Diagnosis of cardiac sarcoidosis despite negative findings on serial late gadolinium enhancement with cardiac magnetic resonance imaging/18F-fluorodeoxyglucose positron emission tomography examinations.

We present a case of a 42-year-old Japanese man with ocular and pulmonary sarcoidosis who eventually led to a diagnosis with cardiac sarcoidosis (CS) through endomyocardial biopsy (EMB), despite negative findings on both late gadolinium enhancement with cardiac magnetic resonance (LGE-CMR) imaging and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). Cardiac sarcoidosis (CS) develops in only 5% of patients with systemic sarcoidosis. Previous studies have reported that CS was found in up to 50% of autopsy series with fatal sarcoidosis, implying that CS is frequently underdiagnosed with potentially life-threatening consequences. Therefore, the diagnostic accuracy and prognostic value of CS are important. Currently, LGE-CMR and FDG-PET play an important role in establishing a diagnosis of CS with high sensitivity. In the presented case, regardless of serial examinations with LGE-CMR and FDG-PET, confirmed diagnosis of CS could not be achieved; ultimately, a definitive diagnosis of CS was obtained through EMB. To the best of our knowledge, this is the first reported case showing the diagnosis of CS despite negative findings on serial LGE-CMR and FDG-PET examinations.