TUMORS (ante). The frequency of the occurrence of tumors, the great variety of them, and their various relations to the constitutional condition of the subject in which they are developed, make them of great importance, not only to the surgeon, but to all who are liable to be afflicted with them, and a more or less general knowledge of them should constitute a part of the education of every intelligent person. According to Dr. John Hunter (172S-1793, q.v.), a tumor is a "circumscribed substance produced by disease, and different in its nature and consistence from the surrounding part," and this general definition by a master-mind, although not strictly correct in the light modern pathology, is sufficient for our purpose. It may be well to add what has been proposed by one of the first of modern surgeons as an amendment, if for no other purpose than to show how little more can be added. "By a tumor may alSo be meant a more or less circumscribed mass, growing in some tissue or organ of the body, And dependent on a morbid excess of, or deviation from, the nutrition of the part." Tumors may be considered under two heads, viz., local hypertrophies, or outgrowths of the normal structure of the part, and of new formations presenting structural characters differing more or less from those of the parts around. The tumor thus formed grows by an inherent force of its own, without regard to the growth of the rest of the system, obeying, however, the general laws of growth which govern the organism in which they are developed.
A classification of tumors may be made from their anatomical structure, or from their vital and clinical characters. As stated in the preceding article, surgeons have for a long time divided tumors into malignant and non-malignant, but this division is not scientifically exact. Some tumors, as cancers, are always essentially malignant, and others are always benign, as certain cysts; but there are many that are usually benign or non-malignant, which, however, from causes yet unknown may take on malignant characters. Such are termed semi-malignant. Non-malignant tumors are local in their development, and are often described as having no hereditary connection. This, how ever, is frequently not so, as it is well known that cystic tumors, particularly of the scalp, arc known by common observation to be often hereditary. But notwithstanding they may be hereditary they are properly considered as local, because the constitution of the individual does not appear to be affected any more than where other peculiarities, such as double fingers and moles, are inherited.
From these growths malignant tumors have a wide difference. They are usually characterized by great luxuriance of development of a rather low character, a luxuriance termed vegetative, and are very liable to undergo, especially in their central parts, degeneration, ulceration, and gangrene. They represent a very great departure from the normal nutrition of the part, and as a rule indicate a fault. although it may be lint
little manifested outwardly, in the general nutrition of the body. Malignant tumors are often called heteromorphous, and this is true to a certain extent:but not so far as to signify that the new product is formed entirely on a new type, for the doctrine of Virchow, that "the same types of anatomical structures exist in new formations as are found in the body generally" is not disputed by the majority of pathologists. Briefly stated, the following are the principal signs in malignant tumors: It is at first small and usually with a distinct outline. -There is a constant tendency to extension by local Infiltration into the adjoining parts, by absorption, by incorporation into their substance, and by deposit of the new elements in their place, and this process is continuous; often very slowly, as in hard cancer of the breast, but in many cases, in certain situations, rapidly, as in soft cancer, the rapidity being usually the measure of the malignancy. The extent of the growth is unlimited, that is to say, it may attain any size consistent with the life of the subject; but when a certain extent is reached, depending ou the constitution of the patient, the central parts undergo fatty degeneration, and when this degeneration reaches the surface there is rapid sloughing or ulceration toward the center, causing profuse discharges which are usually very offensive, and often accom panied by hemorrhage. After a time, which varies considerably, the lymphatic glands which lie in the course of the lymphatic circulation, become enlarged and hardened in consequence either of a deposit of morbid elements, or from congestion of the glandular structure produced by a morbid condition of the fluids which pass through them. This. affection of the glandular system constitutes what is called the secondary form of the disease, in contradistinction to the primary tumor. This lymphatic coinplication may occur before the skin is affected, but almost invariably soon after that occurrence, and the pathological condition of the glands as revealed by the microscope are the same as that of the primary tumor. After the lymphatics are affected the internal organs, particularly the lungs and the liver, become the seat of secondary deposits, which, how ever, may differ somewhat in character from the primary tumor, and these deposits then become the foci of further development of the elements of the disease, which have an increased rapidity of growth; in other words, an increased malignancy. After the lymphatic glands are affected constitutional symptoms appear, such as sallowness, disturbance of digestion, wasting of the body, and general anaemia. Most malignant tumors are cancerous, but not always, although cancers are always malignant. Other malignant tumors are sarcomas.