A 60-year-old woman with advanced ovarian carcinoma develops a murmur. Echocardiography reveals small, sterile, firm vegetations on multiple valves bilaterally, particularly on the line of valve closure. She has no fever and blood cultures are negative. Vegetation histology shows fibrin and platelets without neutrophils. What is this condition and its pathological basis?

• A Libman-Sacks endocarditis — immune complex-mediated valve inflammation in SLE
• B Carcinoid heart disease — serotonin-mediated fibrosis of right-sided valves
• C Non-bacterial thrombotic endocarditis (NBTE/marantic endocarditis) — bland fibrin-platelet thrombi in a hypercoagulable state from malignancy ✓
• D Rheumatic fever endocarditis — Aschoff bodies in valve leaflets secondary to anti-streptococcal cross-reactivity

Explanation

Non-bacterial thrombotic endocarditis (NBTE), also called marantic endocarditis, occurs in hypercoagulable states — most classically mucin-secreting adenocarcinomas (pancreatic, ovarian, gastrointestinal). Mucin activates clotting cascades producing a hypercoagulable state that deposits bland, sterile fibrin-platelet thrombi along valve closure lines. Vegetation histology lacks inflammatory cells. Clinically, NBTE causes embolic strokes. Libman-Sacks endocarditis (SLE) has vegetations on both surfaces of mitral valve and is associated with antiphospholipid syndrome. Carcinoid affects right-sided valves via serotonin-induced fibrous plaques. Rheumatic fever has Aschoff nodules with granuloma-like lesions.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.