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.