Tuberculous lymphadenitis is a condition that may be considered the location of the primary tuberculous lesion, as well as the development of post-primary tuberculosis. Tuberculous bacilli that have entered the lymph nodes in conditions of decreased immunity of the organism cause a cycle of changes in a specific group of lymph nodes.

Tuberculous lymphadenitis

Tuberculosis of the lymph nodes can be considered the development of post-primary tuberculosis or the location of the primary tuberculous lesion. The ailment occurs as a result of reduced immunity of the body, during which tuberculosis mycobacteria penetrate the lymph nodes and cause a cycle of changes in them. Lymph node involvement by tuberculosis is the second most common disease after extrapulmonary tuberculosis localization. The submandibular lymph nodes are most often affected, but other parts of the body may also be affected. In countries with high prevalence of tuberculosis, it is mostly children who suffer. However, where the situation is stabilized – adults aged 20-40 suffer from tuberculosis. Men are more likely to suffer from tuberculous lymphadenitis than women.

One of the factors influencing the development of the disease may be AIDS. In such patients, tuberculous lymphadenitis is found in 22% of cases.

The causes of tuberculous lymphadenitis

Tuberculous lymphadenitis is usually a local symptom of a generalized infection. Mycobacteria first travel to the lungs, from there to the lymph nodes, and the cavities and mediastinum. There, in turn, due to unfavorable conditions, e.g. reduced immunity, the disease spreads further.

The lymph nodes are spread through the blood from foci in the lung parenchyma or through the lymph from the mediastinal lymph nodes. It is also said that lymph node involvement may result from direct implantation of mycobacteria into the tonsils, skin, mucous membranes or salivary glands.

Symptoms of tuberculous lymphadenitis

The consequence of tuberculous changes in the lymph nodes, e.g. in the neck, is their gradual enlargement, flabbiness, cracking and piercing through the skin outside the purulent discharge, in which there are numerous mycobacteria visible under the microscope. The knot shrinks as soon as the liquid necrotic part is removed and the wall begins to collapse. A star-shaped scar forms on the skin at the site of the fistula.

As a result of contact, other lymph nodes may be infected with mycobacteria, which start the above-mentioned cycle from the beginning in the same way. This progress may take several months or several years. Fortunately, thanks to the availability of many anti-tuberculosis preparations, it is relatively rare.

  1. Grade I lymph node involvement: they are hard, the skin above them is unchanged, and the nodes themselves are “sliding”;
  2. Stage II lymph node involvement: the skin becomes red;
  3. Grade III and IV lymph node involvement: characterized by the softening of the lymph nodes which, when palpated, manifest themselves as fluffiness;
  4. Grade V lymph node involvement: skin fistulas are formed that do not want to heal. These fistulas have periods of remission and periods of exacerbation during which pus is secreted from the fistulas.

Children with tuberculosis involving the lymph nodes may develop paroxysmal cough, shortness of breath, wheezing and respiratory failure. In adults, symptoms of airway obstruction are usually absent.

In turn, the general symptoms include:

  1. lack of appetite;
  2. weight loss;
  3. low-grade fever;
  4. bad mood;
  5. general weakness;
  6. chest pain (with mediastinal involvement).

Diagnosis of tuberculous lymphadenitis

The following tests are performed in the diagnosis of tuberculous lymphadenitis.

1. Chest X-ray – during the examination, radiological changes in the chest area are found in almost half of the patients. Usually tuberculosis affects the peritracheal nodes and the nodes of the cavities. In addition, thanks to this examination, the doctor can detect the presence of calcification in the chest area and peripheral lymph nodes; pleural thickening; parenchymal infiltrates.

2. Computed tomography – reveals the typical localization and picture of tuberculous mediastinitis. After using the contrast medium, nodes with a diameter greater than two cm show a lower density in the central part and reinforcement in the peripheral part. Smaller knots also show uneven density.

3. Bacteriological and histopathological examination – the first is performed on the basis of a material in the form of a smear from a fistula or a fragment of a lymph node. Microscopic examination of the collected lesions allows the detection of mycobacteria in up to 60% of patients with tuberculosis of the lymph nodes. The traditional cultures are up to 80% positive.

4. Fine needle puncture – is used to collect material when peripheral lymph nodes are involved. Histopathological examination then reveals the image of granulation with cheeseization. This method may cause complications in the form of fistulas, therefore it is not recommended as a diagnostic method in the diagnosis of tuberculosis of the lymph nodes.

5. Mediastinoscopy / transbronchial biopsy – tests involving the collection of material for examination in order to diagnose tuberculosis in the presence of lesions in the mediastinal nodes or cavities.

6. Polymerase chain reaction (PCR) – it is a test for the presence of genetic material of mycobacteria. The advantage is the short duration and high specificity (approx. 98%).

Note: Tuberculous lymphadenitis must be distinguished from other diseases that also include lymphadenopathy. For example:

  1. mononucleosis;
  2. cat scratch disease;
  3. brucellosis;
  4. infection with non-tuberculous mycobacteria;
  5. tularemia;
  6. beryllose;
  7. actinomycetes,
  8. lymphoma,
  9. lymphocytic leukemia;
  10. sarcoidosis;
  11. tumor metastasis.

Treatment of tuberculous lymphadenitis

Treatment of tuberculous lymphadenitis is mainly anti-tuberculosis treatment, including:

  1. rifampicin (RMP) – 10 mg / kg bw / day,
  2. isoniazidem – 5 mg / kg bw / day,
  3. pyrazinamide (PZA) – 20-30 mg / kg bw / day.

The patients take all three drugs for two months, and then continue therapy with the two drugs, RMP and INH for four months. During treatment, enlargement of the lymph nodes is seen in some patients and is explained as over-reactivity to tuberculoprotein released from disintegrating macrophages during treatment.

Surgical management (in times of successful antituberculosis chemotherapy) is implemented mainly for diagnostic purposes and in special situations, such as pus discharge or removal of mediastinal lymph nodes, which, despite the treatment, still narrow the airways. Special situations apply mainly to children.

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