the scalp.
_Lupus_ rarely originates on the scalp, although it may spread thither
from the face. _Syphilitic_ lesions are common and present the same
characters as elsewhere. Gummata may develop in the soft parts, but
more commonly they take origin in the pericranium or bone. _Eczema
capitis_ is of surgical importance only in so far as it often forms
the starting-point of infection of lymph glands by pyogenic and other
organisms.

#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.

[Illustration: 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 foetid 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.

[Illustration: FIG. 178.--Adenoma of Scalp.]

The _plexiform neuroma_ forms a loose soft tumour situated in the
course of one or more branches of the trigeminal nerve, especially
the supra-orbital branch. In its most aggravated form the tumour hangs
over the face or neck in large pendulous masses, and is described as a
_pachydermatocele_ (V. Mott).

A _sarcoma_ usually has its origin in the bones of the skull, and only
implicates the scalp secondarily.

_Epithelioma_ of the scalp may originate in relation to a wart, an
ulcerated wen or sebaceous adenoma, or the cicatrix of a burn. It may
affect comparatively young persons, may spread over a wide area, or
pass deeply and involve the bone. Free and early removal i