Nelson: Path Small Intestine, Colon cont. Flashcards
Where do inflammatory polyps occur?
ANYWHERE in GI tract
What is an inflammatory pseudopolyp?
When the area around the “polyp” is ulcerated so the remaining mucosa appears to be a polyp
Most common location for a juvenile (retention) polyp?
Rectum
What mutations may a patient with juvenile polyposis have?
What are they at increased risk of?
SMAD4-encodes a cytoplasmic intermediate of the TGF-Beta signaling pathway) or BMPRIA (a kinase)
Increased risk of adenocarcinoma
Multiple hamartomatous polyps and mucucutaneous hyperpigmentation makes you think of….?
Peutz-Jeghers syndrome (PJS)
Most common location for Peutz-Jeghers polyps?
Small bowel
What mutation may patients with PJS have?
Loss of function mutations of STK11 tumor suppressor
Patients with PJS are at increased risk for what?
GI adenocarcinomas as well as malignancies of other organs such as breast, lung, pancreas, gonads, uterus
*Note: GI tract adenocarcinomas can arise independently of the hamartomatous polyps
How may patients with PJS present in childhood?
GI bleeding
Intussusception
What are the Peutz-Jeghers polyps like?
Smooth muscle pattern, frequently pedunculated.
Most common type of adult colonic polyp?
Hyperplastic polyps
Where are most hyperplastic polyps?
Left colon (rectum)
____________ are neoplastic polyps that are more common in the colon but when they occure in the small bowel they are usually in the ________ of the duodenum.
Adenomas
Ampulla
What two types of proliferation can occur in adenomas?
Tubular
Villous
Adenomas are benign or malignant?
Can be precursors to what?
Benign
Adenocarcinoma
What should be done when an adenoma is discovered?
NEEDS TO BE COMPLETELY REMOVED
Primary location for sessile serrated polyps?
right colon
What chance occurs in a sessile serrated polyp for it to be considered to have low grade dysplasia?
Adenomatous type epithelial change! Dysplastic glandular proliferation
Describe the inheritance of Familial Adenomatosis Polyposis (FAP).
Autosomal dominant
Mutation in the APC tumor suppressor gene
Patients inherit a single APC mutation and then acquire a second –> resulting in adenomas
What is the risk of colorectal adenocarcinoma in patients with FAP?
100 % risk
How is FAP diagnosed?
Clinical presentation: >100 polyps, detection of germline mutations of the APC gene
What can be seen on the ophthalmic exam in many patients with FAP?
Congenital hypertrophy of the pigmented retinal epithelium