Rodent ulcer. (Original.)
The development of cancer in lupus areas is now of sufficiently frequent occurrence to demand attention. Whether the epithelium which gives rise to it is to be accounted for by Cohnheim’s hypothesis, as having been cut off in the course of healing and become a cell rest to subsequently undergo malignant degeneration, is not yet settled. It has been suggested that curettage might cause fragments of epidermis to be loosened and then entangled in the cicatrix, and thus be responsible for subsequent malignant changes. When lupus thus degenerates it assumes usually the papillomatous form, which rarely involves lymph nodes, while the change which follows x-ray treatment often succeeds a hyperkeratosis and rapidly involves gland structure.
Rodent ulcer allies itself with the type of tubular epithelioma springing from the outer sheath of the hair follicle, sending out cylindrical processes which freely blend with one another. It is to be regarded as an equally malignant type of ulceration with other cancerous ulcers, and demands the same thorough and radical measures for its relief as do other forms of epithelioma. It is perhaps the most favorable one with which to deal, because of the usual freedom from involvement of deep lymphatics. No distinctive measures are necessary for its relief—only those which are thorough.
Carcinoma.
—Carcinoma is a tumor springing from preëxisting gland tissue, which it more or less closely resembles in type, save that the structural similarity is incomplete, the epithelial cells now collecting in irregular clusters, or filling the acini and obstructing the ducts, or bursting beyond the basement membrane and invading the surrounding tissues. They frequently so fill the ducts as to appear in columnar arrangement when seen under the microscope, and this has given rise to the use of a term so vague as to have no place in pathology—i. e., cylindroma. Carcinomas may arise from any of the secreting glands, but more commonly from some than from others. They have no capsules. They infiltrate the surrounding tissues, usually involve the lymphatics early, are liable to spread to the superficial tissues and to ulcerate, and to undergo various degenerative changes. Nearly all cancerous tumors abound in lymphatics, which will explain the rapidity with which the lymph nodes become infected, as well as the tendency to dissemination, which is characteristic of these growths. Dissemination leads to so-called secondary or metastatic growths, which may make their appearance in any organ or tissue, even in the bones, where they give rise to changes of texture that make spontaneous fracture easy. It is characteristic of carcinoma that the metastatic tumors which it may produce will reproduce almost perfectly the type of the primary tumor whence the embolic fragments which have produced them spring. The amount of dissemination varies exceedingly: it may even become so marked and widespread as to produce a condition analogous to that met with in miliary tuberculosis—miliary carcinosis. A similar condition, much more rare, is seen in dissemination of sarcoma, and is known as miliary sarcomatosis. A constantly spreading cancerous infiltration of the superficial tissues, which is noted most often after mammary cancer, is described under the form of cancer en cuirasse, or jacket or corset cancer. Instances will be seen in which this infiltration of the surrounding structures has extended nearly or even completely around the thorax. It gives rise to a brawny induration which is unyielding, and is studded here and there by nodules that tend to ulcerate, to fungate, and to bleed easily. It is perhaps the most hopeless form of cancerous disease.
The older writers have constituted two or three clinically distinct forms of carcinoma, based mainly upon the relative hardness or softness of the tumor and the invaded tissues. The term scirrhus is thus applied to a tumor in which connective tissue preponderates and epithelial cells are relatively deficient. On the other hand, the term encephaloid has been applied to a tumor in which the connective tissue seems barely sufficient to hold the mass together, while the epithelial cells are in vast preponderance. These are all tumors of the round epithelial-cell type, and these distinctions are of clinical interest, yet have no great pathological import, save that in a general way the greater the proportion of epithelial elements the sooner will life be terminated by destructive processes. In other words, the more the tumor may partake of the encephaloid type the worse the prognosis or the shorter the probable duration of life. Again, these tumors pursue a varying clinical course. In those tumors, particularly of the scirrhus type, where the connective tissue largely preponderates, there is often an eventual reduction in the size of the part involved, and such reduction of vascularity and of nutritive activity that the rate of growth is thereby perceptibly checked. The so-called atrophying cancers of the breast are the best examples of this type of cancerous disease. Here the volume of the gland is diminished rather than augmented, and the disease may last for a number of years. It is questionable whether it is well to operate.
The so-called colloid forms of cancer are simply the expression of pathological changes occurring in growths of more distinct type. Thus colloid softening may occur in any tumor in which cancer cells predominate, and the so-called colloid cancers of the peritoneum, the ovary, etc., are either examples of such alterations or are possibly endotheliomas arising in these locations. The term villous cancer, with other terms like it, should be expunged from all scientific literature, unless these terms are used in purely adjective and clinical sense, for they imply nothing accurate as to histological structure, and are often misleading and inaccurate.
Carcinoma is most common in the following regions:
In the breast it appears particularly in two forms: