'So-called mesothelioma' of the atrioventricular node--immunohistochemical study

So-called mesothelioma of the atrioventricular node is a rare lesion and a cause of sudden, unexpected death. A case of congenital complete heart block accompanied by polyclonal immunoblastosis is presented. The histological features of our case are fundamentally similar to that of the cases previously reported. Immunohistochemical findings indicated that the tumor may have originated from aberrant epithelial or mesothelial tissue.