Unexpected infant death attributable to cardiac tumor or cardiomyopathy. Immunohistochemical and electron microscopical findings in three cases.

The pathological findings, including immunohistochemical and electron microscopical findings, in three infants who died unexpectedly of cardiac tumor or cardiomyopathy are reported. The first was a 13-month-old boy with tuberous sclerosis and multiple rhabdomyomas of the heart, who presented with a postpartal cardiac murmur and moderate cardiomegaly. The further history was unknown. The rhabdomyoma nodules were composed of spider cells containing small amounts of desmin and myosin as well as isolated myofibrils. Microscopically small glioma nodules contained high amounts of GFAP. The second case, a boy 4 months of age, died of a large benign fibrous histiocytoma of the heart after an uneventful history. Tumor cells contained alpha-1-anti-chymotrypsin and lysozyme. The third case, a girl 2 months of age, died unexpectedly of histiocytoid cardiomyopathy. The affected cells contained fat droplets, glycogen granules, many leptomer myofibrils and small amounts of myosin and desmin.