Sclerosing hemangioma (histiocytoma, xanthoma) of the lung

I N UXISCKIISED masses occur in the lung that C possess fcatures similar to the lesion of the skin that is called "sclerosing heniangioma," "histiocytoma," or "xanthoma."They are not widely known within the lung, and, because some ha\e been misinterpreted as epithelial tumors, even of a malignant nature, the clinical, gloss, and microscopic features of se\en instances will be presented.Although it is probable that the growth of some of these lesions is self-limited in the lung, as in the skin, ne\ ertheless, for convenience, they will be called tumors.Considering the fact that the lung consists latgely of blood vessels, it is surprising that heniangiomas occur so rarely in this site.Cdf ernous arteriovenous communications and their functional consequences have been well described.12s22 Most observers have considered these to be congenital malformations rather than tumors, although proliferation of the component vessels, as well as expansion, appears to occur postnatally.Much less common are multiple communications of smaller intrapulmonary vessels.2.7 T h e more obviously neoplastic angiomas have been considered among the greatest rarities.de Lange and de Vries Robles described an infant who had large capillary angiomas involving both lungs.l w o problematical pulmonary lesions were repoi ted by Plaut under the title Hemangioendothelioma of the Lung.In one instance, in which the lesions were largely confined to the pulmonary arteries, it is possible that the process was one of exuberant recanalization of thrombi.I n the second instance, it still remains to be demonstrated that the proliferated