Stomach - Pathoma Flashcards
What is Gastroschisis?
- Congenital malformation of abdominal wall
- hole in abdominal wall
- Leads to exposure of abdominal contents
What is an Omphalocele?
- Persistent herniation of bowel into umbilical cord
- contents are covered by peritoneum and amnion of umbilical cord
What is an Omphalocele due to?
- Failure of herniated intestines to return to body cavity during development
What is pyloric stenosis?
Congenital hypertrophy of pyloric smooth muscle
(tightening of pyloric sphincter)
Is pyloric stenosis more common in males or females?
MALES
How does pyloric stenosis present clinically?
- Not present at birth! => Takes time for stenosis to develop
- present 2 weeks after birth with projectile nonbilious vomiting
- peristalsis can be visible on abdomen
- “olive-like” mass in abdomen
What is the treatment for pyloric stenosis?
Myotomy
What is acute gastritis?
- Acidic damage to mucosa
- “burning” of stomach by acid
What is acute gastritis due to?
Imbalance between mucosal defenses and acidic environment
- Caused by either:
- increased acid secretion
- decreased protection by mucosa
What are the two types of Chronic Gastritis?
- Chronic Autoimmune Gastritis
- Chronic H. pylori Gastritis
What are the defenses normally present in the Mucosa of the stomach?
- Epithelial lining (folveolar cells)
- Mucus layer
- Bicarbonate secretion
- Normal blood supply providing nutrients and absorbing acid
What are the risk factors for Gastritis?
- Severe burn (Curling ulcer)
- hypovolemia, decreased blood flow, nutrient deficiency to mucosa
- NSAIDs
- prostaglandins decrease acid production, increase blood flow, activate mucus producing cells
- Heavy alcohol consumption
- Chemotherapy
- knock out cells that are turning over => can’t regenerate cells in the stomach
- Increased intracranial pressure (Cushing ulcer)
- increased vagal stimulation => increased ACh => binds parietal cell receptor => increased acid production
- Shock
- severely decreased blood flow to stomach
Acid damage results in what three pathologic findings?
- Superficial inflammation
- Erosion
- loss of epithelium
- Ulcer
- loss of mucosal layer
What happens in Chronic Autoimmune Gastritis? What is the damage associated with?
- Autoimmune destruction of gastric parietal cells
- in the body and fundus
- T-cell mediated damage (Type IV HSR)
- Associated with antibodies against parietal cells and/or intrinsic factor in the blood
- useful for diagnosis
What clinical features are seen in Chronic Autoimmune Gastritis?
- Atrophy of mucosa
- Achlorhydria (low acid production) with increased Gastrin levels (loss of negative feedback) and antral G-cell hyperplasia
- knocked out parietal cells
- Megaloblastic (pernicious) anemia
- due to lack of intrinsic factor
What is the most common cause of Vitamin B12 deficiency?
Chronic Gastritis
Because chronic inflammation induces intestinal metaplasia, patients with Chronic Gastritis are at increased risk for what?
Gastric Adenocarcinoma
What is the most common form of gastritis?
Chronic H. pylori Gastritis
90%
(H.pylori-induced acute and chronic inflammation)
What properties of H. pylori allows it to weaken mucosal defenses?
- Proteases
- Ureases
- Inflammation
What is the most common site of H.pylori infection in the stomach?
Antrum
Patients with H.pylori-induced gastritis are at increased risk for what conditions?
- Ulceration
- Gastric adenocarcinoma
- MALT lymphoma
- generate germinal centers within gastric wall => develop post-germinal center B-cells => form marginal zone => Mucosa-Associated Lymphoid Tissue!
What is the best way to resolve H.pylori gastritis/ulcers and reverse intestinal metaplasia?
Triple therapy treatment
What diagnostic findings confirm eradication of H.pylori?
- Negative urea breath test
- Lack of stool antigen
What is peptic ulcer disease?
Solitary mucosal ulcer involving proximal duodenum (90%) or distal stomach (10%).
Duodenal ulcers are almost always due to what?
H.pylori
(rarely due to Zollinger-Ellison syndrome)
How do patients with Peptic Ulcer Disease present clinically?
- Epigastric pain that improves with meals
- meal promotes => duodenum increases defenses and makes neutralizing substances
What will diagnostic endoscopic biopsy show in Peptic Ulcer Disease?
Ulcer with hypertrophy of Brunner glands
What is the major complication of a duodenal ulcer?
- Rupture
- can lead to:
- bleeding from the gastroduodenal artery (posterior ulcers)
- acute pancreatitis (posterior ulcers)
- can lead to:
What causes gastric ulcers in Peptic Ulcer Disease?
- Usually H.pylori
- NSAIDs
- Bile reflux
What clinical presentation distinguishes Gastric Ulcers from Duodenal Ulcers?
Gastric ulcers => pain WORSENS with meals
Where are Gastric Ulcers usually located in the stomach?
- Lesser curvature of the antrum
- rupture carries risk of bleeding from left gastric artery
What important disease should be included in the DDx of Ulcers?
CANCER
- Duodenal ulcers are almost never malignant
- Gastric ulcers can be caused by gastric carcinoma
What is Gastric Carcinoma?
Malignant proliferation of gastric epithelial cells
(epithelial cells = columnar cells => adenocarcinoma)
What defines the Intestinal Type Gastric Carcinomas?
- Presents as large, irregular ulcer with heaped up margins
Where are the Intestinal Type ulcers in gastic carcinoma usually found?
Most commonly involves lesser curvature of antrum
What are the risk factors for Intestinal Type ulcers in gastic carcinoma?
- Intestinal metaplasia
- chronic gastritis
- Nitrosamines in smoked food
- Blood type A
What defines the Diffuse Type gastric carcinoma?
Signet ring cells that diffusely infiltrate gastric wall
- Signet ring cell = intracellular mucus pushing nucleus peripheral
- Desmoplasia results in a thickening of stomach wall (linitis plastica)
- Desmoplasia = fibrous tissue and blood vessels in response to tumor
Unlike Intestinal Type, the Diffuse Type gastric carcinoma are not associated with what three things?
- H. pylori
- intestinal metaplasia
- nitrosamines
What is the clinical presentation of Gastric Carcinoma?
- PRESENTS LATE!
- Weight loss
- Abdominal pain
- Anemia
- Early satiety
- Rarely presents with acanthosis nigricans or Leser-Trelat sign
Where does Gastric Carcinoma spread to?
Left supraclavicular node (Virchow node - drains the stomach)
Distant metastasis of gastric cancer most commonly involves what organ?
The LIVER
- Periumbilical type
- Sister Mary Joseph nodule
- seen with intestinal type
- Bilateral ovaries
- Krukenburg tumor
- seen with diffuse type
