Ultrastructure of sclerosing hemangioma.

Specimens from 9 patients with the varying histopathologic patterns of sclerosing hemangioma were studied by electron microscopy. Not only were there numerous identifiable vascular spaces, but many of the cells had the ultrastructural characteristics of endothelial cells whether they were lining vascular spaces, forming organoid structures or were isolated. The Weibel-Palade bodies served as a marker for endothelial cells. They are rod-shaped, with a length up to 2 mu and a diameter up to .1 mu, and contain a tubular substructure, the diameter of the individual tubules being 150 [unk]. Our findings clearly support Gross and Wolbach's theory that this group of lesions is of endothelial origin.