In granulomatous inflammation, epithelioid cells are derived from which cell type?
- A Neutrophils undergoing transformation
- B Activated macrophages with abundant pale cytoplasm ✓
- C Plasma cells secreting granule-forming immunoglobulins
- D Lymphocytes stimulated by mycobacterial antigens
Correct answer: B. Activated macrophages with abundant pale cytoplasm
Explanation
Epithelioid cells are activated macrophages characterized by abundant pale eosinophilic cytoplasm resembling epithelial cells (hence the name) and elongated nuclei. They represent macrophages that have ingested material they cannot destroy, undergoing morphological transformation under the influence of IFN-gamma from T lymphocytes. Multinucleated giant cells form by fusion of epithelioid cells. Plasma cells and neutrophils are not precursors.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.