[Syndrome of enlarged thymus gland in children with congenital heart defects].

Material of the study represents samples of the enlarged thymus of 40 children aged from 1 month to 3.5 years obtained during surgery on the open heart. A thymus enlargement in the majority of children with heart malformations was due to its reactive hyperplasia similar to the first stage of acute (accidental) involution or changes observed in the thymus in the "rebound" phenomenon. In some cases B-lymphocytic hyperplasia was observed which is considered as a sign of the autoimmune disturbances.