Cystic and Solid Tumours.—A great variety of swellings is met with in the scalp.
Sebaceous cysts or wens are of frequent occurrence, and have been described in Volume I.
A dermoid cyst is most commonly situated over the position of the anterior fontanelle, in the region of the occipital protuberance, or at the lateral angle of the orbit. As it frequently lies in a gap in the skull, it may be connected by a pedicle with the dura mater, and is liable to be mistaken for a meningocele.
Fig. 177.—Multiple Wens.
(Photograph lent by Sir George T. Beatson.)
Serous cysts are occasionally found in the occipital region, and are believed to be meningoceles that have become shut off from the interior of the skull before birth.
Adenomas originating in the sebaceous or sweat glands are sometimes multiple, of a purplish colour, and the skin covering them is thin and glistening. They show a tendency to ulcerate and fungate, giving rise to a fœtid discharge, and may be mistaken for epithelioma; they are also liable to become the seat of epithelioma. They are treated by excision.
Large, flat papillomas or warts may be single or multiple; they are of slow growth, and as they may also become the starting-point of epithelioma, they should be removed.