Early suspicion and recognition of hypersensitivity myocarditis, including findings on EMB, may lead to withdrawal of offending medications and administration of high-dose steroids.The hallmark histologic findings of hypersensitivity myocarditis include an interstitial infiltrate with prominent eosinophils with little myocyte necrosis (Fig. 7). Giant cell myocarditis, granulomatous myocarditis, or necrotizing eosinophilic myocarditis may mimic hypersensitivity myocarditis and EMB may be useful to distinguish these entities. Endomyocardial
Fig. 5. Giant cell myocarditis. Fig. 6. Cardiac sarcoidosis with solitary granuloma.