Cancer, And Cancerous Ulcer, are of frequent occurrence in the skin. Cancerous degeneration and ulceration of subcutaneous tissues very frequently involve the skin over them, and cancers of the subcutaneous cellular tissue, and of glands imbedded in it, particularly of the mammae and lymphatic glands, usually become at an early period very closely connected with the cutis. But cancer also originates in the skin, presenting itself, according to my observations, under the forms of fibrous (scirrhous), and of medullary cancer.

A. The Form Which Fibrous Cancer Assumes

The Form Which Fibrous Cancer Assumes in the skin is that of a rounded, or rounded and tuberculated nodule; very often it is flattened, or even depressed beneath the surface of the skin, and then it lies in a sort of umbilical fossa. It is generally single, about the size of a hemp-seed, pea, or hazel-nut, firmly fixed, and as hard as cartilage: sometimes it is smooth and shining externally, and sometimes covered with a hard laminated crust of epidermis; and frequently it is somewhat darker than the skin around it. When examined closely, the outer strata of the nodule are occasionally found transparent. It occurs principally on the face, lips, and nose, but is occasionally found on other parts of the body: it is generally the primary cancerous growth, the first of a series of cancerous formations in different organs of the body. In some few cases it reaches a considerable size, growing out into a tuberous mass that projects beyond the skin.

B. Unlike fibrous cancer, the medullary kind is usually a secondary formation, and associated with large cancerous growths, which first appear just beneath the skin, or if they come from a greater distance involve the subcutaneous structures first, and then the skin itself: in either case it grows in the skin in isolated or confluent nodules near the primary mass. At other times it comes on in skin after cancer has been already localized in one, and still more when it exists in several organs; it then constitutes one part of an extensive, or it may be, of a general, production of cancer. The nodules which it forms are mostly numerous, and about the size of peas or hazel-nuts; they are scattered over large tracts of the body, especially over the trunk, and near similar growths in the subcutaneous cellular tissue. It is distinguished in the skin, as well as in that tissue, as a whitish or whitish-red growth, which is sometimes tolerably firm and lardaceo-medullary, and sometimes softer, looser, and resembling cerebral substance, or even diffluent like milk, and which grows to considerable size. It frequently corresponds with a character which may be possessed by the fundamental or primary growth, in also containing pigment; and in that case it constitutes cancer me-lanodes of the skin. The layer of skin which at first existed above the medullary nodule, becomes stretched, and sometimes is shining and transparent, sometimes rough from having lost its covering of epidermis: at a later period, as it is being perforated, it becomes moist, and furnishes the nodule with a cortical covering; and a remarkable villus-like development of its papillae takes place, which appears, from the result of observations upon chimney-sweeper's cancer, to occur in an especial degree in that disease. Sometimes the elementary particles of the disease are deposited in a pre-existing teleangiectasis, or, as the deposition takes place, there happens an excessive development of the vessels of the skin: the result, especially in the former case, is a cancerous structure of uncommon vascularity, which then receives the name of fungus hoematodes.

Chimney-sweeper's cancer, and Alibert's eburnated cancer of the skin, must be referred to as special varieties of the disease.

Chimney-sweeper's cancer appears to be of medullary nature. It almost always begins, as is well known, on the scrotum with a tolerably firm, small nodule, or a warty excrescence, which, after having existed for some time, becomes red, excoriated, moist, and covered with a cortex: the papillae beneath it enlarge considerably, and at length the whole becomes an ulcer with irregular, hard, raised edges. Fresh nodules form around it during its progress, and, by the ulceration of these, the original sore enlarges, for the most part superficially: the nodules at the same time become developed into fungous cauliflower excrescences, and at last the metamorphosis extends deeply. After infiltration and induration have taken place in the dartos and tunica vaginalis, and the latter has become adherent to the testicle, that gland itself ulcerates, while the adjoining lymphatic glands and the vas deferens degenerate quite up to the abdominal cavity.

The eburnated cutaneous cancer of Alibert is a diffused degeneration which occurs, without doubt, only as a secondary affection, the skin being destroyed in the degeneration of cancerous growths beneath it, at an advanced stage of the cancerous dyscrasia. Over a scirrhous subcutaneous cellular tissue, the cutis is stiff and immovable, white, glistening, and somewhat transparent, and the whole mass is uncommonly firm. Although the disease is very rarely observed with so marked a character as Alibert has seen, yet now and then an opportunity occurs of examining cancerous degenerations of the skin, which in some degree approach what Alibert has described as carcine eburnSe. It is quite uncertain, from its elementary structure, to what form of cancer it belongs, but, from the state of the disease with which it is connected, it should be the fibrous form.

From any of these cancerous growths a cancerous ulcer may be formed. Congestion and inflammation come on in and around the growth; and, while it becomes turgid, dark-colored, and vascular, and a fungous growth protrudes, it softens and splits, and, producing a cancerous sanies, breaks down. At the same time, new cancerous matter is deposited, either by infiltration or in nodules, in the tissue forming the margins and base of the principal ulcer. This metamorphosis of the cancer, as well as the softening of the secondary deposition in the ulcer, may run its course either with or without a fungous protrusion. The former is particularly characteristic of the ulcer of medullary disease; while, on the contrary, there are some remarkable cancerous ulcers, by which tissues are eroded not only without visible previous cancerous degeneration, but even without any considerable production of sanies. Ulcers of this kind do unquestionably often originate with one of the cancerous growths already mentioned; though not always, for they are sometimes developed secondarily from some injury or ulceration. They frequently produce extensive devastations, especially upon the face, and commonly attack and destroy all structures without distinction; for which reasons, as well as from their ungovernable nature, they are regarded as cancerous; but varied and accurate investigations of all their characters are still required.