Nonbacterial thrombotic endocarditis involving all four cardiac valves.

This report describes a case of nonbacterial thrombotic endocarditis caused by Waldenström macroglobulinemia, with diffuse endocardial lesions and involvement of all 4 cardiac valves. A 77-year-old man presented with heart failure due to severe regurgitation of all 4 cardiac valves; surgical repair using bioprosthetic valves was indicated. A pathological study revealed fibrin-triggered thrombus formation that confirmed the diagnosis of nonbacterial thrombotic endocarditis. In cases of nonbacterial thrombotic endocarditis, the underlying cause should be investigated.