Pathology of Colorectal Cancer

Question 1

What is a polyp?

Answer 1

Protrusion above the epithelial surface

It is a tumour (a swelling)

Question 2

What are the two types of polyp?

Answer 2

Epithelial

Mesenchymal

Question 3

What are the most common types of polyps?

Answer 3

epithelial - adenocarcinomas

Question 4

What are the 3 formations a polyp can have?

Answer 4

Peduncuated – easy to remove
Sessile – harder to remove
flat – harder to remove

Question 5

What is the adenoma-carcinoma sequence?

Answer 5

Normal mucosa ->
Adenoma (dysplastic) ->
Adenocarcinoma (invasive)

Question 6

What creates a small adenoma?

Answer 6

aggressive mutation of genetic mutation

Question 7

Why must all adenocarcinomas be removed and how is this done?

Answer 7

Because they are all premalignant

Either done endoscopically or surgically

Question 8

What is the primary treatment for adenocarcinoma?

Answer 8

surgery

Question 9

What are the stages of Dukes staging of colerectal carcinoma staging?

Answer 9

Dukes A: Confined by muscularis propria

Dukes B: Through muscularis propria

Dukes C: Metastatic to lymph nodes

Question 10

Where does left sided colerectal cancer occur?

Answer 10

rectum, sigmoid, descending

-left sided is more common than right

Question 11

What is the presenting complaint of left sided colerectal cancer?

Answer 11

Blood PR, Altered bowel habit, Obstruction

Question 12

Where does right sided colerectal cancer occur?

Answer 12

Caecum, Ascending

Question 13

What is the presenting complaint of right sided colerectal cancer?

Answer 13

Anaemia, Weight loss

Question 14

What are the two types of inheretid colorectal cancer?

Answer 14

Heriditary Non Polyposis Coli (HNPCC)

Familial Adenomatous Polyposis (FAP)

Question 15

Describe Heriditary Non Polyposis Coli (HNPCC)?

Answer 15

< 100 polyps

• presents with cancer later in life
• Autosomal dominant
• Defect in DNA mismatch repair
• Inherited mutation in MLH-1, MSH-2, PMS-1 or MSH-6 genes
• Right sided tumours
• Mucinous tumours
• Crohn’s like Inflammatory response
• Associated with gastric and endometrial carcinoma

Question 16

Describe Familial Adenomatous Polyposis (FAP)?

Answer 16

>100 polyps
Early onset
Autosomal dominant
Defect in tumour supression
Inherited mutation in FAP gene
Colerectomy is necessary
Throughout colon
Adenocarcinoma NOS
No specific inflammatory response
Associated with desmoid tumours and thyroid carcinoma