CANCER, or Carcinoma (from Lat. cancer, Gr. καρκίνωμα, an eating ulcer), the name given to a class of morbid growths or tumours which occur in man, and also in most or all vertebrate animals. The term “malignant disease” is commonly used as synonymous with “cancer.” For the general pathology, &c., of tumours see [Tumour].
Cancer exists in various forms, which, although differing from each other in many points, have yet certain common characters to which they owe their special significance.
1. In structure such growths are composed of nucleated cells and free nuclei together with a milky fluid called cancer juice, all contained within a more or less dense fibrous stroma or framework.
2. They have no well-defined limits, and they involve all textures in their vicinity, while they also tend to spread by the lymphatics and veins, and to cause similar growths in distant parts or organs called “secondary cancerous growths.”
3. They are undergoing constant increase, and their progress is usually rapid.
4. Pain is a frequent symptom. When present it is generally of a severe and agonizing character, and together with the local effects of the disease and the resulting condition of ill health or “cachexia,” hastens the fatal termination to which all cancerous growths tend.
5. When such growths are removed by the surgeon they are apt to return either at the same or at some other part.
The chief varieties of cancer are Scirrhus or hard cancer, Encephaloid or soft cancer and Epithelial cancer.
Scirrhus is remarkable for its hardness, which is due to the large amount of its fibrous, and relatively small proportion of its cell elements. It is of comparatively slow growth, but it tends to spread and to ulcerate. Its most common seat by far is the female breast, though it sometimes affects internal organs.