Bizarre nuclei of myocardial fibers in an infant with dilated cardiomyopathy. Light, electron-microscopic, and immunoperoxidase studies of a necropsy case.

The authors present the case of a 9-month-old child with clinical dilated cardiomyopathy that at necropsy showed myocardial cells with volumous, bizarre, and pleomorphic nuclei. These nuclear alterations were also found in other tissues. The myocardial ultrastructural studies revealed degenerative cytoplasmatic changes, nuclear membrane invaginations forming tubules, vesicles, and cytoplasmatic pseudoinclusions, and intranuclear vermicelar bodies, which all suggest virus-induced lesions. Although the ultrastructural studies and immunoperoxidase tests for virus identification were negative, the authors believe that a virus is most probably the agent of these alterations. This case seems to be the first reported on dilated cardiomyopathy with bizarre nuclear alterations in the myocardial fibers having strong evidence pointing to viral etiology.