Somatostatin Receptor Scintigraphy Aiding the Exclusion of Cardiac Sarcoidosis in a Patient with Duodenal Neuroendocrine Tumor who Developed Complete Atrioventricular Block.

Cardiac sarcoidosis is a major cause of complete atrioventricular block. Although fluorodeoxyglucose-positron emission tomography (FDG PET/CT) is valuable for the diagnosis, inadequate fasting may result in a physiological myocardial uptake, making interpretation difficult. Somatostatin receptor scintigraphy (SRS), which does not require fasting, has been reported to detect myocardial inflammation in patients with DCM. We herein report the case of a 72-year-old man who developed complete atrioventricular block after surgery for a duodenal neuroendocrine tumor. In this patient, FDG PET/CT showed a marked cardiac uptake, while SRS findings suggested a low likelihood of cardiac sarcoidosis. In patients with malignancies and cardiovascular diseases, SRS may be useful for excluding cardiac sarcoidosis.