Tuberculous Lymphadenitis
Pathogenesis and Pathophysiology
Tuberculous lymphadenitis is the most common extrapulmonary form of tuberculosis, involving granulomatous inflammation and caseous necrosis. Timely diagnosis and treatment prevent complications.
Tuberculous Lymphad
enitis: Pathogenesis and Pathophysiology
Introduction
Tuberculous lymphadenitis, commonly known as scrofula, is the most frequent extrapulmonary manifestation of tuberculosis (TB). It occurs when Mycobacterium tuberculosis infects the lymph nodes, particularly cervical nodes.
Pathogenesis
The pathogenesis of tuberculous lymphadenitis begins with the inhalation of Mycobacterium tuberculosis. The bacteria then spread through hematogenous or lymphatic routes, leading to lymph node involvement.
- Primary Infection: The bacilli enter the host via the respiratory system.
- Immune Response: Macrophages engulf the bacteria, forming granulomas.
- Caseous Necrosis: Granulomatous inflammation leads to necrotic tissue in the lymph nodes.
Pathophysiology
The hallmark of tuberculous lymphadenitis is chronic granulomatous inflammation with central caseation. The affected lymph nodes exhibit:
- Granuloma formation with epithelioid cells and Langhans giant cells.
- Central caseation necrosis.
- Progressive enlargement leading to abscess formation.
Clinical Features
Patients commonly present with:
- Painless lymph node swelling.
- Low-grade fever and night sweats.
- Weight loss and fatigue.
Diagnosis
Diagnosis involves:
- Fine-Needle Aspiration Cytology (FNAC): Identifies granulomas and acid-fast bacilli.
- Tuberculin Skin Test: Assesses immune response.
- Polymerase Chain Reaction (PCR): Detects TB DNA.
Treatment
The cornerstone of treatment includes:
- Anti-TB therapy: A combination of isoniazid, rifampicin, ethambutol, and pyrazinamide.
- Surgical drainage in cases of abscess formation.
Conclusion
Tuberculous lymphadenitis remains a significant health concern. Early diagnosis and appropriate treatment are essential for better patient outcomes.