In 1923, Libman 1 characterized the various forms of endocarditis; in the group of uncertain etiology, terminal endocarditis was considered to occur without recognized symptoms at the end of a chronic, debilitating disease. Gross and Friedberg 2 used the descriptive term nonbacterial thrombotic endocarditis (NBTE), segregated the clinical syndromes with which NBTE was associated, and viewed this form of endocarditis as an accidental occurrence in the course of any fatal disease, without clinical significance. Libman3 subsequently noted occasional embolization with NBTE. The historical perspective, conflicting terminology, nature, and pathogenesis of these lesions are contained in reports by Allen and Sirota,4 MacDonald and Robbins,5 Barry and Scarpeli,6 and in a series of studies by others.7-10 As a result of these observations, NBTE has been considered as an important source for emboli, a potentially recognizable clinical entity (frequently associated with cancer, heart failure, or vascular thrombosis) and a step in the pathogenesis