Löeffler endomyocarditis: a clinical presentation as right ventricular tumor.

A four-year-old girl presented with an apical mass of the right ventricle, pulmonary embolism and hypereosinophilia, and was shown to be infected with Toxocara canis. Cardiac involvement was represented by endomyocardial fibrosis, mainly at the apex of the right ventricle, mural thrombi and tricuspid regurgitation. Hypereosinophilia appears to be the head point at the basis of multiple organ damage in Löeffler endomyocarditis. The disease mechanism proposed is the eosinophilic production of peroxidases, which are cytotoxic when released in large amounts into the blood flow. Treatment is based on etiologic and corticosteroid therapy (prednisolone 1-2 mg/kg/day); surgical therapy is indicated in the end stages of the pathologic process.