Non-bacterial thrombotic endocarditis (NBTE, marantic endocarditis) is characterized by sterile vegetations. Which histological feature distinguishes its vegetations from those of infective endocarditis?
- A Large, friable vegetations with gram-positive cocci and dense neutrophilic infiltrate
- B Warty vegetations on both surfaces of valve leaflet in a patient with rheumatic fever
- C Small, flat, bland fibrin-platelet thrombi along line of closure without valve destruction or neutrophils ✓
- D Calcified vegetation with no cellular infiltrate in elderly patients
Correct answer: C. Small, flat, bland fibrin-platelet thrombi along line of closure without valve destruction or neutrophils
Explanation
NBTE vegetations consist of bland, sterile thrombi (fibrin and platelets) deposited along the line of valve closure, without valve destruction, inflammation, or bacterial colonies. They occur in debilitated patients with hypercoagulable states or cancer (Trousseau's syndrome). Infective endocarditis shows large friable vegetations with organisms and PMNs. Libman-Sacks endocarditis (SLE) has small warty vegetations on both surfaces. Calcific aortic stenosis involves leaflet calcification, not vegetations.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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