Epithelioid cells and giant cells are derived from

# Epithelioid cells and giant cells are derived from macrophages and are important in the development of:
A. Initial inflammation
B. Granulomatous inflammation
C. Acute inflammation
D. Subacute inflammation

The correct answer is B. Granulomatous inflammation.

Granulomatous inflammation is a subtype of chronic inflammation and is characterized by granulomas, which are nodular collections of specialized macrophages referred to as epithelioid cells. A rim of lymphocytes usually surrounds granulomas. Granulomas are produced by multinucleated giant cells (Langerhans giant cells and foreign body giant cells). All the other cell types characteristic of chronic inflammation, including plasma cells, eosinophils, and fibroblasts, may also be associated with granulomas.

Note: Granulomatous inflammation is characteristically associated with areas of caseous necrosis produced by infectious agents, particularly Mycobacterium tuberculosis.

• Tuberculosis: caused by the inhalation of Mycobacte1ium tuberculosis. Oral non-healing chronic ulcers follow lung infection. Important: Characterized by caseating granulomas with multinucleated giant cells (Langerhans giant cells and foreign body giant cells).

Etiologic agents associated with granulomatous inflammation:

• Infectious agents

- TB and leprosy, which are mycobacterial diseases

- Fungal infections (blastomycosis, histoplasmosis, and coccidioidomycosis)

- Spirochetes (Treponema pallidum, which causes syphilis)

- Cat scratch disease (caused by an unnamed gram-negative organism)

• Foreign material (e.g., suture or talc)

• Sarcoidosis (unknown etiology; it is non-necrotizing)

• Crohn's disease (it is non-caseating)