Echocardiography in a 35-year-old woman with active SLE shows mobile masses on the atrial surface of the posterior mitral leaflet. Histology of the lesion would most likely show which feature?

• A Vegetations with central fibrinoid necrosis and proliferating vessels but no bacteria ✓
• B Bacterial colonies within fibrin
• C Myxomatous degeneration of the leaflet with mucopolysaccharide accumulation
• D Fibrous calcified nodules along the line of leaflet closure

Explanation

Libman-Sacks endocarditis produces sterile verrucous vegetations, typically on either surface of the mitral valve, containing fibrin, platelets, and inflammatory cells with central fibrinoid necrosis and later vascular proliferation; organisms are absent by definition. Bacterial colonies indicate infective endocarditis, myxomatous change describes mitral valve prolapse, and calcified nodules along closure lines describe degenerative calcific aortic stenosis-like change, not this lesion.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.