51. Polyposis syndromes

Question 1

polyposis syndromes -types

Answer 1

1. familiar adenomatous polyposis (FAP)
2. Gardner syndrome
3. Turcot syndrome
4. Peutz - Jeghers syndrome
5. Juvenile polyposis syndrome

Question 2

familiar adenomatous polyposis - mechanism / age / location

Answer 2

AD mutation of APC tumor suppressor gene on chromosomal 5q (2hit hypothesis) –> thousands of polyps arise starting after puberty –> pancolinic, always involves rectum

Question 3

familiar adenomatous polyposis - management

Answer 3

prophylactic colectomy or else 100% progress to CRC

Question 4

Gardner syndrome ?

Answer 4

FAP + osseus and soft tissue tumors, congenital hypertrophy of retinal pigment epithelium, impacted / supernumenary teeth

Question 5

Turcot syndrome

Answer 5

FAP + malignant CNS tumor

Question 6

Peutz- Jeghers syndrome - definition/ mode of inheritance/ presentation

Answer 6

AD syndrome featurig with numerous hamartomas thoughout GI tract, along with hyperpigmented mouth, lips, hands, genitalia

Question 7

Peutz- Jegjers syndrome - cancer

Answer 7

increased risk of breast and GI cancers ( eg. CR, stroma, small, pancreas)

Question 8

Juveniles polyposis syndrome - definition/ mode of inheritance / presentation

Answer 8

AD syndrome in children ( typically under 5) featuring with numerous polyps in large and small intestine, stomach

Question 9

Juvenile polyposis syndrome - cencer

Answer 9

increased risk of CRC

Question 10

SPoradic juvenile poly ( if solitary lesion) - manifestation

Answer 10

solitary rectal poly that prolapses and bleeds

Question 11

• A 12-year-old boy is found to have several polyps in his colon, stomach, and small bowel. For what cancer is he at risk?

Answer 11

Adenocarcinoma (this is likely juvenile polyposis syndrome)

Question 12

• A man has GI tract hamartomas and dark patches around his mouth and palms. He asks if his son will be affected by this disorder. Your reply?

Answer 12

The probability is 50% (this patient has Peutz-Jeghers syndrome, an autosomal dominant disorder)

Question 13

• A patient has multiple GI tract hamartomas and hyperpigmented hands, mouth, lips, and genitalia. What cancers is he at increased risk for?

Answer 13

Increasing risk for colorectal, breast, stomach, small bowel, pancreatic cancers (the patient has Peutz-Jeghers syndrome

Question 14

• A patient inherits a mutation of the APC gene on chromosome 5q. He asks about his risk for colorectal cancer. What do you tell him?

Answer 14

The patient has familial adenomatous polyposis syndrome; there is 100% progression to CRC if the colon is not removed

Question 15

• A 28-year-old man with a history of familial adenomatous worries about his newborn son and asks what the inheritance pattern is.

Answer 15

Autosomal dominant (patients inherit one faulty copy of the gene and lose the other through an acquired mutation [two-hit hypothesis])

Question 16

• Familial adenomatous polyposis involves mutation of the ____ gene on chromosome ____. This disease follows the ____ hypothesis.

Answer 16

APC, 5q; two-hit

Question 17

• You are going to perform a colonoscopy on a patient with familial adenomatous polyposis. What do you expect to find? Is the rectum involved?

Answer 17

Thousands of polyps (pancolonic involvement) (always involving the rectum)

Question 18

• A patient with bone and soft tissue tumors is found to have thousands of polyps on colonoscopy. What syndrome is suspected?

Answer 18

Gardner syndrome

Question 19

• Why might you want to perform a colonoscopy on a young patient with extra teeth and abnormally pigmented retinas?

Answer 19

These are Gardner syndrome traits (FAP, osseous/soft tissue tumors, hypertrophy of retinal pigment epithelium, impacted/supernumerary teeth)

Question 20

• A young patient with a history of a brain tumor has GI bleeding. What syndrome might you want to urgently screen for in your work-up?

Answer 20

Turcot syndrome (FAP + malignant CNS tumor) (Turcot = Turban)

Question 21

• What is the inheritance pattern of juvenile polyposis syndrome? At what age does it typically present?

Answer 21

Autosomal dominant; less than 5 years of age