L19: Colorectal Cancer Flashcards
What is the small intestine divided into
Duodenum
Jejenum
Ileum
What is the junction between the small and large bowel
Ileocaecal junction
What is the large bowel divided into
Cecum Ascending colon Transverse colon Descending colon Sigmoid colon
What are the layers of the small bowel
Innermost layer: mucosa (made of the epithelium, lamina propia and musclaris mucosa
Second layer: submucosa and muscularis (inner and outer longitudinal muscle)
Third outer layer: serosa made of the areolar connective tissue and epithelium
What is the difference in small and large bowel mucosa
Small bowel:
Place circulares and vili for absorption
Crypts that have paneth cells
Large bowel:
Does not have villi
Has crypts but no paneth cells
What are the 2 condition in a inflammatory bowel disease
Crohn’s disease
Ulcerative colitis
What areas does Crohn’s disease affect
The entire GIT
What layers does Crohn’s disease affect
All the layers (transmural)
What areas does ulcerative colitis occur at
Colon and rectum and is continues
What areas does ulcerative colitis affect in the bowel
Mucosa
Which IBD is worsened by smoking
Crohn’s disease
What can form in inflammatory bowel disease as a complication
Stricture
What type of stricture will form in ulcerative colitis
Mucosal
What type of stricture will form in Crohn’s disease
Transmurla stricture
What can transmural strictures cause
Bowel obstruction
What are the complication in Crohn’s disease
Stricture Fistula: tube between the 2 epithelial lining Abscess Malabsorption Gallstones Steatorrhea B12 and vitamin d Fatigue
What are the complication in ulcerative colitis
Strictures Toxic megacolon Bowel obstruction Malignancy Fatigue Venous thrombosis Cholangiocarcinoma Arthritis
What are the symptoms of IBD
Abdominal pain Diarrhoea Pr bleeding Pyrexia Weight loss Malnutrition Dry red eyes Back pain Stiff joints
What investigations can be carried in IBD
Bloods: fbc, CRP, LFT, UE, blood cultures if pyrexic
Imaging: Cxr, AXR, ct scan
Endoscopy: colonoscopy, gastroscopy
What criteria can we use to assess the severity ulcerative colitis
True love and witts criteria
What is the distribution of inflammation like in Crohn’s
Patchy
What is the distribution of inflammation like in ulcerative colitis
Continous
Which layers are affected in Crohn’s disease
Transmural (all layers)
Which layers are affected in ulcerative colitis
Mucosal
Which IBD can show granuloma on macroscopy
Crohn’s disease
Which IBD can show fibrosis
Crohn’s disease
Which IBD is likely to present with fistulas
Crohn’s disease
What is the management of IBD
Reduce inflammation; steroids and antibiotics
Fluid replacement
Accurate stool record
VTE prophalyxis- due to high risk of them developing clots due to hypercoaguable state due to inflammation
What is the long term management of IBD
Surgery
Immunotherapy e.g aminosalicyclic acid
What are IBD patients at risk of developing
Colorectal cancer
What is the commonest type of colorectal cancer
Adenocarcinoma
What are the 3 types of adenomas
Tubular
Villous
Tubuvillous
What are colonic adenomas
Benign precursors to colorectal cancer characterised by dysplastic epithelium
What is the presentation of a colonic adenoma
Usually asymptomatic
Large polyp that can cause bleed and cause anaemia
Villous adenoma can lead to hypokalaemia
What is the adenoma carcinoma sequence
A sequence of how a adenoma can transform into a carcinoma
Describe the adenoma carcinoma sequence
- Starts off with normal colon
- Normal colon transforms into a adenomatour polyp with genetic endogenous factors
- Endogenous and exogenous factors can then from the adenoma into a dysplastic polyp
- Increase in oxidative stress can cause dysplastic polyp into a colon cancer
What are examples of endogenous factors that can cause adenomatous polyp to dysplastic polyp
Inflammation
Oxidative stress
What are exogenous factors that can cause adenomatous polyp to dysplastic polyp
Drugs
Smoking
Diet
Obesity
Which part of the colon does a colorectal cancer most commonly affect
The rectum
What can a right sided cancer present as
Anaemia Changes in bowel habit Right iliac fossa mass Bowel obstruction Acute appendicitis
What can a left sided cancer present as
Pr bleeding
Change in bowel habit
Left iliac fossa mass
Bowel obstruction
What can rectal tumours present as
Pr bleed
A sense of incomplete pooing as the tumour enlarges it will stretch the rectum and result in a sensation
Morning diarrhoea
Perforation, haemmorhage or fistula
What is the most common tumour marker for colorectal cancer to look for in the blood
CEA
What other blood test can be carried out in colorectal cancer
FBC: anaemia
LFT: degrranged lfts for liver mets
Renal profile- if a pelvic tumout obstruct the ureters it can cause post renal aki
What imaging can be carried out in colorectal cancer
AXR
Cxr
Ct abdomen and pelvis
What invasive procedures can be carried to investiagate for colorectal cancer
Endoscopy
Flexible sigmoidoscopy
Colonoscopy- for right sided tumours
Which Criteria do we use to stage colorectal cancer
Duke staging
What does the staging represent
the extent of spread of the cancer
Where can colorectal cancer spread
Locally to the intestinal wall to the ovaries and the bladder
Distant sites: liver, lung and peritoneum
