Sclerosing hemangioma of the lung: pathological study and enzyme immunoassay for estrogen and progesterone receptors.

Sclerosing hemangioma of the lung is a rare benign neoplasm of uncertain histogenesis. In this study, thirteen cases of sclerosing hemangiomas were analyzed by immunohistochemistry for various histochemical markers including surfactant apoprotein. The pale cells were shown to share several immunohistochemical markers with epithelial lining cells and were suggested to be immature cells differentiating toward epithelial lining cells. Electron microscopic study failed to characterize the exact nature of pale cells, but it disclosed the precise structure of large lamellar bodies, which are frequently present in the cystic spaces of sclerosing hemangioma. These large lamellar bodies had common morphological characteristics to lamellar inclusion bodies of type II pneumocytes or epithelial lining cells. Eight cases of sclerosing hemangioma obtained freshly at surgery had a quantitative analysis of estrogen and progesterone receptors performed by enzyme immunoassay. The value of estrogen receptors ranged from 0 to 7.8 fmol/mg protein. In addition to this quantitative analysis, the immunohistochemical study demonstrated estrogen receptors mainly in the pale cell nuclei of several sclerosing hemangiomas. Estrogen receptors may play an important role in growth, differentiation and surfactant production in the sclerosing hemangioma.