Pathology of Upper GI Tract Flashcards
What is a classic presentation of mouth cancer?
An ulcer which will not heal and persists without a definite, identifiable cause
Name some risk factors for upper GI cancer?
Smoking
Alcohol
HPV
What are the components of the GI wall?
Mucosa (non-keratinising stratified squamous epithelium) Musculatise mucosae Submucosa Muscularis propria Advenitia
What happens to the histology of the gut wall when it comes into contact with acid?
Injure the squamous epithelium lining of the oesophagus
Increased number of inflammatory cells
Basal, proliferation zone of the epithelium is hyperplasic
What infections can you get in the oesophagus?
Candida albicans (fungus) Herpes simplex virus
Name some causes of chemical inflammation of the oesophagus.
Peptic oesophagitis/GORD: relfux of acid or bile Lye (NaOH, caustic soda) Iron Bisposphonates Tetracyclines
Describe the pathology of a candida oesphagitis infection.
Active chronic inflammation with many neutrophils especially near the luminal surface
Describe the pathology of a herpes simplex infection.
Atypical sqaumous cells
- empty looking
Inflammatory exudate and cells (slough)
What is eosinophilic oesophagitis?
Overlap with reflex oesphagitits
Causes dysplasis
More common in younger people
May have a dietary sensitiser
What is the pathology of an eosinophilic oesophagitis?
Eosinophils infiltrate oesphageal squamous epithelium Allergic aetiology - responsive to steriods (Fluticasone) Trachealisation - ring-like
Which kind of oesophageal cancer is associated with smoking and drinking?
Squamous cell carcinoma
Which kind of oesophageal cancer is associated with GORD and obesity?
Oesphageal adenocarcinoma
What is Barrett’s oesophagus?
Metaplastic response to mucosal injury
- squamous becomes glandular
- with goblet cells
What is Barrett’s oesophagus associated with?
Benign strcitures
Adenocarcinomas
- dysplasia to carcinoma progression over years
- definite low grade and high grade dysplasia increases risk of developing cancer
What is the Seattle biopsy protocol?
4 biopsies every 2cm
- effective at finding dysplasia
May be replaced by targeted biopsy as endoscopy improves
How is oesophageal cancer treated?
Radiofrequency ablation
Endoscopic treatments
Describe the dysplasia spectrum.
Inflammation with reactive changes Indefinite for dysplasia Mild, moderate (low grade) dysplasia Severe (high grade) dysplasia Invasive adenocarcinoma (intramucosal, submucosal)
How do you recognise dysplasia?
Architecturally and cytologically abnormal Low grade - cells polarised - nuclei stratified High grade - polarity lost - rounder nuclei - vesicular, prominent nucleoli - abnormal mitosis - necrosis
Name some of the acute and chronic causes of gastritis?
Acute - alcohol, NASIDs, severe trauma (burns and surgery) Chronic - Autoimmune - Bacterial (H.Pylori) - Chemical
Describe the normal absorption of B12.
B12 bound to salivary Haptocorrin is protected from gastric acid
Haptocorrin is digested by the duodenum
B12 binds to intrinsic factor secreted by gastric parietal cells
- absorbed in the terminal ileum via specialised receptors
Describe autoimmune gastritis.
Autoimmune destruction of parietal cells
- anti-parietal cell antibodies in the blood
Eventual complete loss of parietal cells with pyloric and intestinal metaplasia
Acholrhydria allows bacterial overgrowth
Persistant inflammation leads to epithelial dysplasia and possibly cancer
What is Zollinger-Ellison Syndrome?
Hypersecretion of gastrin by an endocrine tumour (gastrinoma) in the pancreas or duodenum
- increased gastric acid output
- severe peptic ulceration
Describe H.Pylori gastritis.
Potentialy lifelone H.Pylori colonises gastric mucosa
- active chronic inflammation
- IL-8 is released from epithelial cells to attract neutrophils
When in the antrum, specifically causes antral-predominant gastritis
- hypergastrinaemia and duodenal ulceration
Pangastritis
- hyperchlorhydria
- multi-focal atrophic gastritis
- intestinal type cancer
What is the characteristic morphology of chemical gastritis?
Few inflammatory cells Surface congestion oedema Elongation of gastric pits Tortuosity Reactive hyperplasia/atypia Ulceration Affects the antrum more than the corpus
What is the background histology of gastric cancer?
Atrophic mucosa
Chronic inflammation
Intestinal metaplasia
Dysplasia
Describe diffuse gastric cancer.
Individual malignant cells with mucin vacuoles
- signet ring cells
May invade extensively without being endoscopically obvious (linitis plastica)
Weak link with gastritis
Commonly metastasises to the ovaries
What is familial gastric cancer and how is it managed?
CDH1 (E-Cadherin) mutation
- 70-80% penetrance
Small intramucosal foci of diffuse gastric cancer
Associated risk of lobular carcinoma of the breast
Treated with prophylactic gastrectomy
Why are rates of distal gastric cancer decreasing while rates of proximal gastric cancer are increasing?
Distal
- rates of H.Pylori are gradually being reduced
Proximal
- obesity and poor diet is increasing, as are rates of GORD
