Nonbacterial Thrombotic Endocarditis of the Tricuspid Valve in a Male Patient with Antiphospholipid Syndrome

Valve vegetations in nonbacterial thrombotic endocarditis consist of fibrin and platelet aggregates and can be related to circulating immune complexes, such as in the case of antiphospholipid syndrome. In patients with primary antiphospholipid syndrome, echocardiographic studies have disclosed heart valve abnormalities in about a third of patients. Unusual associations between antiphospholipid syndrome and nonbacterial thrombotic endocarditis include presentation as an intracardiac mass compatible with a myxoma on imaging studies, as well as isolated involvement of the tricuspid valve. Both of these scenarios have been previously reported in female patients. This article presents the case of a 53-year-old Hispanic male with antiphospholipid syndrome who presented to the hospital with symptoms of heart failure and persistent right calf pain. An intracardiac mass attached to the anterior leaflet of the tricuspid valve was found through transthoracic echocardiography. Further imaging studies suggested the mass to be a myxoma and the patient underwent mass excision with tricuspid valve replacement. Pathology report of the surgical specimen was consistent with a diagnosis of nonbacterial thrombotic endocarditis. This case highlights the importance of considering nonbacterial thrombotic endocarditis as a key differential diagnosis in patients with concomitant antiphospholipid syndrome and intracardiac masses, as well as challenges encountered in diagnosis and management.