T1 PC Pathology of the Gut Flashcards
What happens in Baretts Oesophagus?
the distal (end) oesophagus lined by gastric mucosa undergoes intestinal metaplasia to develop into goblet cells and columnar cells
From what part of the oesophagus does intestinal metaplasia start in Baretts Oesophagus?
the abnormal cells start from where the oesophagus meets the stomach and spread upwards
What type of epithelium lines the oesophagus?
Non keratinising stratified squamous epithelium
What causes metaplasia?
the reflux of gastric contents leading to reflux oesophagitis
Where is the oesophago-gastric junction located?
between the oesophagus and the stomach
What are the risk factors for BO?
High BMI, alcohol, smoking
Drugs which relax the lower oesophageal sphincter
having a familial / genetic predisposition
What’s an example of a drug that relaxes the lower oesophageal sphincter?
Nitroglycerins
What is the process by which Baretts Oesophagus occurs?
reflux oesophagitis is caused by the reflux of acidic contents from the stomach into the oesophagus
triggers the metaplasia of squamous epithelium into columnar epithelium, which is an adaption to injury caused by the gastric contents
What does the presence of columnar epithelium in BO increase the risk of?
of adenocarcinoma of the oesophagus via dysplasia
What are the features of a BO with cancer?
a polyp protrudes into the open lumen
the oesophagus is lined by white squamous epithelium
ther stomach is the same colour (pink) as BO
What are the stages of 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 is the difference between TX and T0 in cancer staging?
TX: Main tumor cannot be measured.
T0: Main tumor cannot be found.
What does T1 - T4 refer to in cancer staging?
the size and/or extent of the main tumor
the higher the number after the T, the larger the tumor or the more it has grown into nearby tissues
T’s may be further divided to provide more detail, such as T3a and T3b
What are the four microscopic features of coeliac disease in small bowel mucosa?
Villous atrophy
Crypt hyperplasia
Increase in intra-epithelial lymphocytes
Chronic inflammation
What are examples of complications of coeliac disease?
Refractory to treatment
Cancers of the small bowel, large bowl and pancreas
Osteoporosis, infertility
What conditions are associated with coeliac disease?
Dermatitis herpetiformis
Primary biliary cirrhosis
Autoimmune hepatitis, Autoimmune thyroiditis
Type 1 Diabetes mellitus
What is the predominant cell of chronic inflammation?
Lymphocytes
What is the predominant cell of acute inflammation?
Neutrophil or polymorph
What are the features of normal large bowel mucosa?
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
What are the features of UC in small bowel mucosa?
inflammation is confined to the mucosa
crypt architecture distortion
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 proportion of the intestine can be covered in creeping fat?
as much as half o fth eintestine
What is the histology of Crohn’s Disease?
Transmural inflammation = involves full thickness of bowel wall
fissuring ulcer
No crypt architecture distortion
What are the symptoms of strictures in the SI or LI?
Abdominal pain due to intestinal obstruction
What are examples of complications of Crohn’s disease??
strictures Intra-abdominal abscess Sinus tract formation Fistulas e.g. colo-vesical; patient will present with pneumaturia Cancer
What are the effects of a colovesical fistula?
painful infections and other complications
What causes a colovesical fistula?
an open connection between the LI and the bladder
What is change in bowel habit?
Constipation alternating with diarrhoea
What is normal varies for each patient
What does Stage 0 mean in cancer?
that abnormal cells are present but have not spread to nearby tissue - is not cancer, but it may become cancer
What is Stage 0 otherwise known as?
carcinoma in situ
What does Stage 1-3 mean in cancer?
that cancer is present. The higher the number, the larger the cancer tumor and the more it has spread into nearby tissues
What does Stage IV mean in cancer?
that the cancer has spread to distant parts of the body.
What are outpouchings caused by?
Diverticular Disease - the herniation of the mucosa and submucosa through the bowel wall at sites of weakness
In what populations are outpouchings common in?
in the populations on low fibre diet
What percentage of diverticular disease cases affect the sigmoid colon?
95%
What are the complications of diverticular disease?
peritonitis caused by diverticulitis & perforation
How might diverticular disease present?
with intestinal obstruction
can mimic cancer
colo-vesical fistula
pneumaturia
