A case of idiopathic giant cell myocarditis with a past history of sarcoidosis.

A 70-year-old woman with back pain and breathlessness was referred to our hospital for suspected myocardial infarction. Coronary angiogram was normal and endomyocardial biopsy showed inflammatory cell infiltrates consisting of eosinophils and multinucleated giant cells. The clinical course was hemodynamically fulminant, but steroid therapy improved the cardiac function. Interestingly, this patient had a past history of sarcoidosis. We diagnosed this case with idiopathic giant cell myocarditis (IGCM) from its clinical course. However, whether IGCM and cardiac sarcoidosis belong to the same histological entity has been debated. This case is important with respect to the pathogenic association between these two disorders. <Learning objective: Both idiopathic giant cell myocarditis and cardiac sarcoidosis are known to show multinucleated giant cell infiltration in the myocardium histologically. In particular, idiopathic giant cell myocarditis is a severe and fulminant disease, making its early diagnosis and treatment important. Although it is difficult to diagnose these diseases, endomyocardial biopsy is useful to decide the treatment strategy in such disorders that may assume a fulminant course.>.