Page:Skin Diseases of Children.djvu/95

Rh be sometimes felt, corresponding in rhythm with the action of the heart. Ulceration of the central portion of the surface occasionally takes place, and from this cause or from some accidental injury severe hemorrhage may result. Gangrene may occur and produce a spontaneous cure.

Nævus cavernosus is a deep-seated form of angioma over which the raised skin may appear of normal hue or present a dull-bluish or venous appearance. The tumor is formed by

. 33.—Birthmark of unusual extent.

masses of dilated veins and arteries surrounded by firm connective tissue, which extends into the interior and forms vascular cavities communicating freely with the enlarged vessels. In some cases a number of these tumors, of varying size but of the same character, will extend along the surface of the skin like deep varices. They are usually soft, especially when of large size, and have a peculiar lobulated feeling when pressed beneath the fingers.