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.