Pathology: Stomach & Duodenum Flashcards
What are potential causes of acute gastritis?
- irritant chemical injury
- severe burns
- severe trauma
- shock
- head injury
What are potential causes of chronic gastritis?
- autoimmune
- bacterial e.g. H.Pylori
- chemical
What cell types are rarely associated with gastritis?
- eosinophilic
- lymphocytic
- granulomatous
What is rarest cause of gastritis?
autoimmune
What is most common cause of gastritis?
H.pylori infection
How does autoimmune gastritis affect the stomach?
- atrophic gastritis
- intestinal metaplasia (dysplasia of stomach cells)
- loss of parietal cells, achlorhydria and intrinsic factor deficiency
What is achlorhydria?
Loss of hydrochloric acid in gastric secretions
What clinical syndrome is often associated with autoimmune gastritis?
Pernicious anaemia
What causes loss of parietal cells and intrinsic factor deficiency in autoimmune gastritis?
Anti-parietal and anti-intrinsic factor antibodies
What risk is increased with autoimmune gastritis?
Malignancy (due to metaplasia)
What is SACDC and what is it often associated with?
- Sub acute combined degeneration of the spinal cord
- often associated with pernicious aneamia
What causes pernicious anaemia?
Autoimmune disorder due to atrophic gastritis with loss of parietal cells with consequent failure of intrinsic factor production meaning malabsorption of vitamin B12 (Gastric intrinsic factor is associated with B12 absorption)
What type of anaemia is pernicious anaemia?
macrocytic
Describe H.pylori as a bacteria?
- Gram negative
- curvilinear rod
Where does H.pylori bacteria inhabit?
-niche between epithelial cell surface and mucous barrier
What is the inflammation process of H.pylori infections?
Excites early acute inflammatory response and if not cleared then chronic inflammatory response follows
What cytokine is important in H.pylori response?
IL8
What cells produce H.pylori antibodies and where are these cells located?
- Plasma cells
- Lamina propria
What do H.pylori infections lead to an increased risk in?
Increased risk in:
- gastric ulcer
- duodenal ulcer
- gastric carcinoma
- gastric lymphoma
How do H.pylori infections look histopathologically?
Lots of little/big circles like blobs of infection throughout edge of stomach.
What can cause chemical gastritis?
- NSAIDs
- alcohol
- bile reflux
What can cause direct injury to mucous layer?
fat solvents
What are histopathological signs of chemical gastritis?
- epithelial regeneration
- hyperplasia
- congestion
- little inflammation
What can chemical gastritis cause?
- erosions
- ulcers
How can chemical gastritis present endoscopically?
Black dots along lining
What is the difference between peptic ulcer and erosions?
Both are superficial breaks in the mucosa however peptic ulcers can penetrate down to muscularis mucosa.
What is a peptic ulcer?
Breach in the gastriointestinal mucosa due to acid and pepsin attack
Where do chronic peptic ulcers usually present?
- duodenum (1st part)
- stomach (junction of body and antrum)
- gastro-oesophageal junction
- stomal ulcers
What size do peptic ulcers range from?
2-10cm
How do peptic ulcers appear through endoscope?
edges are clear cut and looks punched out
What are the two factors of pathogenesis of peptic ulcers?
- increased acid + pepsin production (due to hypersecretory state)
- defect in mucosal defence mechanisms (e.g. due to gastric hyperacidity, NSAIDs, alcohol)
Outline the concept of synergism in relation to peptic ulcers.
Synergism is where sum of effects is greater than individual effects by themselves. In this case its combination of increased acidity combined with defect in mucosal defence mechanisms (increased attack and failure of defence)
What does excess acid in duodenum cause?
Gastric metaplasia and consequent H.pylori infection, inflammation, epithelial damage and ulceration
What do many duodenal peptic ulcer patients have?
Inappropriately sustained acid secretion
How do peptic ulcers present microscopically and what is each layer?
- layered appearance:
- floor of fibrinopurulent debris
- base of inflamed granulation tissue
- deepest layer is fibrotic scar tissue
What is fibrinopurulent debris?
Pus or suppurative exudate containing relatively large amount of fibrin
What is granulation tissue and what does it contain?
- Tissue that grows during repair of soft tissue wounds
- connective tissue cells and young blood vessels
What are 5 complications of peptic ulcers?
- perforation
- penetration
- haemorrhage
- stenosis
- intractable pain
What are two benign gastric polyps?
- hyperplastic polyps
- cystic fundic gland polyps
What are three types of malignant gastric tumours?
- carcinoma (adenocarcinomas)
- lymphoma
- gastrointestinal stromal tumours (GISTs)
What is the stroma?
The connective tissue cells that form the framework of an organ as opposed to parenchyma (functioning part)
What type of gastric adenocarcinomas are increasing in incidence in UK and which are decreasing?
- Proximal tumours of cardia/GOJ increasing
- distal tumours decreasing
What is often prevalent in patients with gastric adenocarcinomas?
H.pylori infections
What is the pathogenesis of gastric adenocarcinomas?
H.pylori infection -> chronic gastritis -> intestinal metaplasia/atrophy -> dysplasia -> carcinoma
What is intestinal metaplasia?
The transformation of mucosa (particularly stomach) into glandular mucosa that resembles intestinal mucosa, increase in goblet cells
What are 5 potential causes of gastric adenocarcinoma?
- H.pylori infections
- pernicious anaemia
- partial gastrectomy
- HNPCC/Lynch Syndrome
- Menetrier Disease
What is HNPCC and what is another name for it?
- Hereditary nonpolyposis colorectal cancer
- AKA Lynch Syndrome
What is Menetrier disease?
Characterised by massive overgrowth of mucosal cells in stomach resulting in large gastric folds
What are the two types of gastric adenocarcinoma and explain the types?
- intestinal type i.e. polypoid mass, exophytic
- diffuse type i.e. expands and infiltrates stomach wall
How can you tell the difference between malignant gastric adenocarcinoma and peptic ulcer?
Peptic ulcer don’t have raised rolled edge and is more punched out
What is linitis plastica?
Type of stomach adenocarcinoma that causes stomach tissue to be thicker and “leather-like”
What type of cancer is signet ring cell adenocarcinoma in stomach?
-Diffuse type
How does signet ring cell adenocarcinoma look histopathologically?
Like little rings or white blobs of cells
What are 3 types of diffuse gastric adenocarcinoma?
- signet ring cell
- linitis plastica
- sclerosis
Which of intestinal or diffuse carcinoma has better prognosis?
Intestinal
Where do gastric adenocarcinomas spread?
- locally e.g. organs, peritoneal cavity, ovaries
- lymph nodes
- haematogenous (to liver)
What is a kruckenberg tumour?
Malignancy in the ovary that metastasised from a primary site usually gastric adenocarcinoma
What structures form in intestinal gastric adenocarcinoma?
glandular structures
What is another name for gastric lymphoma?
Maltoma - mucosa associated lymphoid tumour
What stomach infection is gastric lymphoma/maltoma associated with?
H.pylori infection
What is the pathogenesis of gastric lymphoma?
Chronic inflammation -> evolution into a clonal B-cell proliferation (low-grade)
What happens if low-grade gastric lymphoma is untreated?
Evolves into high-grade B cell lymphoma
