Flashcards in 51. Polyposis syndromes Deck (21):
polyposis syndromes -types
1. familiar adenomatous polyposis (FAP)
2. Gardner syndrome
3. Turcot syndrome
4. Peutz - Jeghers syndrome
5. Juvenile polyposis syndrome
familiar adenomatous polyposis - mechanism / age / location
AD mutation of APC tumor suppressor gene on chromosomal 5q (2hit hypothesis) --> thousands of polyps arise starting after puberty --> pancolinic, always involves rectum
familiar adenomatous polyposis - management
prophylactic colectomy or else 100% progress to CRC
Gardner syndrome ?
FAP + osseus and soft tissue tumors, congenital hypertrophy of retinal pigment epithelium, impacted / supernumenary teeth
FAP + malignant CNS tumor
Peutz- Jeghers syndrome - definition/ mode of inheritance/ presentation
AD syndrome featurig with numerous hamartomas thoughout GI tract, along with hyperpigmented mouth, lips, hands, genitalia
Peutz- Jegjers syndrome - cancer
increased risk of breast and GI cancers ( eg. CR, stroma, small, pancreas)
Juveniles polyposis syndrome - definition/ mode of inheritance / presentation
AD syndrome in children ( typically under 5) featuring with numerous polyps in large and small intestine, stomach
Juvenile polyposis syndrome - cencer
increased risk of CRC
SPoradic juvenile poly ( if solitary lesion) - manifestation
solitary rectal poly that prolapses and bleeds
• 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?
Adenocarcinoma (this is likely juvenile polyposis syndrome)
• 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?
The probability is 50% (this patient has Peutz-Jeghers syndrome, an autosomal dominant disorder)
• A patient has multiple GI tract hamartomas and hyperpigmented hands, mouth, lips, and genitalia. What cancers is he at increased risk for?
Increasing risk for colorectal, breast, stomach, small bowel, pancreatic cancers (the patient has Peutz-Jeghers syndrome
• 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?
The patient has familial adenomatous polyposis syndrome; there is 100% progression to CRC if the colon is not removed
• A 28-year-old man with a history of familial adenomatous worries about his newborn son and asks what the inheritance pattern is.
Autosomal dominant (patients inherit one faulty copy of the gene and lose the other through an acquired mutation [two-hit hypothesis])
• Familial adenomatous polyposis involves mutation of the ____ gene on chromosome ____. This disease follows the ____ hypothesis.
APC, 5q; two-hit
• You are going to perform a colonoscopy on a patient with familial adenomatous polyposis. What do you expect to find? Is the rectum involved?
Thousands of polyps (pancolonic involvement) (always involving the rectum)
• A patient with bone and soft tissue tumors is found to have thousands of polyps on colonoscopy. What syndrome is suspected?
• Why might you want to perform a colonoscopy on a young patient with extra teeth and abnormally pigmented retinas?
These are Gardner syndrome traits (FAP, osseous/soft tissue tumors, hypertrophy of retinal pigment epithelium, impacted/supernumerary teeth)
• 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?
Turcot syndrome (FAP + malignant CNS tumor) (Turcot = Turban)