Lecture Notes: Ghon's Complex and Tuberculosis

Introduction

• Focus on Ghon's Complex, associated with primary tuberculosis.
• Tuberculosis: Disease caused by Mycobacterium tuberculosis.
  • Two types: Primary and Secondary.
  • Primary Tuberculosis:
    • First time infection, mostly in children.
    • Affects lungs, but can also affect the small intestine if bacteria ingested.
  • Secondary Tuberculosis:
    • Re-infection or reactivation.

Ghon's Complex

• Lesion seen in primary tuberculosis.
• Consists of three components:
  • Ghon's focus (lesion at the portal of entry)
  • Draining lymphatic vessel
  • Lymph node

Definition

• Ghon's Complex is the lesion produced at the tissue of portal entry, consisting of:
  • A foci
  • Draining lymphatics
  • Lymph node

Locations

• If inhaled: Found in lung and associated hilar lymph node.
• If ingested: Found in small intestine and associated mesenteric lymph node.

Components of Ghon's Complex

• Pulmonary Component:
  • Ghon's focus (1-2 cm, typically affects upper part of lower lobe)
  • Caseous pneumonia
• Lymphatic Vessel Component:
  • Lymph contains phagocytes with bacilli
• Lymph Node Component:
  • Hilar lymph node (lung)
  • Enlarged, shows granuloma and caseous necrosis under microscope

Microscopy

• Granuloma:
  • Central caseous necrosis
  • Surrounding epithelioid cells (macrophages)
  • Epithelioid cells can form Langhans giant cells
  • Encased by fibroblasts (fibrosis)
• Enlarged Mesenteric Lymph Nodes:
  • Known as Tabes Mesenterica
  • Can rupture leading to tuberculous peritonitis

Fate of Primary Tuberculosis

• Can heal by fibrosis or calcification.
• Lung:
  • Progressive primary tuberculosis in immunocompromised (spreads to both lungs)
  • Dissemination through bronchi
• Systemic Spreading:
  • Hematogenous spread leading to primary miliary tuberculosis
  • Reactivation can cause secondary tuberculosis

Treatment

• Full treatment with adherence to prevent reactivation.
• DOTS Therapy (Directly Observed Treatment, Short-course):
  • Ensures compliance with treatment due to high tuberculosis burden.

Conclusion

• Understanding of Ghon's Complex and the importance of proper management of tuberculosis.
• Emphasized to draw and label diagrams in exams for better understanding and scoring.