Pathology of the Small Bowel Flashcards
What are the 2 main causes of ischaemia of the small bowel
Mesenteric arterial occlusion
Non occlusive perfusion insufficiency
Is bowel ischamia acute or chronic
Usually acute but can be chronic
What can cause mesenteric arterial occlusion
Mesenteric artery atherosclerosis
THromboembolism from heart
What can cause non occlusive perfusion insufficiency
Shock
Strangulation obstructing venous return
Drugs (cocaine)
Hyperviscosity
What is the most metabolically active part of the bowel wall
The mucosa- most sensitive to the effects of hypoxia
What happens to the cyrpts in muscosal infarction
They die
What are 3 complications of ischaemia of the small bowel
Resolution
Fibrosis, stricture, chronic ischaemia
mesenteric angina and bstruction
Gangrene, perforation, peritonitis, sepsis and death
What is Meckel’s Diverticulum
A congenital abnormality which is a result of incomplete regression of vitello-intestinal duct
What might Meckel’s diverticulum mimic
Appendicitis
Are primary or secondary tumours more common
Secondary (metastases)
Tumours of the small bowel are metastases from which 3 places
Ovary
Colon
Stomach
What are 3 types of primary tumours of the small bowel
Lymphomas
Carcinoid tumours
Carcinomas (Adenocarcinomas)
What are all lymphomas of the small bowel
Non Hodkins in type
How can we treat lymphomas of the small bowel
Treated by surgery and chemotherapy
Where is the commonest site of carcinoid tumours of the small bowel
Appendix
Describe the typical appearance of carcinoid tumours of the small bowel
Small, yellow, slow growing tumours
Describe the typical appearance of carcinoid tumours of the small bowel
Small, yellow, slow growing tumours
What are carcinomas of the small bowel commonly associated with
Crohn’s disease and Coeliac disease
Where do carcinomas of the small bowel metastasise to?
Lymph nodes and liver
What are 4 common presentations of appendicitis
Vomiting
Abdo pain
RIF tenderness
Increased WCC
What causes acute appendicitis
Unknown Faecoliths (dehydration) Lymphoid hyperplasia Parasites Tumours (rare)
What must acute inflammation involve in appendicitis
Muscle coat
What are 5 complications of appendicitis
Peritonitis Rupture Abscess Fistula Sepsis and liver abscess
What is coeliac diseased
Caused by an abnormal reaction to a constituent of what flour, gluten, which damages enterocytes and reduces absorptive capacity
It is a lifelong condition
What 2 things is coeliac disease associated with
dematitis herpetiformis
childhood diabetes
When can coeliac disease present
Childhood, middle age or adulthood
When can coeliac disease present
Childhood, middle age or adulthood
What is the suspected toxic agent
Gliadin (a protein component of gluten)
What are the 2 clinical features of coeliac disease
Mucosa may be endoscopically normal or appear attenuated
Lesion worse in proximal bowel so duodenal biopsy is very sensitive (not an ileal biopsy)
What is tested in serology
Antibodies: anti-TTG, anti-endomesial, anti-gliadin
What are 2 metabolic effects of coeliac disease
Malabsorbtion of sugars, fats, amino acids, water and electroyltes
Malabsorption of fats leads to steatorrhowa
What can reduce pancreatic secretion and bile flow leading to gallstones
Reduced intestinal hormone production
What are 5 presentations of coeliac disease
Loss of weight Anaemia (Fe, Vit B12, Folate) Abdominal bloating Failure to thrive Vitamin deficiencies
What are 4 complications of coleiac disease
T cell lymphomas of GI tract
Increased risk of small bowel carcinoma
Gall stones
Ulcerative- jejenoilleitis
