Cardiac sarcoidosis accompanied by a tumor-like blush on coronary angiography

A 71-year-old female was diagnosed with cardiac sarcoidosis by a history of complete atrioventricular block requiring pacemaker implantation and a focal thinning of basal interventricular septum (IVS) on echocardiography. Coronary angiography showed a tumor-like blush fed by septal branch of left anterior descending artery and right coronary artery concomitant with a coronary-to-right ventricle shunt. Echocardiography showed a low echoic mass at mid-IVS with an abnormal shunt flow into right ventricle. Fluorodeoxyglucose (FDG)-positron emission tomography (PET) showed an uptake at the corresponding site of mid-IVS. Eight months after the initiation of steroid therapy, FDG-PET showed no abnormal uptake at mid-IVS, suggesting decreased activity of cardiac sarcoidosis. We experienced a case of cardiac sarcoidosis with FDG uptake accompanied by a tumor-like blush at mid-IVS. The present case suggests the involvement of microvascular accumulation in the activity of cardiac sarcoidosis. <Learning objective: The detailed mechanism of granuloma formation in patients with sarcoidosis has not been clarified. Although the involvement of microvascular accumulation in the activity of extracardiac granuloma including lung and retina has been reported, the involvement in the activity of cardiac sarcoidosis remains to be elucidated. The present case with a tumor-like blush on coronary angiogram suggests the involvement of microvascular accumulation around the granuloma of cardiac sarcoidosis.>.