A 60-year-old man with gout has a tophus on his ear. Histologically, urate crystals are surrounded by which type of giant cells, and what cytokine drives their formation?
- A Touton giant cells — IL-4-driven lipid-laden macrophage fusion
- B Foreign body giant cells (osteoclast-type) — IL-4/IL-13–driven macrophage fusion around insoluble material ✓
- C Langhans giant cells — IFN-gamma–driven immune granuloma
- D Warthin-Finkeldey giant cells — viral cytopathic effect
Correct answer: B. Foreign body giant cells (osteoclast-type) — IL-4/IL-13–driven macrophage fusion around insoluble material
Explanation
Tophaceous urate deposits elicit a foreign body granuloma with foreign body giant cells (randomly distributed nuclei, osteoclast-type), formed by macrophage fusion driven by IL-4 and IL-13. Touton giant cells (foamy cytoplasm, peripheral wreath of nuclei) occur in fat-containing lesions like xanthomas. Langhans cells (peripheral nuclei) indicate immune granulomas (TB, sarcoid). Warthin-Finkeldey giant cells are pathognomonic of measles.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.