Lecture 23 diseases of alimentary system

Prof.Dr.
Khalil Hassan Zenad
Aljeboori
Copyrights©2017lAliraqiaUniversitylDentistrylPathologylProf.Dr.KhalilHassanZenadAljeboori.
Lecture 23
DISEASES OF ALIMENTARY
SYSTEM

Mainly are the followings:
1. Congenital malformation.
2. Diverticula.
3. Inflammation and ulceration.
4. Tumors.
5. Obstruction.
Intestinal tract diseases:

 Small intestine:
Meckel’s diverticulum:
It usually connected with ileum and may produce obstruction by the twisting of a loop of
bowel at this site due to fibrous band may attach the end of the diverticulum to
umbilicus, their mucosal lining resemble that of stomach, ileum,jejunum and duodenum.
 Appendix-no malformation or rare
 Large intestine: Congenital dilation of colon primary mega colon, marked dilation of
large intestine and hypertrophy of muscle fibers.
 Anus-rare except atresia
1.Congenital malformations:

may be false or true- the true diverticulum has all layers of the bowel in its
wall e.g.:
Congenital Meckel's diverticulum.
The false diverticulum are acquired herniation of mucosa through weak
place in musculature of the bowel, their wall contain only thin mucosa and
serosa, occur in both small and large intestine particularly in large intestine,
the common situations of diverticulum are esophagus duodenum and colon
(descending and sigmoid have a high incidence), its situated away from
mesentric attachment in contrast to the small intestine situation.
2. Diverticula of intestine:

Causes: 1. poisons 2. Infections
1- Poisons:
 Endogenous-uremia: in which hyperemia, edema, hemorrhage, necrosis,
diphtheritic changes, sloughing, ulcerations. The uremic ulcer occur more in ileum,
cecum, colon due to interference with blood circulation, irritation from excessive
ammonia due to increase urea excretion.
 Exogenous- heavy metals, mercury, and other corrosive may produce intense
hemorrhage, diphtheritic inflammation of bowel, ileum and colon most involved.
3.Inflammation and ulcerations:
It include large portions of tract, enteritis (intestine), ileitis, appendicitis, colitis, proctitis, colitis.

1. Cholera: caused by vibrio cholera organism infect intestinal tract through water and food induce Acute
catarrhal inflammation with marked reddening of mucosa, profuse diarrhea, flakes of white materials in watery
stool ( rise water stool) is characteristics, result in dehydration.
2. Typhoid fever and paratyphoid fever: is associated with enterocolitis accompanied bacteremia which lead to
generalized systemic disease. The infection occur through water, food, bacteria multiply in gastro intestinal tract,
pass through mucosa to payer's patches and then to blood.
The lesion benign as congestion, swelling of payer’s patches and solitary lymph follicles in the sub mucosa,
necrosis and ulceration extending longwise into mucosa causing perforation, hemorrhage.
In other organs:
Granulomatous lymphadenitis in mesenteric lymph node, lobular pneumonia, focal necrosis in liver,
splenomegaly and lymphoid hyperplasia of spleen, hypoplasia and leukopenia, sometimes osteomyelitis in bone
marrow, zenker’s degeneration of skeletal muscles, cholecystitis in gall bladder, pyelitis, cystitis of urinary tract,
similar lesion with paratyphoid but mild.
2- Infections:
Include coli-typhoid- dysentery, both gram negative bacilli, non-lactose fermenter and gram negative lactose
fermenter include E.coli. and related organism with low pathogenicity.

3. Bacillary dysentery:
Caused by Shigella dystenteriae which produce neurotoxins and endotoxins which injures the
intestine, it is spread by food and drink contaminated by a patient and carrier, it cause a diphtheric type
of inflammation, fibrinopurulent exudates, ulceration, sloughing of epithelia of intestine so abdominal
pain, pus and blood in stool, diarrhea stream or slight. The colon and ileum are mostly affected, the
lesion located in mucosa and sub mucosa. The toxic affect in brain degeneration of ganglion cells in
brain and spinal cord, peticheal hemorrhage.
4. Tuberculosis:
May complicate pulmonary T.B, through swallowing of infected materials or from contaminated milk or
via blood to intestine, ulceration are developed and ileum are usually affected, the ulcers are annular,
perforation so peritonitis may occur, scarring and stenosis due to tuberculous granuloma, the
mesenteric lymph node may be affected.

5. Chron’s disease, regional ileitis:
Chronic inflammatory process of unknown etiology affecting ileum resulting in thickening and
weakening of the intestinal wall through deposition of granulomatous tissue, obstruction and
perforation may result.
Microscopically:
Tuberculoma like picture with involvement of mesenteric lymph node associated with colic, pain,
diarrhea, fever for years, involve entire ileum and portion of colon may be involved with skip
alternating area in between, in this case bowel show thin, ballooned loops alternative with
thickened, obstructive loops, several perforation may be found- the tubercle like picture appear
microscopically granulomatous infiltration of bowel with lymphocytes, eosinophils and foreign body
giant cells without surgery the disease lead to peritonitis, abdominal abscess.

6. Chronic ulcerative colitis:
Manifested by diarrhea, melena, pyrexia, etiology unknown the rectum and sigmoid colon usually affected,
congestion, edema, necrosis, ulceration and hemorrhage, the ulcer enlarged and coalese together, psendopolypoidal
mass, fibrosis, thickening, stenosis and malignancy changes with early metastasis. Other complication include renal
tubular degeneration, cirrhosis, fatty change, pancreatitis.
7. Intestinal amebiasis:
Associated with amebic dystentery infection by ingested E. histolytica locally infect intestine, cause lysis of mucosal
lining of large intestine.
8. Intestinal bilharziasis:
Caused by Schistosoma mansoni. Infection of large intestine, especially rectum produce sandy patches, polyposis and
secondary infection, necrosis and hemorrhage of polyp and ulceration, the polyp microscopically showed granuloma
reaction around the ova so abdominal pain tenesmus, stool with blood and mucus with ova.
Other parasites include ankylostomiasis, ascariasis, teniasis, enterobius vermicularis and trichuriasis. Both associated
with catarrhal enteritis and bleeding spots and eosinophilia and anemia in case of ankylostomiasis.

Is usually caused by colon bacillus, E.Coli and other organisms, causing ulceration,
perforation with infiltration of neutrophils in mucosa and sub mucosa, muscular
layer and serosa, resulted in infarction, gangrene, and rupture of appendix. In
chronic cases of appendicitis , the organ is enlarged , firm, indurated, thick wall,
also evidence of ulceration, some time adhesions on surface and lumen replaced
by fibrous tissue(obliterative appendicitis) and even loss of lumen. Other features
of appendicitis called chronic lymphoid appendicitis with marked hyperplasia of
lymphoid follicles and lymphoid tissue causing thickening of mucosa and sub
mucosa.
Appendicitis:

• Various benign tumor such as fibroma, lipoma, myoma(leiomyoma) in small intestine.
• Lymphoma of ileum, colon, cecum.
• Carcinoma more common in colon and rectum in sigmoid colon 55%, rectum 70% transverse colon
20%, cecum and ascending colon 25% carcinoma may preceded by adenoma and adenomatous polyp,
carcinoma of rectum more common in male whereas carcinoma of colon more common in female
especially in 50 years, other tumor malignant melanoma, lymphoma are rare also carcinoid in
intestine is rare but common in appendix with moderately mature epith cells growing in syncytial
masses and separated by fibrous tissue band. These cells can be impregnated by silver and hence the
term argentaffin tumor. Also may affect small and large intestine, carcinoid or argentaffin tumor is
benign and 20% become malignant and metastasize to the mesenteric lymph node and liver.
• As for benign tumors leiomyoma, fibroma, lipoma, together with polypoid adenoma all these tumors
form benign growth single or multiple causing intestinal obstruction, may project into periton with
hemorrhage and diverticula.
• In case of polypoid adenoma also associated with obstruction with bleeding, these tumor may under
grow into malignant in 50% of cases and have hereditary predisposition. Polypoidal adenoma also
either sessile or pedenculated.
4.Tumors of intestine:

Acute obstruction:
1. Paralytic ileus: may develop following extensive peritonitis, trauma, mesenteric thrombosis and
severe toxic condition such as pneumonia, uremia, also follow injury to spinal cord. It caused by in
ability of intestinal muscle to propel the intestinal content. Paralytic ileus may complicate mechanical
obstruction.
2. Abdominal Hernia: are responsible for 60% of intestinal obstruction, loop of bowl are caught within
ring of hernia, so adhesion and blocking of blood circulation and venous stasis and edema of bowel,
unless surgically relieved ,infarction and necrosis of affected loop with perforation and peritonitis.
3. Intussusceptions: invagination of a portion of the wall of the intestine into the lumen immediately
distal to it. The ileocecal valve is mostly affected. Hypertrophy of lymphoid tissue, tumor which is
propelled forward by peristalitic wave is the etiology of the disorders.
5.Intestinal obstruction:

4. Volvulus: is twisting of intestine on it’s mesentery through an angle of 180 c0 or more. Sigmoid colon
and small intestine are common site. Abnormality of the adjacent mesentery is predisposing factor.
5. Foreign body obstruction: In which foreign body block the intestinal lumen, such as tumor, bolus of
undigested food, sometime impact gall stone, is the cause.
6. Hernia: abnormal protrusion of abdominal viscera outside the usual confines of abdominal wall may
through inguinal canal, femoral canal, umbilicus through weak scar of abdominal wound or through the
diaphragm, hernia become strangulated when there is a tight constriction of loop of bowel at the neck of
the sac, this constriction on veins and artery of hernia loop cause congestion, swelling, thrombosis and
infarction, gangrene.

Tumors adenocarcinoma may obstruct the lumen of intestinal tract by
invading it in an annular fashion, so the ring of constricting mass of
tumor imping on the lumen or protrude within lumen in polypoid
fashion. The pyloric region of stomach and sigmoid colon are generally
affected with the tumor adenocarcinoma.
Chronic obstruction:

Lecture 23 diseases of alimentary system

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