Peptic Ulcer Disease and Premalignant Conditions
Peptic Ulcer Disease and Helicobacter pylori
- Peptic ulcer disease is often caused by Helicobacter pylori (H. pylori).
- H. pylori is an extracellular bacterium, unlike Tropherma whipplei in Whipple's disease, which is intracellular.
- H. pylori causes type B gastritis, the leading cause of peptic ulcer disease.
Microbiology of H. pylori
- Gram-negative coccobacillus: It can switch between coccoid and bacillus forms.
- Non-sporing: Eradication with antibiotics is possible since it won't come back as spores.
- Spread: Via the fecal-oral route, explaining the higher incidence in developing countries.
- Microaerophilic: Requires less oxygen and can survive in the stomach environment.
Mechanism of Action
- Urease Production: H. pylori produces urease, which generates ammonia.
- Ammonia's Effect: Ammonia is alkaline and irritates G cells.
- G Cell Stimulation: Leads to excessive gastrin production.
- Hyperchlorhydria: Excessive gastrin stimulates parietal cells, leading to increased acid production (hyperchlorhydria).
- Impact on Duodenum: Excess acid flows into the duodenum, causing duodenal ulcers because the duodenum lacks the stomach's protective prostaglandins.
Duodenal Ulcer Symptoms
- Epigastric Pain: Occurs when the stomach empties, typically two hours after eating.
- Snacking: Patients often snack to alleviate pain, leading to weight gain due to increased calorie and fat intake.
- Hypergastrinemia and Hyperchlorhydria: Both conditions are present.
Achlorhydria and Ulcers
- Even with less acid (achlorhydria), ulcers can occur due to weakened stomach defense mechanisms.
Diagnosis of H. pylori
- Initial Test: Breath urea test is preferred as a non-invasive screening test.
- Eradication Test: Breath urea test is also used to determine the eradication of H. pylori infection.
- Urease Test (CLO test): An invasive test involving a stomach scraping during endoscopy.
- Biopsy: Warthensari stain (silver stain) is of historical importance and is not typically used for diagnosis nowdays.
Treatment
- Antibiotics:
- Clarithromycin and amoxicillin combination is commonly prescribed for two weeks.
- Ampicillin can be used but has a higher incidence of diarrhea.
- Tetracycline and metronidazole (or ornidazole) can also be used in combination.
- Erythromycin has not been shown to be effective against H. pylori.
- PPI: Proton pump inhibitors are given for 4-6 weeks to heal ulcers.
- Triple Therapy: Two antibiotics with a PPI.
- Quadruple Therapy: Two antibiotics, PPI, and a surface protective agent like bismuth.
- Bismuth reduces acid mucosa contact time.
Type A Gastritis
Characteristics
- Hypergastrinemia: Similar to type B gastritis but with achlorhydria (less acid production).
- Etiology: Autoimmune, with antibodies against parietal cells.
- B12 Deficiency: Parietal cells produce intrinsic factor, so their destruction leads to B12 deficiency, causing pernicious anemia or megaloblastic anemia.
- Pre-Malignant Condition: Gastric ulcers develop due to weakened stomach defense mechanisms.
Gastric vs. Duodenal Ulcers
Associations
- Gastric Ulcer: Related to blood group A.
- Duodenal Ulcer: Related to blood group O (remember "DUO").
Location
- Gastric Ulcer: Commonly on the lesser curvature near incisura angularis (Type 1 gastric ulcer based on Johnson classification).
- Duodenal Ulcer: Commonly in the first part of the duodenum, known as the duodenal cap.
Presentation
- Gastric Ulcer:
- Pain starts soon after eating.
- Patients avoid food, leading to weight loss.
- Often consume milk, curd, or soup.
- Duodenal Ulcer:
- Pain occurs every two hours (stomach emptying time).
- Patients snack frequently, leading to weight gain.
Investigation
- Upper GI Endoscopy: Used to visualize the ulcer and perform a biopsy (especially for gastric ulcers to rule out malignancy).
- Urease Test: Often performed in Indian settings due to the higher incidence of H. pylori.
Treatment
- PPIs: Given for 4-6 weeks for ulcer healing.
- Antibiotics: Prescribed based on urease test results.
Refractory Peptic Ulcer Disease
- Consider Zollinger-Ellison Syndrome: Suspect this if the ulcer heals with PPIs but recurs upon stopping them.
- Secretory Diarrhea: A key symptom in Zollinger-Ellison syndrome.
Complications of Gastric vs. Duodenal Ulcers
Bleeding
- Gastric Ulcer: Bleeding from the left gastric artery.
- Duodenal Ulcer: Posterior duodenal ulcer bleeds from the gastroduodenal artery.
- Management: Fluid resuscitation, upper GI endoscopy, and cauterization of the ulcer base.
Perforation
- Gastric Ulcer:
- Fluid leaks into the lesser sac via the foramen of Winslow, causing lesser sac peritonitis.
- Duodenal Ulcer:
- More common than gastric ulcer perforation.
- Fluid accumulates in the greater sac, causing greater sac peritonitis.
- Anterior duodenal ulcers are more prone to perforation.
- Overall most common cause of peritonitis is a perforated duodenal ulver.
Penetration
- Gastric Ulcer:
- Slow acid erosion into the posterior wall, potentially damaging the pancreas and causing necrotizing pancreatitis.
Obstruction
- Gastric Ulcer:
- Pyloric stenosis due to pylorus spasm and reactive fibrotic changes, leading to "teapot stomach."
Image-Based Questions
Gas Under Diaphragm
- Signifies a perforation with peritonitis. Also known as the "Moustache sign."
Reverse Moustache Sign
- Seen in acute pulmonary edema due to prominent pulmonary veins.
- Air around the heart, known as "continuous diaphragm sign."
- Associated with Boerhaave syndrome (esophageal rupture).
Subcutaneous Emphysema
- Air in the chest wall, often seen with chest trauma or Boerhaave syndrome.
Coffee Bean Sign
- Seen in sigmoid volvulus.
Birdbeak Appearance
- On barium enema, indicates sigmoid volvulus.
Key X-Ray Findings (Must Not Miss):
- Pneumothorax
- Pneumoperitoneum (gas under diaphragm)
- Pneumomediastinum
Sigmoid Volvulus Case
Presentation
- 60-year-old male with left iliac fossa pain and obstipation (inability to pass flatus).
Diagnosis
- X-ray shows a large bubble obstruction (coffee bean sign).
Rotation
- Sigmoid volvulus rotates anticlockwise; cecal volvulus rotates clockwise.
Management
- Pass a flatus tube.
- Fluid resuscitation.
- Colonoscopic detorsion; unlike stomach volvulus, exploratory laparotomy is generally not needed.
Diverticulitis Case
Presentation
- 60-year-old hardcore non-vegetarian with chronic constipation, severe left iliac fossa pain, and hematochezia (fresh blood in stool).
Diagnosis
- Diverticulitis, a leading cause of lower GI bleeding.
Investigation
- CT abdomen is the preferred test.
- Barium enema is used for diverticulosis, not diverticulitis.
Premalignant Conditions in the GI Tract (Top to Bottom)
Oral Cavity
- Oral Submucosal Fibrosis: Due to gutka or betel nut use.
- Leukoplakia: White patches; more common.
- Erythroplakia: Red patches.
- Syphilitic Glossitis.
- Oral Lichen Planus: Controversial; low chance of malignancy but considered premalignant.
Esophagus
- Tylosis Palmaris: Hyperkeratosis of palms and soles linked to squamous cell carcinoma.
- Achalasia (HL Asiocardia): Increased lower esophageal sphincter tone.
- Barrett's Esophagus: Due to GERD.
- Plummer-Vinson Syndrome (Patterson-Kelly Syndrome):
- Esophageal web (post-cricoid dysphagia).
- Iron deficiency anemia.
- Koilonychia (spoon-shaped nails).
- Note: Glossitis is mentioned in some pathology resources but not consistently in gastroenterology.
- Koilocytes: HPV-infected cervical cells from the cervix.
- Leukonychia: White nails in liver disease.
Stomach
- Gastric Ulcer.
- Type A Gastritis.
- Ménétrier's Disease:
- Foveolar cell proliferation, leading to achlorhydria.
- Cerebriform appearance of stomach mucosa (enlarged rugosities).
- Treatment: Monoclonal antibody cetuximab (not gastrectomy).
Small Intestine
- Crohn's Disease (also in large intestine).
- Cronkhite-Canada Syndrome: Sporadic hamartomatous polyps.
- Piotr Sager Syndrome: Hamartomatous polyps with mucosal melanosis.
Large Intestine
- Familial Adenomatous Polyposis (FAP): APC gene on chromosome 5.
- More than 100 polyps in the colon.
- Prophylactic colectomy is performed to prevent adenocarcinoma.
- Inflammatory Bowel Disease.
- Genetics: Autosomal dominant, chromosome 19, STK11 and LKB1 genes.
- Arborizing Pattern: Polyps with a plant-like growth pattern.
- Mucosal Melanosis: Spots around the lips and inner orifice (palmar creases and knuckles are NOT involved as they would be in cases of Addison's disease).
- Manifestations: Hamartomatous polyps, mainly in the jejunum.
- Cancer Development: Increased risk of stomach cancer, ovarian cancer, cervical cancer, and hepatobiliary cancer. The polyps in the jejunum may not turn malignant.
- Pre-Malignancy: Plus/minus; the incidence of cancer in extra-intestinal sites is increased.
- Compared to oral lichen planus and Piotr-Jeghers Syndrome: Both have a lower chance of turning premalignant.