Lymph Node TB

What is TB of the Lymph Nodes?

Also called Tubercular Lymphadenitis

Used to be called Scrofula or King’s evil

The TB of the lymph nodes is the most common form of extra-pulmonary TB

Constitutes nearly 30% of all Extra-Pulmonary TB

More common in women and children

Lymphadenopathy is quite often bilateral (both sides)

It is non-contagious

Pulmonary involvement in 5% to 62% of cases

Lymph nodes involved are –
- Neck region -posterior and anterior cervical chains
- Below jaw – submandibular
- Behind ears – periauricular
- Pelvic area – inguinal
- Under Arms area -axillary groups
- Inside chest area -hilar, Para tracheal and mediastinal .
- abdominal lymph nodes

Causes of Lymph Node TB

Spreads via the blood stream from Pulmonary loci or other organs of tubercular involvement. Mycobacterium tuberculosis is the main culprit

Clinical effects on Lymph nodes at different places

INTRA-THORACIC NODES
- Could compress one of the bronchus
- This can lead to lung infection
  - Bronchiectasis
  - Atelectasis
  - Chylous effusion in thoracic duct

Complications like –
- Oesophago-Mediastinal fistula
- Tracheo-Oesophageal Fistula
- Dysphagia
- Biliary Obstruction
- Cardiac Temponade

RETRO-PERITONEAL NODES
- May lead to chylous ascites
- May lead to chyluria

Causes of Lymph Node TB

Spreads via the blood stream from Pulmonary loci or other organs of tubercular involvement. Mycobacterium tuberculosis is the main culprit

Differential diagnosis

It has to be differentiated from other causes of lymphadenopathy, such as –
- Reactive hyperplasia
- Lymphoma
- Sarcoidosis
- Secondary carcinoma
- Generalised lymphadenopathy of HIV
- Kaposi sarcoma
- Lymphadenitis caused by Mycobacteria other than tuberculosis (MOTT)
- Fungi
- Toxoplasmosis.

Usually, matting, multiplicity and caseation are features of tuberculous lymphadenitis but these changes are not sensitive and neither are they specific

In lymphoma, nodes are rubber-like and very less matted

Due to secondary carcinoma the nodes are hard and fixed to overlying skin or underlying structures

Symptoms of Lymph node TB

Gradually increasing painless swelling of lymph nodes

Duration from few weeks to months

Sometimes fever

Sometimes Weight loss

Sometimes Fatigue

Sometimes Night sweats

Distressing cough In mediastinal lymphadenitis

On examination, the quality of lymph nodes is like
- Initially nodes are firm, mobile and discrete
- Overlying skin is free
- Later, nodes become matted
- And overlying skin gets inflamed
- In advanced stage, it forms abscesses and sinus tracts
- Very large nodes compress or invade surrounding structures

How to confirm Diagnosis of tuberculous lymphadenitis?

Firm diagnosis requires physical demo of mycobacteria

Many may not show in smears, but ultimately be tubercular

History of exposure from pulmonary tuberculosis is highly suggestive

Tuberculin skin test is positive in most of patients, probability of false negative test is less than 10%

X-ray chest will show if presence or absence of any active or healed pulmonary lesion. Or any other co-existent intra-thoracic disease

Ultrasound examination and CT scan of chest/abdomen can show enlarged lymph nodes as hypodense areas with rim enhancement or calcification. Also show any adjoining organs involvement

Smears show presence in upto 75% cases. Done by FNAC-Fine needle aspiration cytology or excision biopsy shows features of tuberculous lymph nodes as epitheloid cell granulomas, multinucleated giant cells and caseation necrosis

Sometimes Invasive procedures like mediastinoscopy, video assisted thoracoscopy or tranbronchial methods may be required in detecting intrathoracic disease

Treatment

(Tuberculous lymphadenitis involves the organ-systems and not just the lymph nodes)

Chemotherapy found effective
- A time of 9 month duration advised.
- Use of isoniazid, rifampicin and ethambutol for first 2 months.
- Followed by isoniazid and rifampicin for 7 months
- Alternatively some favour a 6 month regime.

Steroids reduce inflammation in early phase of therapy –found useful in intrathoracic region when heart or lungs get compressed. Dose of Prednisolone given at 40 mg / day for 6 weeks followed by gradual tapering

Surgical excision may be used alongside chemotherapy but no use by itself

Prognosis of Tubercular Lymphadenitis

The following conditions call for a new approach to seek better ways of management of TB lymphadenopathy –
- Appearance of freshly involved nodes
- Enlargement of the existing nodes
- Development of fluctuation
- Appearance of sinus tracts
- Residual lymphadenopathy after completion of treatment
- Relapses

The probable reasons for the above are as follows-
- Unidentified drug resistance,
- Poor drug penetration into the lymph node,
- Unfavourable local milieu
- Enhanced delayed hypersensitivity reaction in response to mycobacterial antigens released during medical treatment of the disease.

Duration of Treatment
- The optimal duration of antimicrobial therapy is unclear.

Management of lymph node tuberculosis ?

Take proper care in diagnosis and evaluation is a must and close monitoring is the key in TB lymph node management

Record all possible sites of involvement, as also the nature and size at start of treatment

To identify any co-existing disease

Keeping close watch as some nodes may enlarge first, and then ultimately respond

Due to changes in spread, aspiration may be required

Any bacterial infection secondary to be dealt with including incision and drainage

Full chain of involved lymph nodes may have to be done if condition worsens after 8 weeks of treatment to avoid appearance of ugly sinus tracts

Resective surgery needed for Non healing sinus tracts

To observe Residual lymph nodes after treatment is completed. Any changes in size or symptoms will need excisional biopsy for histopathology and culture. Usually these patients respond with the same treatment

Ensure that the causative agent is isolated and sensitivity testing done and chemotherapy modified in accordance

HIV co-infection tends to make greater involvement of lymph nodes even more common than due to lymphoma or generalised HIV lymphadenopathy .The features are as under-
- Patients are males and older
- Multiple site involvement is more common
- Severity is higher
- Anterior and posterior mediastinal group are more involved.
- In HIV seropositive patients, there is tender lymphadenopathy; there is fever or weight loss as also a co-existing pulmonary tuberculosis than in HIV seronegatives patients.

Lymph Node TB

Lymph Node TB

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