Colorectal Carcinoma

Question 1

What is the inheritance of Familial Adenomatous Polyposis

Answer 1

Autosomal Dominant

Question 2

What is the inheritance pattern of Peutz-Jeghers Syndrome?

Answer 2

Autosomal Dominant

Question 3

What is FAP caused by and how does it present

Answer 3

Caused by a mutation in the APC gene

Patients develop thousands of polyps and are at extremely high risk of developing cancer (90% develop cancer by age 50)

Question 4

How does Peutz-Jeghers present

Answer 4

Multiple polyps in the small intestine and colon PLUS melanin pigmentation of the lips, mouth and digits

Question 5

what is the first line investigation for colorectal cancer

Answer 5

Colonoscopy –> lesions can be biopsied and polyps removed

Question 6

Give some risk factors for colorectal cancer

Answer 6

• Long standing/extensive UC/Chron’s
• Acromegaly
• Pelvic radiotherapy
• Red meat and animal fats
• Cholecystectomy
• obesity/T2DM/sedentary lifestyle/smoking
• Aspirin/NSAIDs

Question 7

How do HNPCC cancers differ from normal tumours

Answer 7

In the colon the tumours are more likely to be right sided, histologically more likely to be mucinous and have dense lymphocytic infiltrates

Question 8

What are the main features of HNPCC

Answer 8

Colorectal cancer without extensive polyposis. Endometrial cancer, renal and CNS cancers