Sarcoidosis is a disease of unknown etiology characterized by nonnecrotizing granulomatous inflammation involving multiple organ systems. Typically affecting adults between the ages of 25 and 45 years, the annual incidence of sarcoidosis in the United States is 10 per 100,000. The highest rates are found in those of Northern European and African ancestry, with women at greater risk than men.[1–3] Although sarcoidosis may affect any organ, it is most commonly seen in the lungs and mediastinal lymph nodes, followed by the skin, eyes, and liver.[1,3] Cardiac involvement is noted in up to 7% of patients and may occur with or without involvement of other organs. Cardiac sarcoidosis is more frequently reported in Japanese as compared to Caucasian and African-American patients.
Cardiac sarcoidosis may clinically present with heart block, dysrhythmias, valvular dysfunction, heart failure secondary to dilated cardiomyopathy, or sudden cardiac death. Recently, subgroups of sarcoid patients with clinical symptomatology mimicking arrhythmogenic right ventricular cardiomyopathy (ARVC) have been identified.[6,7] However, most patients are asymptomatic, therefore autopsy studies show a higher percentage of cardiac involvement than noted clinically, ranging from 15% to 90%.[8–10] In the United States, sarcoidosis mortality rates range from 1% to 8%; up to 50% are attributed to cardiac involvement and 40% of these patients were clinically silent prior to death.[8–11] Eighty percent of sarcoid-related deaths in Japanese patients are related to cardiac causes.
Am J Clin Pathol. 2020;153(3):294-302. © 2020 American Society for Clinical Pathology