PAT 2 Flashcards
Microscopic picture of Autoimmune associated gastritis
- Chronic inflammation:
- The inflammatory infiltrate is predominantly lymphocytes, macrophages, & plasma cells; lymphoid aggregates can be present. - There is marked glandular atrophy & fibrosis of the lamina propria.
- In long standing cases, intestinal metaplasia occurs.
- This is a premalignant condition and carcinoma develops in a small proportion of patients
Clinical picture of autoimmune associated Gastritis
Hypoacidity & anemia.
- B12 deficiency can also manifest with
( Atrophic glossitis - Peripheral neuropathy & Spinal cord lesions. )
complication of B12 deficiency
( Atrophic glossitis - Peripheral neuropathy & Spinal cord lesions. )
the most common cause of chronic gastritis
H. pylori infection
Pathogenesis of Helicobacter pylori (HP) associated chronic gastritis
- The organism is found in the mucus layer of gastric epithelium.
- The acute inflammatory response is mediated by complement activation and attraction of neutrophils
- The neutrophils release proteases and reactive oxygen species which may be responsible for glandular destruction
what is type B gastritis
Helicobacter pylori (HP) associated chronic gastritis
what is responsible for glandular destruction in HP gastritis
The neutrophils release proteases and reactive oxygen species which may be responsible for glandular destruction
Morphology of HP gastritis
1) antral gastritis with high acid production; high rik of duodenal ulcer
2) diffuse involvement of antrum and body (pangastritis) with
multifocal glandular atrophy and fibrosis, and decreased acid output: gastric ulcer and carcinoma
Microscopic of HP gastritis
- A variable number of neutrophils are present intraepithelial and collect in the lumen of gastric pits.
- Lamina propria contains abundant plasma cells, macrophages, & lymphocytes, and in case of severe infiltrate the rugal folds are seen grossly thickened.
- Long-standing gastritis is associated with diffuse mucosal atrophy, with prominent lymphoid aggregates occasionally with germinal centers
- The organisms are generally seen in the mucus layer on the cell surface as slender, curved rods.
Diagnosis of H. pylori
© Antibody serologic test,
© Urea breath test,
© Bacterial culture,
© Direct bacterial visualization in gastric biopsy, or
© DNA-based tests.
Fate & complications of HP gastritis
- Severe cases usually proceed to atrophy with intestinal metaplasia which is precancerous, and can lead to adenocarcinoma.
- H. pylori infection is also a risk factor for peptic ulcer disease, & gastric lymphoma.
Microscopic Picture of Acute Gastric Ulceration
- Ulcers include layers of necrosis, inflammation, & granulation tissue.
- Fibrotic scar is absent
Fate and complications of acute gastric ulceration
- Severe bleeding can occur.
- Healing with complete re-epithelialization occurs, after the injurious factors are removed
Lesions associated with
brain injury are due to direct vagal stimulation causing gastric acid hypersecretion
cushing ulcers
types of acute gastric ulceration
stress ulcer, curling ulcer, cushing ulcer
Gross Picture of acute gastric ulceration
- Ulcers are usually smaller than 1 cm in diameter, multiple, and shallow
- Found anywhere in the stomach.
- The ulcer base is brown (blood), while the adjacent mucosa is normal.
Definition of the peptic ulcer
§ Chronic mucosal defects, also affecting submucosa,
as a result of acid and pepsin attack.
§ They occur mostly in stomach & duodenum
(but also anywhere exposed to the action of acid & pepsin secretion)
Sites of the peptic ulcer
1- First part of the duodenum.
2- Stomach: lesser curvature & pyloric antrum..
3- Lower esophagus associated with reflux of acid from stomach.
4- Meckel’s diverticulum:
a congenital remnant of the vitello-intestinal duct containing heterotropic
gastric mucosa (foci of gastric mucosa amidst the intestinal mucosal lining).
5- Distal duodenum & jejunum in Zollinger Ellison syndrome.
6- Gastro-jejenostomy stomal ulcer (surgical opening of stomach into the jejunum) due to dumping of acid & pepsin.
Pathogenesis of peptic ulcer
- Hyperacidity or
- Failure of mucosal defence mechanism,
what is meckel’s diverticulum
a congenital remnant of the vitello-intestinal duct containing heterotropic gastric mucosa (foci of gastric mucosa amidst the intestinal mucosal lining)
why peptic ulcer in distal duodenum & jejunum
due to Zollinger Ellison syndrome
stomal ulcer related to
Gastro-jejenostomy surgery
causes of hyperacidity
- Helicobacter pylori causes excess HCL secretion.
- Gastrinoma (gastrin producing tumor) in Zollinger Ellison syndrome:
- Chronic stress with high vagal tone
cause of damage of mucus barrier of stomach
Duodeno-gastric reflux
epithelial barrier is damaged by
- Chronic NSAID use (direct damage, blocking prostaglandin production)
- High doses of corticosteroids (suppress prostaglandin synthesis).
- Chronic alcoholism.
- H pylori infection (cytotoxins or inflammatory reaction).
- Smoking especially in presence of H pylori infection
الكاس و المزاج و الكورتيزون و البيلوري
The mucosal defence mechanism of the stomach consist of
- A mucus-bicarbonate barrier
- The surface epithelium
Fate of peptic ulcer
Ulcers heal by epithelial regeneration and underlying fibrosis.
Microscopically: the peptic ulcer
The base of the ulcer shows necrotic tissue
with polymorphs overlying granulation tissue merging with fibrosis.
Gross of the peptic ulcer
© usually solitary (80% of patients), 1-2 cm,
© round or oval in shape with sharp sloping or terraced edges.
© The floor is smooth due to peptic digestion of any exudate.
© The base is firm due to fibrosis.
clinical picture of peptic ulcer
- Chronic recurrent disease in middle aged or older adults.
- Epigastric pain 1-3 hours after meals, releaved by alkali or food (duodenal ulcer)
- gastric ulcer after food immediatly .
complication of peptic ulcer
- Bleeding, from eroded vessels at base of ulcer, manifests as:
* Hematemesis.
* Melena (in acute bleeding).
* Iron deficiency anemia (chronic bleeding). - Penetration into solid viscera as pancreas (organs of stomach bed).
- Pyloric obstruction in ulcers of pyloric antrum. The fibrosis causes narrowing &
obstruction of gastric outlet - Perforation into peritoneal cavity causing peritonitis.
- Malignant transformation only in gastric ulcer can rarely occur
ulcer causes iron def anemia
peptic ulcer (complication)
benign epithelial tumors of stomach
Polyps
benign mesechymal tumors of the stomach
- Leiomyoma
- Schwannoma
- Benign gastrointestinal stromal tumor (GIST)
malignant mesenchymal stomach
- Lymphoma
- Leiomyosarcoma .
- Neurogenic sarcoma
- Malignant gastro intestinal stromal tumor (GIST)
malignant epithelial stomach
Gastric carcinoma
predisposing factors of carcinoma of stomach
- In H pylori gastritis, there is a sequence of events of atrophy, intestinal metaplasia, dysplasia and carcinoma.
- Smoked food
- Autoimmune gastritis type A
- Genetic factors
- Adenomatous polyp
why H pylori causes carcinoma of stomach
- Hypochlorohydria associated with atrophy favors the growth of bacteria that catalyse the formation of carcinogenic nitrosamines.
- High cell turnover
- The epithelial damage induce increased cell proliferation, with probable acquired mutations which are transmitted to daughter cells
- Loss of E cadherins (in diffuse gastric cancer) and mutations of tumor suppressor genes have been demonstrated in gastric cancer.
morphology of Gastric carcinoma
Lauren classification separates gastric carcinoma to intestinal adenocarcinoma
lauren classifiction related to
morphology of gastric carcinoma
lauren classification of gastric carcinoma
p 68
difference of early gastric carcinoma and advanced
Early gastric cancer is confined to the mucosa or submucosa and
The advanced cancer have extended in or beyond the muscle layer
exophytic
masses or an ulcerated mass appear in carcinoma
Intestinal type adenocarcinoma
morphology of intestinal type adenocarcinoma
- Tend to be bulky, appear as exophytic masses or an ulcerated mass.
- Composed of glands with variable degree of differentiation, and secrete mucin.
- If in excess the term mucoid adenocarcinoma is used.
- Intestinal type predominates in high risk areas and develop from dysplasia and adenoma.
morphology of Diffuse gastric cancer
- Shows an infiltrative growth pattern.
- Composed of dyscohesive cells which infiltrate the mucosa as single cells.
- They evoke a desmoplastic reaction that stiffen the gastric wall and cause diffuse flattening of gastric rugae giving the stomach a leather bottle appearance (linitis plastica).
- The cells may have large intracytoplasmic mucin vacuoles that push the nucleus to one side (signet ring carcinoma).
- No definite precursor lesion.
clinical picture of gastric carcinoma
Ø early symptoms resemble those for chronic gastritis (i.e., dysphagia, dyspepsia, & nausea).
Ø Advanced stages present with weight loss, anorexia, altered bowel habits, anemia, & hemorrhage.
Complications of gastric carcinoma
1- Hematemesis & melena.
2- Pyloric obstruction resulting in severe vomiting & dehydration.
3- Anemia due to recurrent bleeding with microcytic hypochromic anemia.
4- Spread
- Direct spread: to duodenum, pancreas and retroperitoneum. - Lymphatic spread:
to perigastric - celiac- paraortic lymph nodes .and then to left supraclavicular lymph nodes** (Virchows node)**.
- Blood spread : through portal vein to liver.
- Transcoelomic:
producing peritoneal deposits &
deposits in both ovaries causing
enlargement of the ovaries (Krukenberg tumor of the ovaries)
the most common mesenchymal tumor of the abdomen
GASTROINTESTINAL STROMAL TUMOR GIST
origin of GIST
interstitial cell of Cajal
location of interstitial cell of Cajal
located in the muscularis propria and serve as pacemaker for the gut
cancer develops from the lymphoid follicles in H pylori gastritis
acquired mucosa-associated lymphoid tissue or MALT
high grade lymphoma of stomach
diffuse large B cell lymphoma
fate of acquired mucosa-associated lymphoid tissue or MALT
show complete regression after
complete eradication of H pylori infection
etiology of GIST
tyrosine kinase (C-KIT) mutation
treatment of GIST
imatinib (an inhibitor of the tyrosine kinase activity)
what is kurkenberg tumor
metastatic deposits from gastric carcinoma to both ovaries casing enlargment of them
Definition of INTESTINAL ATRESIA
Failure of the gut to canalize,
most commonly found in the duodenum or small intestine
Definition of Meckel’s Diverticulum
remnant of the vitello-intestinal duct
which makes tubular blind pouch present on the antimesenteric border of small intestine
length of the M diverticulum
2 inch (5cm)
length from the iliocoecal junction
2-3 feet (60-90 cm)
complication of meckel’s diverticulum
- It may contain heterotropic gastric epithelium, which may secrete acid & pepsin resulting in peptic ulcer.
- Acute intestinal obstruction: Meckel’s diverticulum can result in
abnormal twisting of a loop of intestine on itself (volvulus)
causing acute intestinal obstruction. - May get inflamed and present as acute abdomen mimicking acute ‘appendicitis.
location of the meckel’s diverticulum
the antimesenteric border of small intestine
Etiology of Hirschsprung’s Disease (Megacolon)
Ø Congenital absence of the ganglionic cells in the myenteric plexus of the intestine at the recto-sigmoid junction.
Ø Peristalsis stops at the affected site resulting in functional obstruction leading to chronic intestinal obstruction
which congentital disorder causes acute intestinal obstruction
Meckel’s Diverticulum
which congentital disorder causes chronic intestinal obstruction
Hirschsprung’s Disease (Megacolon)
Clinical picture of Hirschsprung’s Disease (Megacolon)
Pain, vomiting, constipation, and distension
PVCD
treatment of the megacolon
incision of the distal collupsed part
Hirschsprung’s Disease (Megacolon) causes which type of intestinal obstruction
chronic
Gross of Hirschsprung’s Disease (Megacolon)
he aganglionic segment is narrow markedly dilated colon proximal to it (Megacolon).
The intestinal wall is thickened due to hypertrophy of the muscle wall
Definition of Acute intestinal obstruction
Sudden complete bowel obstruction
Types of Acute intestinal obstruction
function (paralytic ileus) and Organic
Causes of the paralytic ileus
- A segment of the intestine loses its peristaltic movement.
- Caused by operative trauma to the intestine or septic peritonitis disturb the normal autonomic control of peristalsis.
causes of organic obstruction
a) Strangulated hernia
b) Adhesions of healed peritoneal inflammation
c) Lumen obstruction: by foreign body, worms or fecolith (solid stools) or tumor.
d) Volvulus:
e) Intussusception:
f) Thrombosis or embolism of mesenteric artery
Definition of stangulated hernia
A hernia is a loop of intestine which passes through a congenital or acquired defect in the abdominal wall results in obstructing the mesentry vessels
Definition of Volvulus
Volvulus is complete twisting of a bowel loop about its mesenteric
vascular base, leading to vascular and luminal obstruction with infarction
causes of lumen acute obstruction
foreign body, worms or fecolith (solid stools) or tumor
common part that volvulus occur
sigmoid colon
Intussusception is common in
infants and children
in older age intussusception is caused by
benign tumor, parasitic irritation, bilharzial polyps or abnormal motility
results of thrombosis of the mesenteric artery
Producing hemorrhagic infarction
of a segment which loses its peristalsis & doesn’t function
Gross of acute intestinal obstruction
- The proximal segment is markedly dilated, edematous wall.
- The mucosa is congested with loss of its folds (stretched), with
accumulation of fluid & gas in the lumen. - The distal segment is collapsed
Complications of acute Intestinal obstruction
1- Septic peritonitis; bacteria pass through the devitalized wall from the lumen into the sterile peritoneum.
2- Gangrene: the marked dilatation causes compression on the vessels of the wall leading to ischemic necrosis, which quickly undergoes putrefaction, wet gangrene perforation, septic peritonitis.
3- Septicemia 2ry to peritonitis
Clinical Picture of acute intestinal obstruction
- Abdominal distention, persistent vomiting leading to dehydration & shock (hypovolemic). Loss of K affects the cardiac rhythm.
- No passage of stools or flatus (gas).
- Plain X ray shows distention of intestine with gas and presence of a fluid level.
Definiton of chronic intestinal obstruction
Gradual incomplete obstruction
Etiology of Chronic intestinal obstruction
1- Lumen obstruction.
2- Fibrous stricture following dysentries, ulcerative colitis, Crohn’s disease or TB.
3- Endophytic tumor benign or malignant growing into the lumen
4- Obstruction from outside: Pressure of a tumor & adhesions between intestinal loops.
5- Annular stricture carcinoma.
6- Hirschsprung’s disease
Defintion of Malabsorption
Malabsorption is a disease characterized by defective absorption of fats, proteins, carbohydrates, water, electrolytes, minerals, fat and water soluble vitamins
Gross of chronic intestinal obstruction
§ Proximal segment: Above obstruction there is dilatation, hypertrophy of wall (muscle contracts more forcibly to enable pushing of contents beyond the obstruction).
The lumen contains accumulating liquified food & gases (action of bacteria).
§ Distal segment: Below obstruction: the segment is collapsed (no contents)
Etiology of malabsorption
1- Celiac Disease (gluten-induced enteropathy)
2- Tropical sprue
3- Giardiasis
4- Secondary malabsorption:
pathogenesis of Celia disease
- Hypersensitivity reaction to a protein in wheat.
- Characterized by total villous atrophy of small intestine
Characterized by partial villous atrophy of the small intestine
Tropical sprue causing malabsorption
Characterized by total villous atrophy of small intestine
Celiac Disease (gluten-induced enteropathy)
Clinical Picture of mal absorption
Chronic diarrhea, weight loss, abdominal distension and muscle wasting.
A hallmark of malabsorption is steatorrhea characterized by excessive fecal fat and bulky, frothy, greasy, yellow or clay colored stools.
what is secondary malabsorption
omplicating other diseases with diffuse distruction
of small intestinal mucosa, eg:
- Intestinal lymphomas.
- TB ulcers (2ry),
- Crohn’s disease (regional ileitis).
- Surgical intestinal anastomosis (reduce the intestinal length.
- leading to decrease surface absorption).
- Extensive surgical resections (short gut)
Bronchial asthma G & M
Gross:
Lungs are overinflated
Bronchial wall is thick, swollen & red.
Bronchial lumen contains large amounts of thick mucus plugs
Microscopic:
Bronchial lumen
§ Occlusion of bronchi and bronchioles by mucus
plugs which contain whorls of shed epithelium
known as Curschmann spirals.
§ Numerous eosinophils and Charcot-Leyden
crystals derived from eosinophils are also
present.
Bronchial wall
§ mucous gland hypertrophy.
§ smooth muscle hypertrophy,
§ thickening of basement membrane
Curschmann spirals related to
bronchial asthma
Charcot-Leyden crystals related to
bronchial asthma
