VASCULAR NAEVUS.
The vascular form of neevus results from an excessive development of vascular tissue in or beneath the skin, and presents a variety of clinical appearances. These may be conveniently classified as follows : 1, nsevus araneus ; 2, nsevus flammeus, or port-wine mark ; 3, naevus tuberosus ; and 4, nsevus cavernosus. Of the many descriptive names which have been more or less in use, these appear to best express the characteristic features of the four clinical varieties of vascular nsevus.
Naevus araneus consists of a small red spot, smooth or slightly elevated, from which several dilated capillaries radiate like the legs of a spider. It has sometimes been called " spider cancer,"' a name which is as alarming as it is inappropriate. It is not always congenital, but frequently appears in youth or adult life as the result of a prick, bruise, or other injury to the skin. On this account some writers class it under the head of telangiectasis or acquired vascular dilatation, assuming that the term nsevus signifies a birthmark and not merely a spot or blemish. It is most frequently noted upon the upper portion of the face, and upon a fair white skin may be quite conspicuous and annoying.
Naevus flammeus, birthmark or port-wine mark, as it is commonly called, usually appears as a smooth, red discoloration upon one side of the face. It varies greatly in size, often ex- tending down upon the neck and involving a considerable portion of the trunk. It varies also in color from a light pink to a deep purplish-red or even slate-colored hue. In its severe form the affected skin is elevated, the lip greatly swollen, and one side of the face may appear notably larger than the other. The dark surface of the skin may be dotted here and there in some cases by small vascular excrescences. At birth small, faint red marks may be noted, especially upon the lower portion of the occiput, which tend to disappear in later years, but the port-wine mark usually persists throughout life, either remaining unchanged or becoming more conspicuous. It has been claimed
