High myocardial 18F-FDG uptake after chemotherapy in the presence of left ventricular dysfunction as well as 3-month later with no left ventricular dysfunction

Diffusely increased glucose metabolic activity in the right and left ventricles using 2-deoxy-2-(F-18) fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) and global left ventricular hypokinesia at echocardiography can be evident in acute myocarditis. But, there has been no case report that the ventricular 18F-FDG uptake remains unchanged even after recovery of ventricular hypokinesia. A 60-year-old female with primary pleural effusion lymphoma underwent echocardiography and electrocardiography due to fever and elevated cardiac marker after chemotherapy. The electrocardiography showed global hypokinesia suggesting heart failure and the managements were performed. After 20 days 18F-FDG PET/CT for assessing the extent of lymphoma demonstrated that newly appeared high 18F-FDG uptake in the myocardium suggesting pathologic lesions. To evaluate malignancy a cardiac biopsy was performed. Myocarditis was confirmed pathologically. Three months later, improved ventricular function was confirmed by echocardiography, but the metabolic activity in the ventricles was not decreased at follow-up 18F-FDG PET/CT.