NEOPLASMS. TUMORS OF THE INTESTINE IN SOLIPEDS.
Lipoma: sessile or polypoid, pediculated, strangulation, stenosis, size. Sarcoma: on bowel or peritoneum. Fibroma: flat or pediculated, obstruction, stenosis, degeneration, fatty, calcic. Myoma: hypertrophy of muscular coat, degeneration, stenosis. Myxoma: small translucent, oval, intestine mesentery. Carcinoma: extension from urocyst in horse, intestine, lymph glands, spleen, stomach, liver, mesentery, omentum. Epithelioma: colon, stomach. Cystoma: may contain sand or sclerostomata. Lymphadenoma: rectum, colon. Undetermined neoplasms. Causes: foreign bodies, microbes, constitutional, hereditary. Symptoms: tardy defecation, obstruction; in malignant, pallor, anæmia, emaciation; peritonitis, ascites; fœtid irregular stools, bloody, sloughs, rectal exploration. Treatment: surgical removal where possible, recovery by sloughing, laparotomy, useless in multiple or malignant tumors.
Tumors of the intestine are very varied in kind (lipoma, sarcoma, fibroma, myoma, myxoma, carcinoma, epithelioma, cystoma), and are found on all portions of the canal.
Lipoma or fatty tumor is most frequent in connection with the small intestine or rectum, and on the mucosa it may assume a pediculated or polypoid form and may more or less perfectly block the intestine. When situated under the peritoneal surface it is usually sessile and flattened apart from the mesentery, but if growing from the latter or at its connection with the bowel it tends to become pediculated, sometimes hanging at the end of a very long cord which may roll around a loop of intestine and strangle it. Similarly the sessile masses, as they increase press inward so as to diminish the calibre of the bowel and finally close it. They are often found no larger than a coat button, while in other cases they grow to enormous size (25 lbs. Vogt, 42 lbs. Semmer). Semmer’s case bound the cæcum and colon to the abdominal wall. The structure is essentially fatty tissue, though in some cases the fibrous stroma is more dense than in others.
Sarcoma. Small round cell tumors have been repeatedly found in connection with the intestine or mesentery. Baranski found one over 4 inches in length in the wall of the large intestine producing a serious constriction. Lucet found one of 18 lbs. weight and Mouquet one of 7 lbs. attached to the omentum. They are found to follow in certain cases the irritation and exudation of peritonitis.
Fibroma. Pediculated fibrous tumors have been found in the rectum of the horse and when large may threaten obstruction. They are usually of a loose fibrous texture, soft and elastic, and are often situated between the mucous and muscular coats. Quite frequently they are already in process of fatty or calcareous degeneration at particular points, the debris tending to fall into the intestine and be discharged with the fæces.
Myoma in the form of hypertrophy of the muscular coat of the bowel, the muscular fibres being increased in number and the wall further thickened by an intermixture of fibrous tissue, with areas of fatty degeneration. This may be confined to one side of the bowel and assume a spherical form, but it tends to contract the lumen until it is little more than half an inch in diameter. Mollereau records one case of myoma of the double colon which measured nearly a foot in diameter.
Myxoma. These are small, pale, translucent, round or oval neoplasms having a sparse network of fusiform cells and fibres, filled in the main with small round mucus corpuscles. They are not frequent in man and appear to be less so in the lower animals, but Friedberger and Mollereau have recorded two cases of myxoma in the intestines of the horse, and Chassereaud one case connected with the mesentery. In one case a mare passed such a tumor three inches long and nearly an inch in thickness. Chassereaud’s case caused torsion of the floating colon.
Carcinoma. Cadeac says it is not rare to see cancer spread from the urinary bladder to all the abdominal organs in the horse. Conté describes a case in the duodenum, Marty one on the pelvic flexure of the colon, Latour on the ileo-cæcal valve, Mario on the floor of the rectum, and Casper in the lymphatic glands of the spleen, stomach, liver, mesentery and omentum, the last showing a mass of 28 lbs.
Epithelioma. When in a growing neoplasm, epithelial cells are arranged not only on the surface, but also in the form of cylinders extending into the substance of the tissues the growth is looked upon as epithelioma. Morot records a growth of this kind on the horse’s colon, and which had grown to enormous dimensions. Röll also mentions it as occurring on the gastric and intestinal mucous membrane.
Cystoma. As seen in the horse these have usually been determined by the presence of foreign bodies. Redieux describes a cyst of the small intestine which enclosed 30 lbs. of sand. Charlot speaks of a cyst placed between the stomach and sternal arch of the double colon, furnished with a smooth serous lining. Vernant and the author have found on the walls of the cæcum and double colon small cysts, each communicating with the interior of the intestine by a narrow opening. Beside mucopurulent matter, these have often in our experience contained the sclerostomata or their larvæ.
Lymphadenoma. Wuth describes a case of obstruction of the rectum by an adenoid tumor as large as the closed fist, which induced a fatal hemorrhage. It was connected with the terminal part of the floating colon. Jobelot records another case.
Tumors of uncertain kinds. A large number of tumors are described in veterinary literature, the true nature of which has not been made out. If these could be successfully differentiated they would add to the above list materially, and other forms not referred to above.
Causes. The causes of these neoplasms are not always traceable. In the case of some an occasion may be found in the presence of an irritant, like worms, sand, gravel, oat seed, etc., found in their interior, in others like the carcinomata we may accept the presence of the protozoön of that disease, and in still others there is an unknown cause, perhaps constitutional or hereditary which predisposes to the new growth. This last cause was probably operative in producing the fatty neoplasm in the rectum of Pritchard’s fat Hereford heifer, seeing that her grandsire also died from a similar lesion.
Symptoms. These usually culminate in the classic symptoms of obstruction of the bowels, but there is sometimes a train of significant symptoms leading up to this climax. Thus in the malignant tumors in particular, though in some other forms as well, there is anæmia, pallor or yellowness of the mucosæ, weakness and emaciation. In other cases there are symptoms of peritonitis and ascites. In others there is obstinate constipation or diarrhœa, the excretions having a peculiar fœtid odor, often suggesting the decomposition of animal matter. They may be mixed with fresh blood, or sloughs from the surface of a tumor, or the whole tumor may be passed at once. Rectal exploration may be intercepted by a rigid stricture, by a tumor blocking the lumen, or a mass may be felt projecting in from one side. Aside from these the situation, form and size of the tumor can sometimes be felt through the flaccid walls of the rectum. In other cases the blocked and distended bowels may be felt, without the identification of a tumor as the cause.
Treatment. For tumors situated in the rectum, the removal by surgical measures (torsion, ecraseur, etc.) is indicated. If the tumor is simple a permanent cure may be hoped for; if malignant it is likely to recur. Tumors situated more anteriorly are usually desperate cases. Yet a certain number of pediculated tumors are detached spontaneously and discharged. In the absence of this, and when a tumor can be certainly diagnosed, there remains a resort to laparotomy, which in the horse is too often unsuccessful. If the tumor can be made out to be malignant and multiple it is useless to resort to removal.