Rapid Communication: A Case of Pulmonary Sclerosing Hemangioma --A Light Microscopic, Immunohistochemical and Electron Microscopic Study--

A case of pulmonary sclerosing heman- gioma was studied using light microscopic, immu- nohistochemical and electron microscopic methods. The cytoplasm of the sclerosing hemangioma cells was positive to the anti-lung surfactant apoprotein monoclonal antibody (PE-10). These cells included pale cells of the solid areas, cells covering papillary projections, and cells lining cleft-like spaces. Elec- tron microscopic study showed that the predominant cells included poorly-differentiated pneumocytes and normal Type 2 pneumocytes. We concluded that the sclerosing hemangioma was an epithelial tumor with differentiation towards Type 2 pneumocytes.