LAUSR

CASE PRESENTATION F-FDG PET is a well-established functional imaging technique for diagnostic oncological imaging for a variety of malignancies and their systemic involvement. We present a 60-year-old man with retroperitoneal liposarcoma who underwent F-FDG PET/CT to determine any systemic involvement. Initial F-FDG transaxial PET (Figure 1A) and fused PET/CT (Figure 1B) images show faint heterogeneous uptake in the myocardium consistent with physiological uptake. After 5 years, follow-up F-FDG transaxial PET (Figure 1C) and fused PET/CT (Figure 1D) images show occasional small nodular faint uptake in the apex, with a maximal SUV of 2.44 (arrows in Figure 1C and D). After two years, follow-up F-FDG transaxial PET (Figure 1E) and fused PET/CT (Figure 1F) images demonstrate focal intense uptake in the apex, with a maximal SUV of 7.43 (arrows in Figure 1E and F). Transthoracic echocardiographic images in 2-chamber view at end-systole (Figure 2A) and end-diastole (Figure 2B) show apical hypertrophy and a spade-like shaped left ventricle cavity. Electrocardiogram (Figure 2C) shows atrial fibrillation rhythm and deep inverted T wave in II, III, aVF, and V3V6, which had not been observed at the time of the initial PET. According to these findings, he was diagnosed with apical hypertrophic cardiomyopathy. The increasing clinical utility of whole-body FFDG PET/CT for diagnosing the systemic involvement of malignancies may increase the detection of occasional abnormal F-FDG uptake in the myocardium. This may indicate the presence of cardiac tumors including metastasis or inflammatory diseases such as cardiac sarcoidosis. Previous studies indicated the usefulness of F-FDG PET in hypertrophic cardiomyopathy patients. Apical hypertrophic cardiomyopathy is a rare variant of hypertrophic cardiomyopathy. It is characterized by primary hypertrophy localized exclusively in the apex of the left ventricle. Yamamoto et al. also reported a patient with apical hypertrophic cardiomyopathy, with occasionally increased F-FDG uptake in the apex on whole-body F-FDG PET/CT. The present case demonstrated increasingly intense uptake in the apex on serial follow-up F-FDG PET/ CT imaging.