The two entities at the top of the histologic differential diagnosis for cardiac sarcoidosis are idiopathic granulomatous myocarditis and idiopathic giant cell myocarditis.
Idiopathic giant cell myocarditis is characterized by an infiltrate of eosinophils, lymphocytes, macrophages, and giant cells associated with myocyte necrosis.
A clinical and histopathologic comparison of cardiac sarcoidosis and idiopathic giant cell myocarditis.
Giant cell myocarditis is a rare condition that was initially described by Saltikow in 1905.
Furthermore, this patient's favorable clinical course may be in part related to the atypical histologic appearance for giant cell myocarditis, with a relative paucity of giant cells.