Patho 27 - Flashcards
definition of the typhoid fever
Systemic infective disease of the small intestine & other organs,
caused by Salmonella typhi
Route of infection by the salmonella typhi
Ingestion of contaminated water or food
Incubation period of typhi
2 week. Disease: 5 weeks
Pathogenesis of typhoid fever
- Organisms are resistant to gastric acid; they invade the small intestinal mucosa and are subsequently engulfed by macrophages which go to Peyer’s patches /solitary follicles.
- The organism proliferate, reach the lymphatics then the blood causingbacteremia.
- The organisms are finally taken by RECs in liver, spleen and bone marrow were they multiply inside it. The REC’s undergo necrosis and the released organisms disseminate widely causing septicemia.
- Disease manifestation start in small intestine and then extra intestinal as spleen, bone marrow, gall bladder & other organs.
pathological features of the typhoid fever
- Peyer’s patches in the terminal ileum are enlarged and swollen. The overlying mucosa is shed leaving oval ulcers oriented along the long axix of the ileum..
- The spleen is enlarge soft and red, and shows prominent hyperplasia of phagocytic cells.
Gross “ peyer patches enlarged, oval ulcers , spleen enlarged
Complications of the typhoid fever
- Intestinal hemorrhage
- Perforation leading to septic peritonitis.
- Toxemia leading to heart failure.
- Bronchopneumonia
- Cholecystitis and development of carrier state.
- Typhoid osteomyelitis, localized periostitis develops after months or years.
- Meningitis encephalitis, pyelonephritis
Definition of the Dysentry
Inflammation of large intestine characterized by
diarrhea, tenesmus, mucous & blood in the stools
the types of dysentry
1) bacillary dysentry caused by shigella colitis
2) amoebic dysentry caused by enatameba histolytica
defintion of bacillary dysentry
Acute pseudomembranous inflammation of the colon due to infection by exotoxin producing Shigella organisms (a non-encapsulated Gram-negative bacillius).
route in infection of shigella colitis
fecal-oral rout
complications of Bacillary Dysentry
- Local
1- Hemorrhage
2- Perforation:
3- Rectal prolapse from frequent motions & straining.
4- Intussusception due to frequent motions with abnormal peristalsis.
5- Healing by fibrosis with stricture formation. - General toxic manifestation: Myocarditis, arthritis, peripheral neuritis.
Clinical Picture of bacillary dysentry
§ Dysentery; severe: diarrhea, tenesmus, blood & mucus..
§ Fever is high. & stool culture is +ve.
Pathological features of the bacillary dysentry
The large intestinal mucosa is diffusely inflamed, congested, edematous with patches of dirty greyish yellow pseudomembrane.
Shallow bleeding ulcers exist in between (areas where the pseudo-membrane has fallen off).
gross of Amoebic Dysentery
- Amebic colitis usually affects the cecum and ascending colon
followed by the rectum then sigmoid colon. - Multiple, small flask shaped ulcers
i.e. more destruction in submucosa than mucosa.
The ulcers have deep edges, necrotic floor & a base formed of the muscle layer. - The mucosa in-between the ulcers is healthy.
Defintion of Amoebic Dysentery
Infection of large intestine by Entameba histolytica parasite
microscopic picture of amoebic dysentery
- The edges and floor of the ulcers contains amoebae, which appear as rounded bodies surrounded by clear zones (due to lysis by the proteolytic enzymes of the amoeba).
- Chronically inflamed granulation tissue & fibrosis.
Complications of amoebic dysentery
1- Hemorrhage.
2- Perforation.
3- Rectal prolapse from frequent motions & straining.
4- Intussusception due to frequent motions with abnormal peristalsis.
5- Healing by fibrosis with stricture formation.
6- Chronic carrier.
7- Amoeboma:
© amoebic granuloma forming a mass in the wall which may be mistaken for a malignant tumor.
8- Spread of infection
- Direct: perianal fistula or ulcer.
- Blood: liver amoebic abscess.
Lung amoebic abscess.
cause of Antibiotic associated colitis
due to suppression of normal flora and
overgrowth of Clostridium difficile which causes a widespread toxic mucosal injury
pathological feature of Antibiotic associated colitis
The colon shows pseudomembranous colitis
definition of ulcerative colitis
Chronic disorder with repeated acute attacks of abdominal pain, diarrhea,& bleeding followed by periods of remission.
Gross of ulcerative colitits
It involves the rectum and extends proximally in a retrograde fashion to involve the entire colon.
1) Rectosigmoid most commonly affected by multiple superficial, small irregular ulcers.
2) Pseudopolyps which are small elevations formed of regenerating mucosa and granulation tissue.
3) Fibrosis in prolonged disease.
clinical picture of ulcerative colitis
pain, diarrhea,& bleeding followed by periods of remission
other name of ulcerative colitis
ulcerative procto colitis (procto=rectum)
small elevations formed of regenerating mucosa and granulation tissue and related to?
Pseudopolyps related to ulcerative colitis
microcopic picture of ulcerative colitis
- Active phase:
1- Mucosal ulcers. Inflammation is limited to mucosa and submucosa.
2- Diffuse infiltration by acute and chronic inflammatory cells with crypt abscess formation (aggregates of polymorphs in the lumen of distended crypts).
3- Degenerative changes in the surface epithelium with depletion of their mucin content and loss of goblet cells
4- Severe mucosal edema, congestion & focal hemorrhages.
5- No granuloma - Chronic phase:
1- Mucosal crypt distortion
(important in diagnosis when the inflammatory features have subsided)
2- Mucosal atrophy with submucosal fibrosis
3- Epithelial dysplasia in long standing conditions (premalignant)
microcopic picture of active phase of ulcerative colitis
Active phase:
1- Mucosal ulcers. Inflammation is limited to mucosa and submucosa.
2- Diffuse infiltration by acute and chronic inflammatory cells with crypt abscess formation (aggregates of polymorphs in the lumen of distended crypts).
3- Degenerative changes in the surface epithelium with depletion of their mucin content and loss of goblet cells
4- Severe mucosal edema, congestion & focal hemorrhages.
5- No granuloma
microcopic picture of chronic phase of ulcerative colitis
Chronic phase:
1- Mucosal crypt distortion
(important in diagnosis when the inflammatory features have subsided)
2- Mucosal atrophy with submucosal fibrosis
3- Epithelial dysplasia in long standing conditions (premalignant)
complications of ulcerative colitis
1- Hemorrhage.
2- Perforation &septic peritonitis.
3- Dysplasia & adenocarcinoma.
4- Amyloidosis.
5- Liver damage in the form of fatty change or biliary cirrhosis.
definition of chron’s disease
Idiopathic chronic inflammation of terminal ileum and other areas of the gastrointestinal tract
other name of chron’s disease
REGIONAL ILEITIS
gross of chron’s disease
§ Skip lesions (separate) with inflamed serosa and adherent creeping mesenteric fat; the bowel wall is thick and often strictured.
§ Early aphthous ulcers which may progress and coalesce into elongated ulcers along the axis of the bowel (serpentine ulcers).
§ Cobblestone appearance of the mucosa (diseased tissue appears depressed below the level of normal mucosa).
§ Deep fissures, fistula tracts and fibrosis
serpentine ulcers related to serpentine ulcers related to
CROHN’S DISEASE
cobblestone appearance of the mucosa related to
CROHN’S DISEASE
complication of chrons disease
1- Hemorrhage.
2- Malabsorption.
3- Fistulae & healing by fibrosis with strictures
4- 2ry amyloidosis
Microscopic of chron’s disease
- Segmental Inflammation and ulceration rich in
neutrophils affecting the whole thickness of
the wall (transmural inflammation). - Non caseating granulomas of epitheloid cells &
giant cells , is a hallmark of Crohn’s disease in 35% of cases. - Fibrosis.
definition of DIVERTICULAR DISEASE OF THE COLON
Diverticulae are acquired herniations of mucosa and submucosa into the wall of the intestine
predisposing factors of DIVERTICULAR DISEASE OF THE COLON
- are weakness in the intestinal wall due to senility & increased intracolonoic pressure from chronic constipation and deficiency of fiber in the diet.
pathological features of DIVERTICULAR DISEASE OF THE COLON
- They are most common in the sigmoid colon.
- They are usually multiple.
- The pouches are formed of mucosa & submucosa only.
- They protrude outwards through weak spots in the muscle layer on the mesenteric border (where the mesentery is penetrated by arteris, between the taenia coli).
complication of DIVERTICULAR DISEASE OF THE COLON
1- Stasis leading to 2ry infection causing diverticulitis or abscess.
2- Diverticulitis may
- Heal by fibrosis with stricture formation.
- Perforate leading to septic peritonitis.
- Lead to a fistula between 2 loops.
3- Hemorrhage & bleeding per rectum.
definition of appendix
Acute inflammation of the appendix, which may be catarrhal or suppurative
causative oragnism of appendix
Staphylococci, E. coli
route on infection that cause appendix
from intestinal lumen
predisposing factors that cause appendix
Obstruction with:
© Fecolith (hard stool pellets)
© Food residues (seeds)
© Lymphoid hyperplasia (viral infections, children)
© Presence of a carcinoid tumor.
pathogenesis of appendix
- Acute inflammation starts in the mucosa following a breach in the epithelium which permits infection from the gut flora.
First, there is mucosal ulceration and exudation of polymorphs and fibrin in the lumen. The inflammation spreads to involve all the layers of the appendix, resulting in congestion, edema and diffuse infiltration by polymorphs. - The build up of fluid exudate within the wall increases tissue pressure, together with toxic damage to blood vessels and thrombosis cause ischemia and the appendix can become gangrenous and perforate.
obstruction»catarrhal inflammation»mucosal ulceration»all layers of Appendix affected» gangrene
complication of appendix
- Perforation or rupture with septic peritonitis may progress to fatal septicemia.
- Gangrene.
- Appendicular mass (omentum tries to wall off local spread into the peritoneum
leading to abscess formation). - Portal pyemia from septic thrombophlebitis of appendicular vein.
- Chronicity: Chronic appendicitis
- Mucocele of appendix: Complete obstruction of appendix lumen at one point
following healing result in distention of appendix with mucus forming a
mucocele. - Pus formation with complete obstruction forms empyema (Bag full of pus)
what are the neoplastic polyps of the colon?
Adenomas:
- Tubular adenoma (adenomatous polyp).
- Villous adenoma (papillary adenoma).
- Tubulo-villous adenoma.
what are the non-neoplastic polyps of the colon?
1- Bilharzial polyps
2- Hyperplastic Polyps
3- Pseudopolyps
4- Hamartomatous Polyps
* Juvenile polyps
* Peutz-Jeghers Syndrome
gross of tubular adenoma?
precancerous, small and pedunculated
other name of tubular adenoma?
adenomatous polyp
Gross of villous adenoma
highly precancerous. Large and sessile.
Covered by villi
other name of villous adenoma
papillary adenoma
pseudopolyps are related to?
ulcerative colitis
gross of hyperplastic polyps of colon?
Small sessile polyps, have no malignant potential
Small sessile polyps of colon, have no malignant potential
Hyperplastic Polyps
polyps of colon common in children
Hamartomatous Juvenile polyps
gross of pseudopolyps?
small elevations of regenerating epithelium and
granulation tissue
polyps of colon related to extraintestinal manifestation
Peutz-Jeghers Syndrome (hamartomatous polyps)
types of hamartomatous polyps
Juvenile polyps
Peutz-Jeghers Syndrome
what polyps
The polyps consist of cystically dilated hyperplastic
mucous glands filled with retained secretion
juvenile polyps
gross of juvenile polyps
The polyps consist of cystically dilated hyperplastic mucous glands filled with retained secretion
enumerate colonic polyps?
1- Bilharzial polyps.
2- Hyperplastic Polyps:
3- Pseudopolyps :
4- Hamartomatous Polyps: these include
* Juvenile polyps :
* Peutz-Jeghers Syndrome:
Adenomas:
- Tubular adenoma (adenomatous polyp).
- Villous adenoma (papillary adenoma).
- Tubulo-villous adenoma
what is Peutz-Jeghers Syndrome
mucocutaneous hyperpigmentation and increased risk
of several malignancies as cancer colon, breaşrt, lung,
ovaries and others.
mucocutaneous hyperpigmentation and increased risk
of several malignancies as cancer colon, breaşrt, lung,
ovaries and others.
Peutz-Jeghers Syndrome
tumors of small and large intestine
benign epithelial tumors: adenomas
benign mesenchymal: leiomyoma, schwannoma, lipoma, fibroma, angioma
malignant epithelial: carinoid and adenocarcinoma
malignant mesenchymal: lymphoma
malignant mesenchymal tumors of small and large intestine
- Lymphoma
- Leiomyosarcoma
benign epithelial tumors of colon
adenomas
the hereditary tumors of the colon
Familial Adenomatous Polyposis
hereditary non-polyposis colerectal cancer
diagnosis of FAP (familial adenomatous polyposis)
A count of at least 100 polyps is necessary for diagnosis of classic FAP
malignant epithelial tumors of colon
carcinoid and adenocarcinoma
gene mutation cause FAP
adenomatous polyposis coli gene (APC gene), a
tumor suppressor gene.
complication of FAP
Colorectal carcinoma
gene mutation cause Hereditary non polyposis colorectal cancer
DNA mismatch repair gene
treatment of FAP
Prophylactic colectomy
complication of HNPCC syndrome
colorectal cancer
exocolonic cancer
common location of the HNPCC
right proximal colon
other name of HNPCC syndrome
Lynch syndrome
common location of adenocarcinoma of colon
rectosigmoid
most common gastrointestinal malignancy
adenocarcinoma
predisposing factors of adenocarcinoma of colon
1- Adenomas: All adenomas.
2- Diet: high fat & low fiber
3- Ulcerative colitis with dysplasia
4- Familial adenomatous polyposis
Gross of adenocarcinoma of colon in proximal and distal
- Polypoid fungating mass (more in proximal colon).
- Malignant ulcer.
- Annular stricture (more in distal colon).
microsopic picture adenocarcinoma of colon
- Adenocarcinoma formed of infiltrating malignant glands
- Mucoid carcinoma (minority).
- Poorly differentiated carcinoma without gland formation (rare and poor prognosis).
- Signet ring carcinoma (rare and poor prognosis)
- Invasive tumors
complication of adenocarcinoma
1- Intestinal obstruction: Mechanical obstruction of lumen by tumor.
2- Intussuception (tumor induces abnormal peristalsis).
3- Hemorrhage from ulceration or tumor necrosis.
4- Perforation leads to septic peritonitis .
5- Spread:
-transcoelomic spread : kurkenberg syndrome
-direct: malignant fistula formation.
- Lymphatic
- Blood spread mainly to the liver.
carcinoid tumor of Colon arise from?
neuroendocrine (argentaffine’) cells
Modified Dukes’ staging related to
adenocarcinoma of colon
what is Modified Dukes’ staging:
staging according to invasion of muscularis propria, and presence or absence of lymph node metastases
staging of Modified Dukes’
Stage A: tumor which is confined to submucosa or muscle layer
Stage B: tumor has spread through the muscle layer but without lymph node metastases
B1 extendining into muscularis propria
B2 penetrating through muscularis propria
Stage C: Any tumor involving lymph nodes.
C1 extendining into muscularis propria, with lymph node metastases.
C2 penetrating through muscularis propria, with lymph node metastases.
commonest site of carcinoid tumor
appendix
gross of carcinoid tumor of colon
Yellow firm nodule
microscopic of carcinoid tumor of the colon
- groups of monotonous cuboidal cell.
- The cytoplasm is rich in argyrophilc granules, observed by EM or by silver stains
tumor cells that cytoplasm is rich in argyrophilc granules
carcinoid tumor
manifestations of carcinoid syndrome
1- Fibrous stenosis of tricuspid and pulmonary valve.
2- Bronchoconstriction producing bronchospasm.
3- Skin flushing, oedma and diarrhea.
CARC
cutaneous flushing, asthmatic bronchoconstriction, right sided stenosis, cramps (diarrhea)
behavior of carcinoid tumor
typical
atypical (high incidence of distant metastasis as liver metastasis which release serotonin and other substances leading to carcinoid syndrome
liver metastasis of carcinoid release
serotonin
commnest malignant tumor in small intestine
lymphoma
definition of bleeding per rectum
Passage of fresh red blood in stools
causes of bleeding per rectum
A- Local causes: Intestinal (anywhere below the stomach & duodenum).
1- Polyps
2- Malignant tumors
3- Piles (hemorrhoids)
4- Bilharziasis
5- Typhoid ulcers
6- Tuberculous ulcers
7- Amebic dysentery
8- Bacillary dysentery
9- Ankylostomiasis.
B-General causes of bleeding:
Ø Hemophilia, purpura, leukemia, and vit. C and vit. K deficiency
MATBP //// HBL 2 def
Passage of dark altered blood in the stools
melena
causes of hematemesis
A- Local causes: Bleeding from lesions high in the GIT above duodenum (mostly gastric & esophageal). The causes are similar to causes of hematemesis.
B- General causes of bleeding.
definition of melena
Passage of dark altered blood in the stools
Definition of hemorides
varicosity’s of hemorrhoidal veins in lower rectum
Types of hemorrides
- Internal: in superior hemorrhoidal veins.
- External: in Inferior hemorrhoidal veins
Etiology of hemorrides
1- Portal hypertension.
2- Congenital weakness of vessel walls.
3- Obstruction of lumen by tumor in rectum.
4- Chronic right sided heart failure with systemic venous congestion
Complications of hemorrides
1- Hemorrhage fatal or microcytic hypochromic iron deficiency anemia
2- Thrombosis, septic thrombophlebitis & pyemia.
3- Strangulation of piles & their prolapse.
