#Cavernous Angioma.#--This form of angioma consists of a series of large blood spaces which are usually derived from the dilatation of the capillaries of a subcutaneous nævus. The spaces come to communicate freely with one another by the disappearance of adjacent capillary walls. While the most common situation is in the subcutaneous tissue, a cavernous angioma is sometimes met with in internal organs. It may appear at any age from early youth to middle life, and is of slow growth and may become stationary. The swelling is rounded or oval, there is no pulsation or bruit, and the tumour is but slightly compressible. The treatment consists in dissecting it out. #Aneurysm by Anastomosis# is the name applied to a vascular tumour in which the arteries, veins, and capillaries are all involved. It is met with chiefly on the upper part of the trunk, the neck, and the scalp. It tends gradually to increase in size, and may, after many years, attain an enormous size. The tumour is ill-defined, and varies in consistence. It is pulsatile, and a systolic bruit or a "thrilling" murmur may be heard over it. The chief risk is hæmorrhage from injury or ulceration. [Illustration: FIG. 69.--Cirsoid Aneurysm of Forehead in a boy æt. 10. (Mr. J. W. Dowden's case.)] The _treatment_ is conducted on the same lines as for nævus. When electrolysis is employed, it should be directed towards the afferent vessels; and if it fails to arrest the flow through these, it is useless to persist with it. In some cases ligation of the afferent vessels has been successful. #Arterial Angioma# or #Cirsoid Aneurysm#.--This is composed of the enlarged branches of an arterial trunk. It originates in the smaller branches of an artery--usually the temporal--and may spread to the main trunk, and may even involve branches of other trunks with which the affected artery anastomoses. The condition is probably congenital in origin, though its appearance is frequently preceded by an injury. It almost invariably occurs in the scalp, and is usually met with in adolescent young adults. The affected vessels slowly increase in size, and become tortuous, with narrowings and dilatations here and there. Grooves and gutters are frequently found in the bone underlying the dilated vessels. There is a constant loud bruit in the tumour, which greatly troubles the patient and may interfere with sleep. There is no tendency either to natural cure or to rupture, but severe and even fatal hæmorrhage may follow a wound of the dilated vessels. [Illustration: FIG. 70.--Cirsoid Aneurysm of Orbit and Face, which developed after a blow on the Orbit with a cricket ball. (From a photograph lent by Sir Montagu Cotterill.)]