In granulomatous inflammation, the epithelioid cell is derived from:
- A Macrophages activated by IFN-gamma ✓
- B CD4+ T lymphocytes stimulated by IL-4
- C Neutrophils that have undergone phagocyte exhaustion
- D Fibroblasts activated by TGF-beta
Correct answer: A. Macrophages activated by IFN-gamma
Explanation
Epithelioid cells are activated macrophages that have been stimulated by IFN-gamma (secreted by CD4+ Th1 cells). They have abundant pale pink cytoplasm (resembling squamous/epithelial cells, hence 'epithelioid'), reduced phagocytic capacity, and enhanced secretory function. They can fuse to form Langhans-type or foreign-body-type giant cells. Granuloma formation is a T-cell dependent process driven by the Th1 response.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.