Endomyocardial disease and eosinophilia. Report of a case.

While an association between blood eosinophilia and endomyocardial disease has been recognized, the role of the eosinophil in the pathogenesis of the cardiac lesions remains uncertain. In a 69-year-old-man with large cell carcinoma of the lung, marked eosinophilia was stimulated by and progressed with the course of the neoplasm which was producing an eosinophil chemotactic factor. Peripheral blood eosinophils were vacuolated and degranulated while those in the bone marrow were morphologically normal. Clinical evidence of cardiac dysfunction developed one month prior to death. At autopsy, 12 months after the onset of symptoms, endomyocardial disease was present. There were numerous eosinophils in the damaged myocardium and surrounding the pulmonary neoplasm. In patients with endomyocardial disease and eosinophilia, the eosinophil may be directly cardiotoxic or a primary mediator of cardiac damage; therapeutic attempts to reduce the number of eosinophils might be benefit.