Thrombosed sinus of Valsalva aneurysm masquer ading as a cardiac tumour: a case report

Abstract

Abstract Background An aortic sinus of Valsalva aneurysm (SVA) often remains undiagnosed until it ruptures. An SVA filled with thrombus can be challenging to diagnose accurately. Case summary A 70-year-old man was admitted with a clinical diagnosis of well-tolerated complete atrioventricular block (AVB). Transthoracic echocardiography revealed a spherical mass (43 × 49 mm) at the interatrial septum. Enhanced computed tomography (CT) showed a well-defined, hollow, and non-enhanced mass suggesting a cardiac tumour. However, 18F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) showed no uptake in the mass. After implantation of a permanent pacemaker, anticoagulant therapy was started for paroxysmal atrial fibrillation. Two months later, follow-up evaluation by echocardiography and enhanced CT revealed an increase in size of the hollow interior cavity, suggesting thrombolysis by the anticoagulant. We diagnosed a non-coronary SVA filled with thrombus, which masqueraded as a cardiac tumour and may have caused complete AVB. Conclusions We describe a rare case of a giant thrombosed SVA masquerading as a cardiac tumour. Initial 18F-FDG PET/CT and serial imaging studies were helpful in distinguishing it from a cardiac tumour.