Cardiac myxomas. An immunohistochemical study using endothelial, histiocytic, and smooth-muscle cell markers.

Previous immunohistochemical studies of cardiac myxomas are few in number, limited in scope and, in part, discrepant. We studied the immunoreactivity of five cardiac myxomas for factor VIII-related antigen, Ulex europaeus agglutinin I, smooth-muscle myosin, alpha 1-antitrypsin, and alpha 1-antichymotrypsin. Positive staining was present in all five tumors with each cell marker used, but varied according to the area of tumor examined. The result of this study provides further evidence of the cellular heterogeneity in these tumors that probably originate by differentiation of multipotential mesenchymal cells.