A case of pulmonary sclerosing hemangioma was studied using light microscopic, immunohistochemical 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. Electron 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.
Key words Pulmonary sclerosing hemangioma - Type 2 pneumocyte - Anti-lung surfactant apoprotein monoclonal antibody (PE-10)
A part of this study was presented at the 25th Annual Meeting of the Clinical Electron Microscopy Society of Japan, Matsumoto,
September 28–30, 1993.