Pathology of the gut Flashcards
What is Barretts oesophagus?
Distal oesophagus is lined by columnar cells due to metaplasia; the oesophagus is lined by gastric mucosa, which can develop goblet cells in another process termed intestinal metaplasia.
What type of epithelium lines the oesophagus?
- What is metaplasia?
- What causes the metaplasia?
What type of epithelium lines the oesophagus?
Non keratinising stratified squamous epithelium
- What is metaplasia?
Is the differentiation of one mature epithelium to another mature epithelium
- What causes the metaplasia?
Reflux of gastric contents leading to reflux oesophagitis
What does this show?
The OGJ or Z Line
What is the type of epithelium in the oesophageal muscosa?
Oesophageal Mucosa – non keratinising stratified squamous epithelium
What are the risk factors for Barretts Oesophagus
- High BMI
- Alcohol drinking
- Tobacco smoking
- Drugs which relaxes the lower oesophageal sphincter e.g. Nitroglycerins,
- Familial/genetic predisposition
What is th Pathogenesis of BO?
- Reflux of acidic contents from the stomach into the oesophagus leads to reflux oesophagitis
- Squamous epithelium changes to columnar epithelium in a process of metaplasia
- The metaplastic process is an adaption to injury caused by the gastric contents
- Columnar epithelium increases the risk of adenocarcinoma of the oesophagus through a precancerous stage called dysplasia
What does this show?
BO at endoscopy
What does this show?
- BO with Cancer – the ‘polyp’ (P) protruding into the open lumen
- A = oesophagus lined by white squamous epithelium
- Longitudinal black line is BO i.e. columnar cell lined oesophagus
- Arrow = OGJ
- B= Stomach with the same colour ( pink) as BO
What is the Pathogenesis of Barrett’s Associated Carcinoma?
Squamous epithelium
↓
Reflux oesophagitis
↓
Gastric epithelium
↓
Intestinal metaplasia
↓
Low grade dysplasia
↓
High grade dysplasia
↓
Adenocarcinoma
•How does a patient with oesophageal cancer present?
•Dysphagia initially for solids then for liquids
What does this show?
T-CELL LYMHOMA SMALL BOWEL
What does this show?
CANCER OF THE LARGE BOWEL
- The histology showed small bowel T-cell lymphoma as a complication of coeliac disease
- And stage T2 N0 cancer of the ascending colon
- Which cancer has worse prognosis?
T-cell lymphoma
What is the diagnosis?
Coeliac disease
A. Name Four microscopic features of coeliac disease
B. Other complications of coeliac disease
C. Other conditions associated with coeliac disease
A. Four microscopic features of coeliac disease
- Villous atrophy
- Crypt hyperplasia
- Increase in intra-epithelial lymphocytes
- Chronic inflammation
B. Other complications of coeliac disease
- Refractory to treatment
- Cancers of small bowel, large bowl and pancreas
- Osteoporosis, infertility
C. Other conditions associated with coeliac disease
Dermatitis herpetiformis; Primary biliary cirrhosis,
Autoimmune hepatitis, Type 1 Diabetes mellitus;
Autoimmune thyroiditis
- 47-year-old man decided he wanted to lead a healthy lifestyle
- Started to eat well, going to the gym three times a week and presented to his GP with diarrhoea a few months later
- What questions would you ask him?
- Does he smoke? This patient stopped smoking which triggered latent ulcerative colitis
- Diarrhoea how many times/day?
- Is there blood/mucus in the stool?
- Is stool smelly?
- What is the predominant cell of chronic inflammation?
- What is the predominant cell of acute inflammation?
•What is the predominant cell of chronic inflammation?
Lymphocyte
•What is the predominant cell of acute inflammation?
Neutrophil or polymorph
What does this show?
Case 2: Gross pathology UC-diffusely haemorrhagic and ulcerated mucosa
What are the microscopic features of normal large bowel muscosa?
- The crypts are arranged in a row reminiscent of test tubes
- The goblet cells are full of mucin
- The crypts are separated by the lamina propria with vessels and connective tissue
Is this normal small or large bowel mucosa?
Large bowel
What does this show?
Ulcerative Colitis: inflammation confined to the mucosa + crypt architecture distortion
Case 2: What are the indications for colectomy in UC?
- Refractory to treatment
- Toxic megacolon
- Severe bleeding
- High grade dysplasia
- Cancer
What are the Risk Factors for Dysplasia in UC?
- UC at an early age
- Total UC - involving the whole large bowel
- Repeated bouts of acute inflammation with short periods of remission
- Long duration with UC; patients with total UC for 8years require annual surveillance colonoscopy to look for dysplasia
What is the feature illustrated in this specimen?
CD
Fat wrapping
