Colorectal

Question 1

4 layers of intestines

Answer 1

Serosa (int)
Adrentitia (ref)
Muscularis
Submucosa
Mucosa

Question 2

Mucosa has

Answer 2

Glands/crypts

Question 3

Most carcinomas are -

Answer 3

Come from the layer lining glands

Are Adenomas

Question 4

Occur due to

Answer 4

Sporadic mutation

Butt sometimes due to known mutations APC

Question 5

If apc mutates then

Answer 5

Allows uncontrolled division which leads to polyps

Polyps can accumulate mutations in other genes and become malignant tumour

Question 6

Risky polyps

Answer 6

Premalignant/neoplasticism polyps

Question 7

Types of neoplasticism polyps

Answer 7

Adenomatous- normal appearance
APC mutation

Serrated-

Mutations in DNA repair genes

Saw tooth appearance

Question 8

Stages

Answer 8

0- not past mucosa 
1 beyond mucosa
2 entire wall, may reach nearby organs 
3 lymph
4 metastatic

Question 9

Risk factors

Answer 9

Being elderly 
Inflammatory bowel disease
Cig smoke 
Red meat 
Obesity
Familial adenomatous polyposis

Question 10

Symptoms

Answer 10

Ascending: pain +weight loss no bowel obstruction , grows large = late diagnosis

Can ulcerate + bleed = anaemia

Descending:

Ring shaped masses
Cause lumen narrowing
Pain
Blood in stool

Question 11

Diagnosis

Answer 11

Colonoscopy
Fecal occult blood
Testing for GI bleeding

Barium enema
Inject fluid and look for abnormality apple core sign ( constriction of lumen most likely In descending colon)