The knowledge of these difficulties must not deter us from making the inquiry, so far as practicable, into the exact nature of the disease ; but it ought to lead us to embrace in our view the whole of the circumstances of each individual case. To these we especially look for guidancei in determining the very import ant question, whether we have to do with the results of inflam mation, or with a true or false hypertrophy of the organ, or with a malignant and necessarily fatal disease ; and we must place in a subordinate rank the suggestions that may be received from the locality or the sensible qualities of the tumor.
The forms which have been admitted into the table as being met with in the medical wards of the hospital are : (a) systio growths, (b) fungoid or encephaloid cancer, (c) scirrhus, (d) colloid cancer, (e) growths from bone.
a. In considering the relative frequency with which we en counter these several forms of morbid growth in different regions or organs, it may be remarked that cystic growths divide them selves into two classes, the acephalocyst, which is entirely ad ventitious, and the simple or compound cyst, which consists of an abnormal development of natural structure. We have already referred to the connection between the acephalocyst, or simple hydatid, and the echinococcus ; practically there is no advantage in discriminating cystic growths except in so far as the knowledge of the presence of fluid derived from its fluctuation leads to the evacuation of the contents. They all have this property in com mon, that their destructive tendency is limited to the organ in which they are situated, and they affect the general health no further than as the function of that organ is of importance, or their size interferes with the integrity and usefulness of surround ing structures. The hydatid is especially prone to infest the liver ; and it is there alone that its presence can be made out with the remotest degree of confidence during life :. of the other forms of cyst, those only claim any notice which are found in the mamnue and in the ovaries. Pathological anatomy, indeed, teaches us that other organs are liable to become the site of cystic growth, but I know of no test by which they can be brought under the province of diagnosis.
b. Fungoid or enceplialoid cancer is the form of malignant dis ease commonly found in the chest, whether it be attached to the pleura or the mediastinum. (in both of which it is sometimes a matter of doubt whether its first point of departure be not from bone), or whether it be developed from the intra-thoracic glands, or, as happens in rare instances, from the glands in the axilla. In
the abdomen, it is the character which cancerous growth generally presents in the liver, it is that which is always developed when its origin is in the deep-seated lumbar glands, and it forms the most numerous section of cancers of the uterus and vagina.
c. Scirrhus, again, exists, in the largest proportion of oases of cancer of the stomach ; it attacks the rectum, and in rarer cases, other portions of the alimentary canal : in all of these we rest our diagnosis chiefly on that which is known to be its constant result, partial occlusion of the passage, which is not unfrequently com bined with subsequent ulceration ; evidence proving this event is therefore very confirmatory. Scirrhns of the uterus and vagina is often spoken of, and no doubt exists in many instances : most commonly, however, it is combined with fungoid disease, and very often cases are 'called scirrhus which ought to be called fungus.
d. Colloid cancer seems most readily developed in the loose structure of the omentum and of the peritoneum generally ; and its existence can only be inferred from the fact of abdominal enlargement, which cannot otherwise be accounted for, coinciding with constitutional disturbance. This form of cancer, however, is the one in which cachexia is least marked ; and I must again repeat that there is the most important point in medical diagnosis when we speak of cancer. It is at least unwise to give an opinion implying the existence of cancer when the general indications do not point to something more than can be traced to local disorder; and while it is quite true that all internal growths are of serious import, because they are so little amenable to treatment, we must exercise great caution in attempting to analyze further, and say what is the exact character of the growth.
e. Growths from bone seldom come under the physician's notice, except when developed in the mediastinum, on the ribs, or on the bones of the pelvis: in these localities they are usually of a malig nant character; the slower growing enchondroma is less common in them than in the long bones of the extremities, and the same is true of the myeloid growths which have of late occupied the attention of surgeons.