Granuloma

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Granuloma
Synonyms Granulomatous inflammation
Pronounce
Field N/A
Symptoms Often asymptomatic, may cause local swelling or systemic effects depending on the underlying cause
Complications Tissue damage, fibrosis, organ dysfunction, chronic inflammation
Onset Gradual
Duration Chronic
Types Caseating granuloma, Non-caseating granuloma, Foreign body granuloma, Immune granuloma
Causes Chronic infections, autoimmune disorders, foreign body reactions, persistent irritants
Risks Exposure to tuberculosis, fungal infections, sarcoidosis, environmental pollutants
Diagnosis Histopathology, Biopsy, Imaging studies, Microbiological tests
Differential diagnosis Neoplasm, Abscess, Fibrosis
Prevention Avoid exposure to known infectious agents and persistent irritants
Treatment Treat underlying cause; antibiotics, immunosuppressants, surgical excision in some cases
Medication Corticosteroids, Anti-tuberculosis drugs, Antifungal medications
Prognosis Depends on the underlying disease; often resolves if the cause is treated
Frequency Common in infectious and inflammatory diseases
Deaths Rare, except in severe systemic conditions


Granuloma is a specialized form of chronic inflammation characterized by the formation of compact, often microscopic, nodular lesions composed of immune cells. These structures primarily consist of macrophages, lymphocytes, epithelioid cells, and multinucleated giant cells. Granulomas serve as a defensive immune mechanism, isolating foreign substances, pathogens, or irritants that the body is unable to eliminate. They commonly occur in response to persistent infections, chronic inflammatory conditions, autoimmune diseases, and foreign material exposure.

Granulomas are commonly observed in diseases such as tuberculosis, sarcoidosis, leprosy, fungal infections, and chronic granulomatous disease.

Granuloma in tropical diseases

Pathophysiology[edit | edit source]

Granulomas form when the immune system attempts to wall off substances that it perceives as foreign but cannot eliminate. These substances include:

The formation of a granuloma follows these steps: 1. Chronic antigen exposure – The immune system encounters a persistent irritant or pathogen. 2. Macrophage activation – Macrophages attempt to engulf and digest the irritant but fail. 3. T-cell recruitment – Helper T lymphocytes (CD4+) release cytokines like interferon-gamma and tumor necrosis factor-alpha (TNF-α), which activate more macrophages. 4. Formation of epithelioid cells – Macrophages enlarge and fuse, forming multinucleated giant cells (e.g., Langhans giant cells). 5. Fibrosis and encapsulation – Over time, fibroblasts deposit collagen, forming a fibrous capsule around the granuloma.

Granulomas can be classified based on their morphology:

  • Caseating granulomas – Contain necrotic tissue, often seen in tuberculosis.
  • Non-caseating granulomas – Do not contain necrosis, commonly seen in sarcoidosis and Crohn's disease.
  • Foreign body granulomas – Form around exogenous materials like talc, sutures, or implants.

Clinical Manifestations[edit | edit source]

Granulomas can be asymptomatic or cause a variety of symptoms depending on their size, location, and underlying cause.

Localized Symptoms[edit | edit source]

Systemic Symptoms[edit | edit source]

  • Fever
  • Fatigue
  • Weight loss
  • Night sweats
  • Joint pain (associated with sarcoidosis and autoimmune diseases)

Diagnosis[edit | edit source]

The definitive diagnosis of a granuloma requires histopathological examination. The diagnostic workup includes:

  • Histology – Biopsy with identification of epithelioid histiocytes, multinucleated giant cells, and lymphocytic infiltration.
  • Acid-Fast Stain – Detects Mycobacterium tuberculosis in caseating granulomas.
  • Fungal Stains (GMS, PAS) – Identify fungal infections like histoplasmosis.
  • Imaging Studies – Chest X-ray and CT scan can reveal pulmonary granulomas.
  • Serologic and PCR tests – Used to identify underlying infectious causes.
  • Blood tests – Elevated angiotensin-converting enzyme (ACE) in sarcoidosis.

Treatment[edit | edit source]

Treatment depends on the underlying cause of granuloma formation:

  • Infectious Granulomas
  • Tuberculosis – Anti-tubercular therapy (e.g., isoniazid, rifampin, ethambutol, pyrazinamide)
  • Fungal granulomas – Antifungal therapy (e.g., amphotericin B, itraconazole)
  • Leprosy – Dapsone, rifampin, clofazimine
  • Autoimmune and Idiopathic Granulomas
  • Corticosteroids – Used in sarcoidosis, Crohn’s disease, and Wegener’s granulomatosis.
  • Immunosuppressants – Methotrexate, azathioprine for autoimmune conditions.
  • Foreign Body Granulomas
  • Surgical removal – Necessary when granulomas cause obstruction or severe symptoms.
  • Steroid injections – Reduce inflammation in skin and soft tissue granulomas.

Prognosis[edit | edit source]

The prognosis of granulomas varies depending on the underlying condition:

  • Tuberculosis granulomas – Can resolve with proper antibiotic therapy but may lead to fibrosis or lung cavitations if untreated.
  • Sarcoidosis granulomas – Often resolve spontaneously but can progress to chronic fibrosis.
  • Fungal granulomas – Require prolonged antifungal treatment; relapse is possible.
  • Foreign body granulomas – Usually persist until the irritant is removed.

See Also[edit | edit source]








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Contributors: Prab R. Tumpati, MD