A patient with rheumatic mitral stenosis has LA thrombus. Histologically, mitral valve leaflets show Aschoff nodules. The characteristic Aschoff cell (Aschoff giant cell) is derived from which cell lineage?

• A Activated T-lymphocytes undergoing cytoplasmic clearing
• B Myofibroblasts transforming in response to streptococcal antigens
• C Interstitial cardiac fibroblasts activated by anti-M protein antibodies
• D Macrophages (histiocytes) with multinucleation — mesenchymal macrophage-derived ✓

Explanation

Aschoff cells are multinucleated giant cells derived from activated macrophages/histiocytes that accumulate around zones of fibrinoid necrosis in the myocardium during acute rheumatic carditis. They show characteristic owl-eye or caterpillar-shaped nuclei with prominent nucleoli (Anitschkow cells are the mononuclear form, called 'caterpillar cells' due to the wavy chromatin bar). The entire Aschoff nodule represents a granulomatous-like structure with central fibrinoid necrosis surrounded by lymphocytes, plasma cells, and Aschoff/Anitschkow cells.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.