Colon

Question 1

Peutz-Jeghers

Answer 1

Autosomal dominant gemline mutation in the STK11 (LKB1)
Serine threonine Kinase
(LKBA) mapped to chromosome 19p 13.3
pigmented moco cutaneous macules
multiple hamartomatous GI polyps
^risK for cancer:
- GI Ca
CRC -39%
Stomach - 29%
SB - 13 %
Pancreas 11-36%
- Extra -intestinal ca.
Lung
Breast /uterine/cervical
Ovary/testicular
Screening starts at
8-10 SB, testicular ovarian
Late teens CRC Stomach
From 18 uterine and cervical ca
From 25 breast ca

Question 2

What percentage of cases of colorectal cancer are due to FAP?

Answer 2

1%
Surveillance
FAP starts at 10-12 every year
AFAP starts at 18-20 every year
Depends on the number and size of polyps
Those with ileorectal anastomosis (IRA) need more frequent follow-ups
Post-surgery f-up every 6-12 months
Polyps to my or APC
Terminal ileostomy if more cancer develops

Question 3

After colorectal cancer, for which of the following cancers is the lifetime risk highest in patients with FAP?

Answer 3

Duodenal periampullary cancer

Question 4

What number of colorectal adenomas is needed to make a clinical diagnosis of FAP in a patient who has a family member with the syndrome?

Answer 4

<100

Question 5

By how many years is the development of polyps and cancer delayed in patients with AFAP compared with classic FAP?

Answer 5

10 years

Question 6

Which of the following criteria is used to diagnose serrated polyposis syndrome?

Answer 6

At least 5 serrated polyps proximal to the sigmoid colon, of which at least 2 measure 10 mm or more
Any number plus first degree family
More than 20 thought the colon
Screen from 40 or the same age as the youngest SPS and every 5 years
Colonoscopy every 3-5 years to remove polyps
Surgery if uncontrolled or ca. Colectomy with IRA

Question 7

Which of the following is a type of PTEN hamartoma tumour syndrome?

Answer 7

Bannayan-Riley-Ruvalcaba Sd
Cowden disease

Start screening colonoscopy by 35-y or 5-10 years before the earliest ca in the family and
Annual mammogram by 30-y and thyroid US at diagnosis

Question 8

Where in the gastrointestinal tract are hamartomas most frequently found in patients with Peutz-Jeghers syndrome?

Answer 8

SB»colon»rectum
Smooth muscle prominent in the lamina propria

Question 9

Which of the following clinical features is an associated manifestation of juvenile polyposis syndrome?

Answer 9

Congenital heart disease Bone swelling and macrocephaly
Colon 98% and rectum commonest, also in stomach, pancreas and SB
Hereditary hemorragia telangiectasia (HHT)
Criteria; 3-5 in the colon, multiple in the GI tract, any number + family hx
Genes BMPR1A 10q and SMAD4 18q(HHT) both involved in TGF-B signalling
Start screening with Colo+OGD from 15s
Every 1-3 years

Question 10

When should small bowel screening begin in patients with Peutz-Jeghers syndrome?

Answer 10

8-10 years of age

Question 11

Mutations in which gene are known to be responsible for FAP and AFAP?

Answer 11

APC