Lymphadenopathy Overview

Lymphadenopathy

• Lymphadenopathy refers to a disease of the lymph nodes, characterized by abnormality in size or consistency.
• Lymphadenopathy can either be inflammatory or neoplastic in nature.

Acute Lymphadenitis

• Acute non-specific Lymphadenitis: Occurs in nodes draining acutely inflamed areas, such as during acute suppurative tonsillitis.
  • Grossly: Acutely inflamed nodes are enlarged and tender.
  • Microscopically: Large germinal centers are present; Neutrophilic infiltration with abscess formation can be seen in severe cases.

Chronic Non-specific Lymphadenitis

• Changes in LN due to prolonged inflammation, infection, etc.
• Also known as reactive hyperplasia.
• The most common reason for lymph node enlargement.

Chronic Specific Lymphadenitis:

• TB Lymphadenitis:
  • Common cause of lymph node enlargement, usually a primary infection in children.
  • Commonest Sites:
    • Cervical LNs: Infected from tonsils.
    • Mediastinal LNs: Infected with primary pulmonary TB.
    • Mesenteric LNs: Infected due to ingestion of infected milk ("Tabes mesenterica").
  • Microscopically:
    • Early Tuberculous Lymphadenitis: Infiltration by multiple small, pale tubercles formed of aggregates of epithelioid cells, few Langhans giant cells, and minimal caseation.
    • Caseating Tuberculous Lymphadenitis: Most nodal tissue is replaced by areas of caseous necrosis with multiple small tubercles at the periphery.

Caseating TB Lymphadenitis

• Early: Characteristic pale tubercles.
• Caseating: Caseous necrosis within lymph node.

Cold Abscess

• Formation: Accumulation and liquefaction of caseous material, surrounded by TB granulation tissue and fibrosis.
• Complication: Complicates TB of lymph nodes, bones, joints, and epididymis.
• Progression: May open to the outside, leading to multiple sinuses.

Sarcoidosis

• An inflammatory disease of unknown cause: Affects multiple organs, primarily the lungs and lymph nodes.
• Formation: Abnormal masses (non-caseating granulomas) are formed in different organs.
• Microscopically:
  • Well-circumscribed epithelioid granulomata with giant cells surrounded by lymphocytes.
  • Two characteristic inclusions inside giant cells:
    • Schaumann bodies: Laminated calcified bodies.
    • Astroid bodies: Star-shaped inclusions.
  • Fibrosis is a common feature.

Infectious Mononucleosis

• Caused by Epstein-Barr virus (EBV).
• Common in teenagers but can occur at any age.
• Transmission: Spread through saliva ("the kissing disease").
• Symptoms: Pain, sore throat, fever, jaundice.

Cat Scratch Disease (CSD)

• Caused by the bacterium Bartonella henselae.
• Carried by cats: Infection does not make cats sick but can cause symptoms in people through scratches or bites.
• Lymph node presentation: Swollen lymph nodes forming stellate abscesses.

This quiz covers the characteristics and classifications of lymphadenopathy, including acute and chronic lymphadenitis. It highlights key features of non-specific and specific lymphadenitis, including causes and pathological changes. Test your knowledge on this critical topic in pathology!