Stomach - Pathoma

Question 1

What is Gastroschisis?

Answer 1

• Congenital malformation of abdominal wall
  
  • hole in abdominal wall
• Leads to exposure of abdominal contents

Question 2

What is an Omphalocele?

Answer 2

• Persistent herniation of bowel into umbilical cord
  
  • contents are covered by peritoneum and amnion of umbilical cord

Question 3

What is an Omphalocele due to?

Answer 3

• Failure of herniated intestines to return to body cavity during development

Question 4

What is pyloric stenosis?

Answer 4

Congenital hypertrophy of pyloric smooth muscle

(tightening of pyloric sphincter)

Question 5

Is pyloric stenosis more common in males or females?

Answer 5

MALES

Question 6

How does pyloric stenosis present clinically?

Answer 6

• 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

Question 7

What is the treatment for pyloric stenosis?

Answer 7

Myotomy

Question 8

What is acute gastritis?

Answer 8

• Acidic damage to mucosa
  
  • “burning” of stomach by acid

Question 9

What is acute gastritis due to?

Answer 9

Imbalance between mucosal defenses and acidic environment

• Caused by either:
  
  • increased acid secretion
  • decreased protection by mucosa

Question 10

What are the two types of Chronic Gastritis?

Answer 10

1. Chronic Autoimmune Gastritis
2. Chronic H. pylori Gastritis

Question 11

What are the defenses normally present in the Mucosa of the stomach?

Answer 11

• Epithelial lining (folveolar cells)
• Mucus layer
• Bicarbonate secretion
• Normal blood supply providing nutrients and absorbing acid

Question 12

What are the risk factors for Gastritis?

Answer 12

• 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

Question 13

Acid damage results in what three pathologic findings?

Answer 13

• Superficial inflammation
• Erosion
  
  • loss of epithelium
• Ulcer
  
  • loss of mucosal layer

Question 14

What happens in Chronic Autoimmune Gastritis? What is the damage associated with?

Answer 14

• 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

Question 15

What clinical features are seen in Chronic Autoimmune Gastritis?

Answer 15

• 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

Question 16

What is the most common cause of Vitamin B12 deficiency?

Answer 16

Chronic Gastritis

Question 17

Because chronic inflammation induces intestinal metaplasia, patients with Chronic Gastritis are at increased risk for what?

Answer 17

Gastric Adenocarcinoma

Question 18

What is the most common form of gastritis?

Answer 18

Chronic H. pylori Gastritis

90%

(H.pylori-induced acute and chronic inflammation)

Question 19

What properties of H. pylori allows it to weaken mucosal defenses?

Answer 19

• Proteases
• Ureases
• Inflammation

Question 20

What is the most common site of H.pylori infection in the stomach?

Answer 20

Antrum

Question 21

Patients with H.pylori-induced gastritis are at increased risk for what conditions?

Answer 21

• Ulceration
• Gastric adenocarcinoma
• MALT lymphoma
  
  • generate germinal centers within gastric wall => develop post-germinal center B-cells => form marginal zone => Mucosa-Associated Lymphoid Tissue!

Question 22

What is the best way to resolve H.pylori gastritis/ulcers and reverse intestinal metaplasia?

Answer 22

Triple therapy treatment

Question 23

What diagnostic findings confirm eradication of H.pylori?

Answer 23

• Negative urea breath test
• Lack of stool antigen

Question 24

What is peptic ulcer disease?

Answer 24

Solitary mucosal ulcer involving proximal duodenum (90%) or distal stomach (10%).

Question 25

Duodenal ulcers are almost always due to what?

Answer 25

H.pylori (rarely due to Zollinger-Ellison syndrome)

Question 26

How do patients with Peptic Ulcer Disease present clinically?

Answer 26

* Epigastric pain that improves with meals * meal promotes =\> duodenum increases defenses and makes neutralizing substances

Question 27

What will diagnostic endoscopic biopsy show in Peptic Ulcer Disease?

Answer 27

Ulcer with hypertrophy of Brunner glands

Question 28

What is the major complication of a duodenal ulcer?

Answer 28

* Rupture * can lead to: * bleeding from the gastroduodenal artery (posterior ulcers) * acute pancreatitis (posterior ulcers)

Question 29

What causes gastric ulcers in Peptic Ulcer Disease?

Answer 29

* Usually H.pylori * NSAIDs * Bile reflux

Question 30

What clinical presentation distinguishes Gastric Ulcers from Duodenal Ulcers?

Answer 30

Gastric ulcers =\> pain WORSENS with meals

Question 31

Where are Gastric Ulcers usually located in the stomach?

Answer 31

* Lesser curvature of the antrum * rupture carries risk of bleeding from left gastric artery

Question 32

What important disease should be included in the DDx of Ulcers?

Answer 32

CANCER * Duodenal ulcers are almost never malignant * Gastric ulcers can be caused by gastric carcinoma

Question 33

What is Gastric Carcinoma?

Answer 33

Malignant proliferation of gastric epithelial cells (epithelial cells = columnar cells =\> adenocarcinoma)

Question 34

What defines the Intestinal Type Gastric Carcinomas?

Answer 34

* Presents as large, irregular ulcer with heaped up margins

Question 35

Where are the Intestinal Type ulcers in gastic carcinoma usually found?

Answer 35

Most commonly involves lesser curvature of antrum

Question 36

What are the risk factors for Intestinal Type ulcers in gastic carcinoma?

Answer 36

* Intestinal metaplasia * chronic gastritis * Nitrosamines in smoked food * Blood type A

Question 37

What defines the Diffuse Type gastric carcinoma?

Answer 37

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

Question 38

Unlike Intestinal Type, the Diffuse Type gastric carcinoma are not associated with what three things?

Answer 38

* H. pylori * intestinal metaplasia * nitrosamines

Question 39

What is the clinical presentation of Gastric Carcinoma?

Answer 39

* PRESENTS LATE! * Weight loss * Abdominal pain * Anemia * Early satiety * Rarely presents with acanthosis nigricans or Leser-Trelat sign

Question 40

Where does Gastric Carcinoma spread to?

Answer 40

Left supraclavicular node (Virchow node - drains the stomach)

Question 41

Distant metastasis of gastric cancer most commonly involves what organ?

Answer 41

The LIVER * Periumbilical type * Sister Mary Joseph nodule * seen with intestinal type * Bilateral ovaries * Krukenburg tumor * seen with diffuse type