic squamous node, an ENT panendoscopy with biopsy hunts for the primary. If lymphoma is suspected, an excision biopsy of a whole node is required — because diagnosis and subtyping depend on the architecture, which FNAC cannot show. Tuberculous nodes are confirmed by Ziehl-Neelsen staining, culture and histology (caseating granulomas).

Management

Treatment is directed at the cause: antibiotics for bacterial lymphadenitis, a full course of anti-tuberculous chemotherapy for TB, treatment of the primary plus neck dissection for metastatic carcinoma, and chemotherapy/radiotherapy for lymphoma.

Tuberculous Lymphadenitis in Detail

TB cervical nodes (scrofula) deserve emphasis in this setting. They typically present as a chronic, painless, matted mass of nodes in a young adult, which may progress through stages: firm discrete nodes → matting → caseation forming a fluctuant 'cold' abscess (cold because it lacks the heat of acute inflammation) → the pus tracking through the deep fascia to form a 'collar-stud' abscess → discharge as a chronic non-healing sinus. Diagnosis is by FNAC/biopsy (caseating granulomas, acid-fast bacilli) and treatment is a full course of anti-tuberculous chemotherapy, not primarily surgery.

Lymphoma — WHY Excision Biopsy

The reason lymphoma demands an excision (or generous core) biopsy rather than FNAC is fundamental: classifying a lymphoma — and therefore choosing treatment — depends on the nodal architecture and immunohistochemistry, which need an intact node. A cytology smear showing lymphocytes cannot distinguish reactive change from lymphoma or subtype it, so a suspicious rubbery node with systemic symptoms goes to excision biopsy.

The Metastatic Neck Node — a Structured Search

When a node is judged metastatic, the search for the primary is systematic: a thorough examination of the scalp, skin, oral cavity, oropharynx, nasopharynx, larynx and hypopharynx, followed by examination under anaesthesia with panendoscopy and biopsy of any suspicious mucosa, and cross-sectional imaging (CT/MRI) and increasingly pet-CT to find an occult primary. Only when a primary is truly not found (a genuine 'occult primary') is the neck itself treated. This disciplined hunt reflects the principle that treating a metastatic node without addressing its source is futile.

Virchow's Node & Distant Primaries

Not every metastatic cervical node comes from a head-and-neck primary. The classic exception is Virchow's node — an enlarged left supraclavicular node (Troisier's sign) — which receives thoracic-duct drainage and characteristically signals an abdominal or thoracic primary, most famously gastric carcinoma (also pancreatic, oesophageal, testicular, or lymphoma). Finding such a node therefore redirects the search to the abdomen and chest rather than the upper aerodigestive tract, a distinction that examiners like to test and that changes the entire investigative pathway.

A Summary of the Approach

The safe endpoint is a firm rule set: read the nodes by consistency and matting; investigate with FNAC and ultrasound; excision-biopsy only for suspected lymphoma; panendoscopy to find the primary of a metastatic squamous node; and never blindly excise an undiagnosed node. Treatment then follows the cause. This discipline reliably distinguishes the benign reactive node from the tuberculous mass and the sinister metastasis.

In adults, a hard fixed node is metastatic until proved otherwise.

• Three groups: reactive/inflammatory, specific infection (TB), neoplastic (metastatic carcinoma, lymphoma).
• Consistency reads the cause: soft/tender = reactive, rubbery/multiple = lymphoma, stony-hard/fixed = metastatic; matted ± cold abscess = TB.
• FNAC + ultrasound first-line; panendoscopy to find the primary of a metastatic squamous node.
• Suspected lymphoma → excision biopsy (architecture needed), not FNAC; TB → ZN stain, culture, caseating granulomas.
• Treat the cause: antibiotics / anti-TB therapy / treat primary + neck dissection / chemo-radiotherapy for lymphoma.