xuberant and rapidly
growing form of epithelial cancer, described by Hutchinson as the
_crateriform ulcer_, commences on the face as a small red pimple which
rapidly develops into an elevated mass shaped like a bee-hive, and
breaks down in the centre. Epithelioma may develop anywhere on the body
in relation to long-standing ulcers, especially that resulting from a
burn or from lupus; this form usually presents an exuberant outgrowth of
epidermis not unlike a cauliflower. An interesting example of
epithelioma has been described by Neve of Kashmir. The natives in that
province are in the habit of carrying a fire-basket suspended from the
waist, which often burns the skin and causes a chronic ulcer, and many
of these ulcers become the seat of epithelioma, due, in Neve's opinion,
to the actual contact of the sooty pan with the skin.

The term _trade epithelioma_ has been applied to that form met with in
those who follow certain occupations, such as paraffin workers and
chimney-sweeps. The most recent member of this group is the _X-ray
carcinoma_, which is met with in those who are constantly exposed to the
irritation of the X-rays; there is first a chronic dermatitis with warty
overgrowth of the surface epithelium, pigmentation, and the formation of
fissures and warts. The trade epithelioma varies a good deal in
malignancy, but it tends to cause death in the same manner as other
epitheliomas.

Epithelial cancer has also been observed in those who have taken arsenic
over long periods for medicinal purposes.

[Illustration: FIG. 102.--Rodent Cancer of Inner Canthus.]

#Rodent Cancer# (Rodent Ulcer).--This is a cancer originating in the
sweat glands or sebaceous follicles, or in the foetal residues of
cutaneous glands. The cells are small and closely packed together in
alveoli or in reticulated columns; cell nests are rare. It is remarkably
constant in its seat of origin, being nearly always located on the
lateral aspect of the nose or in the vicinity of the lower eyelid
(Fig. 102). It is rare on the trunk or limbs. It commences as a small
flattened nodule in the skin, the epidermis over it being stretched and
shining. The centre becomes depressed, while the margins extend in the
form of an elevated ridge. Sooner or later the epidermis gives way in
the centre, exposing a smooth raw surface devoid of granulations.

[Illustration: FIG. 103.--Rodent Cancer of fifteen years' duration,
which has destroyed the contents of the O