Which structure of the aortic wall is primarily involved in the pathogenesis of syphilitic aortitis?

• A Endothelium of the intima
• B Aortic valve commissures directly by spirochetes
• C Subendocardial myocardium
• D Vasa vasorum of the adventitia ✓

Explanation

In tertiary syphilis, Treponema pallidum infects the vasa vasorum of the adventitia, causing obliterative endarteritis. Ischaemia of the media leads to destruction of elastic tissue and smooth muscle, dilatation of the ascending aorta, aneurysm formation, and calcification. Grossly the intima shows wrinkled 'tree bark' appearance. The valve ring dilatation causes aortic regurgitation, but valve leaflets themselves are not destroyed, which separates syphilitic from rheumatic aortic regurgitation.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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