8.10: Small intestine

The small intestine of most domestic species is quite similar in function and histology. Structural and functional differences in specific regions of the small intestine impart differential functional capabilities to these segments. The small intestine is divided into three distinct segments, from oral to aboral: duodenum, jejunum, and ileum. The major functions of the small intestine are digestion, secretion, and absorption. The small intestinal mucosa has several anatomic adaptations that serve to create an immense surface area with which to digest and absorb nutrients. These include the plicae circulares (intestinal folds), villi, and microvilli.

THE CANADIAN MIEDICAL, ASSOCIATION JOU-RNAL [June 1935 cedure and the result obtaiined have been quite satisfactory, and we feel sure that the portion of kidney that remains will improve in function.
We have presented this case in order to show that what is commonly called "iincontinence' may-1) due to ail essential vitium of developmeint whieh is amenable to surgical control. REFERENCE  IN a previous article the writer dealt withi the subject of sarcoma of the intestine. In this paper it is proposed to continue the discussion of malignant tumours of the bowel, confining it to true primary carcinomata of the small intestine.
In reviewing the literature one finds that frequently, and even recently, discussions of carcinoma of the small intestine have included carcinoids and other tumours. For this reason it is difficult, if not impossible, to give accurate figures regarding the incidence of true earcinomata of the small intestine. That they are uncommon, however, is generally conceded. Ewing4 estimates that they comprise about 3 per cent of all intestinal carcinomata, and Brill, about 2.5 per cent. In the AMontreal General Hospital the figure is considerably lower. In a series of over 600 cases of intestinal carcinomata admitted during the past twenty-eight years, only 7 true carcinomata of the small intestine have been found. This is slightly over 1 per cent of all intestinal carcinomata. During the same period a number of carcinoids of the small intestine have been recorded, many of which were casual autopsy findings, and one case of primary carcinoma of the ampulla of Vater. Confirming our experience, Lynch,8 after reviewing the literature in 1933, concludes that the incidence as stated by Ewing and others is much too high. Kiefer and Lahey6 point out that these tumours are slightly more common than sarcomata. This also agrees with our statistics.
The age incidence of primary carcinoma of the small intestine is similar to that of car-* From the departments of Pathology and Surgery, Montreal General Hospital, Montreal. cinioma in geineral. The average age is stated by Rolleston and by Clark3 to be 46 years. The earliest age reported was 31/2+ years (Duncan), while Pr imrose'2 found a ease in a man 80 years of age. Carcinoma is more common in males than in females, in the proportion of 2 to 1. In our series there were, however, three males and fotur fenmales the average age was 45.8 years.

SYMPTOMIS
Clinically, the'se tumours fall roughly into two groups, those with symptoms of acute and those with symptoms of chronic obstruction.
Generallys speaking, the symptoms will be characteristic of either group, or of a combination of both. The detailed symptoms, however, will vary with the location, size anid character of the tumour. Consequently, there is no typical clinical historv. In the cases resulting in chronic obstructioin the earliest symptoms usually are vague abdominal discomfort, most frequently in the umbilical region, accompanied by indigestion, increasing constipation, eructations of gas, and gradual loss of appetite, weight and strength. After a varying length of time the discomfort changes to definite pain of a colicky type, and gradually increases in frequency and severity.
With this development, all other symptoms are exaggerated and vomiting may develop, especially if the tumour is situated in the proximal portion of the jejunum or duodenum. There may be some distension. Constipation may alternate with diarrhwia. A1elsena and hwmatemesis are both rare, but occult blood in the stools may be demonstrated early in the disease. Cachexia may l)ecome very marked. Symptoms of acute obstiru(ction may sup)ervene .t any time. These svmptoms are too well known to bear repetition.
The rule holds in these cases, as in other forms of obstruction, that the more proximal the lesion, the more acute and severe the symptoms. It may be mentioned here that occasionally intussuseeption may have been brought on by the rare polypoid types of primary carcinoma.

DIAGNOSIS
The diagnosis of carcinoma is rarely made prior to operation, even when it has been possible to make an x-ray examination after an opaque meal. In chronic cases numerous other conditions must be considered in the differential diagnosis, and these only serve to make an exact diagnosis more difficult. Among the principal conditions to be excluded are,-(1) peptic ulcer, (2) gall bladder disease, (3) chronic appendicitis, (4) functional gastro-intestinal disorders, (5) diseases or tumours of the large intestine, (6) inflammatory adhesions and developmental bands, (7) intestinal tuberculosis. Other rarer possibilities are (1) Meckel's diverticulum, (2) internal herniae, (3) obstruction by the superior mesenteric vein, (4) sarcomata and rare tumours. In our series of seven cases, two were admitted with acute obstructive symptoms, and one other might be grouped with these, though the attack had subsided before he entered the hospital. The remainder all had symptoms of chronic obstruetion. CLASSIFICATION There is no uniformity in the many clagsifications that have been suggested for these tumours. MIost of the classifications suggested include carcinoids and other tumours that are not carcinoma. Excluding these, the majority of primary carcinomas of the small intestine have been found to be adenocarcinomata, usually of the annular stenosing variety. This is in marked contrast to the longitudinal growth of the sarcomata, which show little tendency to stenose the lumen of the bowel. Occasionally, polypoid carcinomata have been found, usually in conjunction with a local or general polyposis. These tumours at times have led to intussusception. SITE The site of carcinoma of the small intestine is most frequently toward either end of the small intestine, that is, in either the proximal jejunum or the distal ileum. The duodenum is less frequently involved, and most rarely of all the middle portion of the small intestine. In fact, this latter area has been looked upon as enjoving a comparative immunity from carcinoma. In our series of 7 cases, 3 were in the distal third of the ileum, 2 in the proximal jejunum, 1 in the middle portion of the small intestine, and in 1 case the site is not recorded. There were a few cases of carcinoma in the region of the ampulla of Vater, but it has not been considered advisable to include any of these in this series, as their exact origin could not be determined.

PATHOLOGY
All degrees of malignancy according to Broder's classification have been met with. Necrosis, ulceration and various forms of degeneration, as colloid and mucoid, are quite common. Perforation has occurred not infrequentlv and is often followed by peritonitis. Metastases may occur in remote situations, such as bone, lungs, liver, etc., as well as locally in lymph nodes and mesentery. All 7 of our series were adenocarcinomata of the constricting type. Six of them showed metastases in the regional lymph nodes or mesenterv. Ulceration in varying degrees was present in 4. Extensive mucoid degeneration and necrosis was found in 1, and local areas of ulceration and necrosis in 2. Perforation of the bowel had occurred in 2 of our series, but in both instances this had been walled off by adhesions to the adjacent bowel or mesentery. In one of these cases a perforation had also occurred between the terminal ileum and coecum, near the ileo-eaecal valve. In the Department of Pathology of the Montreal General Hospital, the so-called carcinoids of the small intestine have, for quite a long time, been regarded as a special kind of tumour and have not been classed with the carcinomata. Masson,9 in a recent article, has demonstrated very clearly that these tumours, which were first described by Lubarsch in 1888, originate from the argentophile cells of Kultschitzsky in the crypts of Lieberkuhn, and have an intimate connection with the autonomic nervous 'system. They may, at times, contain large numbers of nerve fibres and are then called neuro-carcinoids. They do not resemble true carcinomata, either grossly or microscopically, and they seldom metastasize. Many of them are very small and only accidental findings. The larger ones, however, may bulge into the lumen of the bowel and cause symptoms, and, as in one of ouir cases, maay produce obstruction. Occasionally, carcinoids are multiple. The separation, in this hospital, of these tumours from the true carcinomata is responsible for the low percentage of true carciniomata of the small intestine in our records.
TREATAIEN T In discussing the treatment of primary carcinoma of the small intestine oine point should be stressed. Given a history of partial chronic obstruction of the small intestine which cannot be satisfactorily explained, carcinoma should be considered and an exploratory laparotomy performed. Mortality statistics in all forms of carcinomata emphasize the importance of early and radical operation. Treatment of the cases resulting in acute obstruction needs little discussion beyond emphasizing the necessity for regarding relief of the obstruetion as the prime consideration.

PROGNOSIS
The prognosis in carcinoma of the small bowel is, in general, not so good as that of carcinomata of the bowel elsewhere. The more proximal the tumour, the poorer the outlook. Six of our series are known to have died, while the fate of the seventh is not known.
Following are the records of seven cases of carcinoma of the small intestine, which occurred in the Montreal General Hospital between the years 1906 and 1934. They are given in detail in order that a general picture of the clinical signs and symptoms may be presented. Lafleur. The patient stated that she had lost some weight since the onset of symptoms. She remained under observation for a short time, when she developed severe abdominal colic, with nausea and vomiting. After a few hours the vomiting became of a faecal character, and she collapsed and was admitted to the hospital by ambulance.
On admission she had a temperature of 1010, a running pulse of 128, and was in a state of marked collapse. The abdomen moved freely with respiration and was not distended. There was no splinting of the muscles, and only slight general tenderness. No masses were felt, nor was there any dullness to percussion.
There was, however, evident visible peristalsis in the left iliac region. Four hours after the onset of the facal vomiting, a diagnosis of intestinal obstruction was made and she was operated on by Dr. G. Armstrong.
A median line incision below the umbilicus was made under local anaesthesia. On opening the abdomen a distended small bowel protruded. The site of obstruction was located low down in the pelvis on the left side. The small bowel was involved and this was liberated and brought into the wound. The area of obstruction was confined to one area which looked as if a "whip-cord" had been tied around it. This area was clamped above and below, and a lateral anastomosis done. The mesenteric glands did not appear to be enlarged. The patient failed to rally after the operation and died the same day. S-07-787). K.deP., a female, aged 56, gave the following history. About 9 months previous to her admission she had a sudden attack of severe colicky abdominal pain in the pit of the stomach, followed by nausea and vomiting. The attack passed off after a few hours and she felt well the next day. Three weeks later she had a similar attack of pain which continued at similar intervals for the next three months. Then the attacks gradually became more frequent so that during the last two months they occurred two to three times a week. The patient had always been constipated, but this condition became worse with the onset of the attacks. There was never any blood or mucus in the stools. The patient's weight fell from 130 to 90 lbs.
Examination on admission showed a moderate degree of emaciation and anaemia. The patient was slightly irrational at times, with morbid ideas. There was a moderate degree of general arteriosclerosis. The abdomen moved freely with respiration. There was neither tenderness nor splinting, but an "egg-sizedl" tumour was felt in the lower right quadrant. The heart and lungs showed no abnormality, and the urine was negative.
Operation.-A mid-line sub-umbilical incision was made. On opening the abdomen and examining the intestines a small hard mass was found in the mid portion of the small bowel. This mass -a tumour in the intestinal wall -had lead to an annular constriction about 1 inch in width. Proximal to this the bowel was dilated and the wall thickened for some distance. No glandular enlargements were noted. A resection and lateral anastomosis was done. Post-operative recovery was uneventful and the patient left the hospital in four weeks. She had had some persistent diarrhoea after her operation, and she died at home within a week of leaving the hospital. An autopsy was done at her home.
Pathological examination (No. A-07-145 and No. S-07-238).-Examination showed the lateral anastomosis to be quite patent. In the surrounding mucosa a number of recent ulcers were found. No organic metastases were found, but the regional lymph nodes were enlarged. Microscopic examination of the surgical specimen showed a typical adenocarcinoma of the ileum, with metastases in the regional lymph nodes.
CAsE 3 (M.G.H. No. S-09-26). R.S., a female, aged 46, had complained for two months of colicky abdominal pain after meals. She stated that they had been mild at first but had gradually grown worse. She felt as though something were trying to pass along the bowel but could not. At times the pains were accompanied by marked borborygmi and considerable belching of gas. Her appetite had fallen off, and she was at times afraid to eat for fear of pain. The bowels had become very eon-stipated. There was no history of blood in the stools, nor was there any nausea or vomiting. There was some loss of weight.
Examination showed a poorly nourished woman, somewhat anaemic. The abdomen did not move with respiration, and was tympanitic throughout. In the left side, at the level of the umbilicus, a small hard mass could be felt. It was about ''the size of a walnut'', slightly tender and movable.
Operatiom.-A left trans-rectus incision was made at the level of the umbilicus. On opening the abdomen there was a ring-like constriction in the distal third of the ileum. So tight was the constriction that the lumen of the bowel would scarcely admit the tip of a lead pencil. In the mesentery opposite this constriction a large mass of enlarged and matted lymph nodes was felt. The bowel proximal to the constriction was dilated and cedematous. Resection of the constricted bowel and a lateral anastomosis were done. No attempt was made to deal with the glandular mass. Post-operative recovery was uneventful and after leaving the hospital x-ray treatments were carried out.
Pathological examination (No. S-09-340) .-Examination of the resected portion of the small intestine showed an annular constricting tumour which had almost occluded the lumen. The lymph nodes in the adjacent mesentery were enlarged, hard. and matted together by adhesions. Microscopic examination showed a typical adenocarcinoma, with extensive metastases in the regional lymph nodes.
A year later the patient returned to the hospital, having developed recurrent severe colicky abdominal pain with some nausea and occasional vomiting. She had lost 10 lbs. in these months. Examination showed a large tumour mass in the left lower quadrant. An exploratory laparotomy showed a large growth in the small bowel near the previous anastomosis, with metastases in the mesentery, omentum and broad ligament. There was such marked matting together of the intestines that no anastomosis was attempted. The wound was closed and subsequently healed. The patient was discharged in a hopeless condition and subsequently died at her home. admitted with symptoms of acute intestinal obstruction of a few hours' duration. Examination showed a patient in moderate shock. The abdomen was distended and did not move with respiration. It was moderately tender and there was splinting throughout. No masses were felt.
Operation revealed an annular constricting tumour in the lower third of the small intestine, which had greatly narrowed the lumen of the bowel. The intestine proximal to the constriction was greatly dilated, congested and Tedematous, while distally the bowel was collapsed. Resection and lateral anastomosis was done. Post-operative recovery was stormy, but the patient left the hospital in good condition. There were no subsequent follow-up records of the case.
Pathological examination (No. S-11-490) .-Tlhe specimen consisted of a portion of small intestine involved by a tumour mass which narrowed the lumen so that it was the size of a "goose quill". The mass surrounded the lumen completely and was very firm. Microscopic examination showed a typical adenocarcinoma of the small intestine, with no evident metastases in the regional lymph nodes. CASE 5 (M.G.H. No. S-28-7458). R.P., a female, aged 26 Years, had had occasional attacks of colicky abdominal pain for a year. The pain, which was in the upper abdomen, usually passed off in a few hours without vomiting or nausea. For twenty-four hours previous to admission the colicky pain had been persistent and was accompanied by nausea and retching. The pain had shown a tendency to abate just before her admission.
Examination showed a fairly well nourished female. The abdomen moved with respiration, and there was no rigidity, tenderness ordullness. No masses could be felt. The heart and lungs were negative. Urinalysis, negative.
White cells, 6,000. A barium series was carried out. The stomach was large, dilated and atonic. The duodenum was somewhat dilated. The six-hour plate showed 75 per cent gastric retention, while the duodenum and the first part of the jejunum was dilated. The head of the meal had reached the ascending colon. The findings suggested some obstruction of the jejunum close to the duodeno-jejunal flexure, the exact nature of whicl was impossible to determine.
Operation was carried out through a right rectus incision. On opening the peritoneal cavity the stomach and duodenum were found to be greatly dilated. In the jejunum just beyond the ligament of Treitz there was a hard annular mass constricting the bowel and showing an area of ulceration on its peritoneal surface. A resection of the mass was done removing the adjacent seg-FIG. 1.-Case 5. Photograph of a drawing of the resected portion of jejunum showing the annular constriction of the lumen caused by the tumour. The proximity of the excision line on one side of the tumour was made necessary by its nearness to the duodenojejunal flexure. ment of mesentery. Owing to the mass being close to the duodeno-jejunal flexure only a short proximal stump of bowel remained and an end-to-end anastomosis was done. Post-operative recovery was uneventful.
Pathological examination (No. S-29-4).-The specimen consisted of a portion of small intestine, 10 cm. in length. Near one extremity was an encircling hard mass, 2.5 cm. wide. This mass infringed upon the lumen, narrowing it to 4.5 cm. Immediately proximal to it the circumference of the intestine was 7 cm. The serosa opposite the indurated mass showed a depressed circular ulcer, 1.5 by 0.5 cm. which involved the proximal half of the circumference of the intestine. In the mesenterv opposite the tumour a small area of induration was palpable. The mucosa was almost completely wanting over the tumour area. On section the tumour area varied from 0.5 to 1.2 cm. in thickness, and was pale, very hard and showed ulceration. It was intimately attached to the surrounding intestinal wall. The muscular coats proximal to the constricting tumour was greatly hyper-tropliied; the proximal margin of the growth was within 1.5 cm. of the line of excision.
Microscopic examination showed a typical adenocarcinoma with quite extensive metastatic deposits in the regional lymph nodes.
This patient was re-admitted in August, 1929, with recurrent symptoms of partial intestinal obstruction of several weeks' duration, and nmarked loss of weight. A 1age mass was felt in the left lower quadrant, extending down into the pelvis. There was no tenderness or splinting, and no fluid in the peritoneal cavity. A barium series showed a slight delay in the jejunum and an x-ray of the vertebral column was negative. The diagnosis of recurrent carcinoma was made, and the condition was considered inoperable. X-ray treatment was carried out, and for a time this seemed to bring about some improvement, but the patient finally succumbed to toxiemia and inanition. Years, was admitted with a llistory that about three weeks prior to admission he was suddenly seized with a severe attack of generalized abdominal colicky pain. He did not vomit, but the pain persisted and lie was confined to bed for the next ten days. During this time hiis appetite was very poor and his bowels very constipated. The pain then gradually subsided, but left a dull ache in the right lower quadrant. A diagnosis of acute appendicitis was made.
Examination showed a well developed and fairly well nourished white male. The abdomen moved freely on respiration. There was definite localized tenderness in the right lower quadrant and slight splinting of the right rectus muscle, but no riebound pain. On deep palpation there was a tender mass at the level of and just to the right of the umbilicus which was thouglht to be a perforated appendix wrapped in omentum. The general examination apart from the above was negative.
At operation the mass wlhich had been palpated was found to be a tumour of the jejunum, about 30 cImi. fronm the duodeno-jejunal flexure. This involved the whole circumference of the bowel and almost occluded its lumen. It also extended into the mesentery to its root, involving the regional lymph nodes. Owing to the proximity of this extension to the mesenteric artery, it was found impossible to do a complete excision of the tumour. About one metre of jejununi containing the tumour and as much as possible of the mesentery were riesected, and an end-to-end anastomosis done. No evidence of metastases could be found in the liver or any other organ.
Pathological examination (No. S-33-1 75) .-The specimen consisted of 18 cm. of the jejunum in the centre of which was a constricting tumour measuring 7 x (6 cm. and 4.5 cm. in thickness. It was pale and the mucosal surface was ulcerated and its borders heaped up. The peritoneum overlying was intact. In the adjoining mesentery there was one enlarged lymph node. Microscopic examination showed a typical adenocarcinoma extending through all the coats of the intestine excepting the serosa. Mitotic figures were abundant.
The patient made a good recovery from the operation. The wound became slightly infected. This rapidly subsided. He left the hospital in good condition, but within six months died from metastases. . J.N., a male, aged 58 years, had for almost a year lost strength, weight and appetite. Three months before his admission he took a vacation but this failed to improve his condition. He then consulted a physician who found his abdomen was tender and also that he had glycosuria. Under observation he developed obstinate constipation and finally was forced to resort to enemata for relief. On at least two occasions bright blood was noted in his stools. A barium enema, done in anothei lhospital, showed a tumour in the ileo-eecal region. It is interesting to note that this man lhad, for some time, had a periodic medical examination, but beyond the persistent finding of slight glycosuria for whiclihe had undergone dietary treatment, nothing was found. His motlher and fathler had both died of diabetes.
Examination showed a mioderate amount of wasting and anaemia. The abdomen was slightly distended, but moved freely and symmetrically witlh respiration. The right lower quadrant felt slightly more distended than it did elsewhere, but no definite masses could be made out. The liver and spleen were not enlarged. Rectal examination was negative. General examination slowed nothing of importance. Examination by time Department of Metabolism confirmed the presence of a mild chronic progressive diabetes. He was prepared for operation by the use of diet and insulin.
At operation a large mass, wllieh was considered malignant was found involving the terminal ileum and the caueuiii. A resection was done of .30 em. of the terimiinal ileum, together witlh the cecuim, ascending colon and a portion of the transverse colon. Time retroperitoneal space was carefully examined for lymplh nodes, but none wer.e found. The posterior peritoneum was then closed and a lateral anastomosis between time stumps of time terminal ileum and colon was done.
Pathological examination (No. S-33-1932).-The specimen consisted of 31 cm. of the temn-inal ileum and 56 clll. of the ascending and transverse colons, witl attached mesentei-y and oinenturu. Time ileo-ccal junction was involved in a firnm irregular mass, withl resulting deforiimity. On opening the bowel, tIme above mass was found to involve chiefly the (ir(umference of the lower end of the ileum. It had also extended into and involved the poster.iorv wall of the C'cuIll tlhIrouglhout an area 9 cm. ivide. The normal ileo-caecal orifice was intact and uninvolved, but the tumour lhad extended tlhrouglh the walls of the cacuni and terimlinal ileum and into the mesenteri-. The imiesenterv bor.dering the more proximatl portion of the ileum vwas intimately involved in the local extension of the tuinour. This liad resulted from time growth destroying a large part of the tissues that norumally separate tIme lumen of time ileum from the caeum. MicIroscopic examination showed a typical adenocamcinoma involving all coats of the cemcuim and ileum to a greater or lesser degIee. There weie scattered areas of mucoid degeneration and extensive aieas of necrosis, as well as superficial ulceration, on botlh mucosal and serosal surfaces of tIme bowel. Post-operatively, the patient developed a severe diarrhlmaa, a fiecal fistula, and persistent hiccougli. In spite of blood transfusions and supporting treatment lie died eight *lays after operation. An autopsy, (No. A-33-226), was done wlich slhowed that the anastoniosis lhad broken down, resulting in generalized peritonitis. There was also a bilateral terminal broncho-pneumonia. The pancreas showed extensive sclerosis of the islets of Langerhans. There was also marked arteriosclerosis of the aorta and kidneys.

SUMMARY
The subject of carcinoma of the intestine is discussed, and the literature reviewed and brought up to date. In addition 7  \VHILE studying the relation betweeni intestinal amebiasis and mouth infection in the tropics, I published a short report' in 1923, regarding a considerable number of patients who had amcebic dysentery and at the same time suffered from pyorrhaea alveolaris. In these patients amrebw closely resembling the Entameeba histolytica were.abundant in the diseased pockets of the gums. Though suclh amozbbe were found in the mouth in a large percentage of the cases of intestinal ameebiasis, we were unable to ascertain whether the infection of the intestinal tract preceded the mouth infection or vice versa. It was noteworthy that eneysted amcebe were found in the stools of a number of patients with pyorrhra alveolaris who showed no clinical symptoms of amwbiasis, suggesting that the condition, though actually existing, may be ignored by the patient.
With the invaluable assistance and interest of Doctor Delgado, Dental Surgeon, of Cartagena, Colombia, during the years 1923 to 1925, I had the opportunity of studying a large number of different infections of the mouth, especially pyorrhoea alveolaris. All the cases of pyorrhwea studied presented amawbw in the pockets of the gums, and in 50 per cent the amebea closely resembled the Entamceba histolytica, both in fresh and in stained preparations. Stools were examined from all these patients and in 75 per cent eneysted amwebw were found. Eveni though at the time of observatioin no intestinal disturbance was complained of, the patients were known to have suffered before or had suffered later fromn ameebic dysentery.
Cats fed with cultures of Amnoba gingivalis presented an attenuated form of dysentery. The am'vba isolated from the stools of the cats resembled closely the Entamneba histolytica. The intestines, of 2 out of the 20 cats in the experiment, showed lesions typical of those produced by the Entamaba histolytica. One of our staff drank some water containing a culture of Antabce gingivalis, in order to observe the pathological effect, if any, that the ameebaw may produce in the human intestine. Four weeks after she took the culture she started to complain of dysentery, but not so severe as we were accustomed to see in the histolytica type. Except bismuth nothing was given, as we were interested in producing a chronic infection. The dysentery disappeared for a period of six months, but encysted amccbx were continuously found in the stools. After several recurrences, the dysentery became so severe that the patient was forced to receive active treatment, after which it cleared up. Two years later, however.
she was operated on for an amabic abseess of the liver, and almost paid with her life for this experiment.
Should we consider Aimaba gingivalis a pre-