Complications of tuberculosis

Main complications of pulmonary tuberculosis

Within the framework of the national classification developed by phthisiologists, radiologists, and pathologists, a whole spectrum of formidable complications is distinguished, accompanying the course of both primary and secondary tuberculosis. These conditions significantly worsen the prognosis of the disease and often become the direct cause of death.

Key complications of the tuberculous process include:

• Hemoptysis and pulmonary hemorrhage: occur due to erosion (destruction) of blood vessels in the walls of forming or formed cavities.
• Spontaneous pneumothorax: rupture of caseous masses or a cavity wall into the pleural cavity with the ingress of air.
• Cor pulmonale (cardiopulmonary failure): develops against the background of extensive pneumofibrosis and reduction of the pulmonary vascular bed.
• Atelectasis: collapse of a lung lobe or segment due to bronchial obstruction by caseous masses or compression by enlarged lymph nodes.
• Amyloidosis: a systemic complication of chronic inflammation leading to the deposition of amyloid in internal organs and the development of severe renal failure.
• Fistula formation: formation of pathological passages, such as bronchial and thoracic fistulae.

Fungal infections in tuberculosis (Aspergillosis)

One of the specific morphological complications arising in the presence of destruction cavities in the lungs is the addition of a mycotic infection. Most commonly, patients exhibit mold fungal infection — aspergillosis.

The most important form of non-invasive aspergillosis is the formation of aspergillomas. These are dense accumulations of fungal mycelium that form when fungi colonize pre-existing anatomical defects — tuberculous cavities and secondary bronchiectasis.

The morphological picture of aspergilloma is characterized by moderately pronounced chronic inflammation and proliferation of fibrous tissue around the fungal clusters in the cavity wall. Clinically, such a fungal complication manifests as repeated, recurrent episodes of hemoptysis, which aggravates the severity of the underlying disease. The pathogenesis of allergic reactions to mold proceeds as a type III and IV hypersensitivity reaction.

Combined lesions: Silicotuberculosis

A special category consists of complications arising at the intersection of specific infection and occupational interstitial lung diseases (pneumoconioses), specifically silicosis. The proliferation of fibrous tissue in silicosis leads to the compression of bronchi and blood vessels, which in itself causes emphysema and bronchiectasis, but the addition of infection manifold worsens the clinical picture.

Silicotuberculosis — one of the most frequent and clinically formidable complications of silicosis, representing the addition of a tuberculous infection to dust fibrosis.

The morphological characteristics of this condition are unique: histological examination of the lung tissue simultaneously reveals:

1. Typical fibrous silicotic nodules.
2. Specific tuberculous granulomas and caseous changes.
3. Combined silicotuberculous lesions, reflecting the mutually aggravating influence of the two pathological processes.

Role of complications in the Russian classification

For the correct formulation of a diagnosis and understanding of the morphological substrate, it is important to remember the structure of the national tuberculosis classification. It takes into account the pathogenesis, phase of the course, and anatomical localization, as well as the presence of mycobacteria excretion (MTB+ or MTB-).

The disease is divided into major clinical forms:

• Tuberculous intoxication (mainly in children and adolescents).
• Respiratory tuberculosis (from the primary complex and focal form to severe destructive variants: caseous pneumonia, fibrocavernous, and cirrhotic tuberculosis).
• Tuberculosis of other systems (CNS, bones, intestines, kidneys).

Complications (amyloidosis, hemorrhages, pneumothorax) are listed separately in the diagnosis, as are residual changes after a clinically cured process.

Class and exam questions

What else to study on this topic

• Pathogenesis and morphology of tuberculous cavity formation
• Mechanisms of secondary renal amyloidosis development
• Generalized candidiasis in immunocompromised patients
• Differences between caseous pneumonia and fibrocavernous tuberculosis
• Pathogenesis of cor pulmonale in chronic lung diseases

Other topics in the "Additional Topics" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.