Large intestine neoplasms Flashcards
What are the two types of colonic polyps? Where do each occur
hyperplasic - hyperplasia, benign
-left colon - rectosigmoid
adenomatous - neoplastic
-rectosigmoid
What are the mutations that are needed for a polyp to turn malignant?
APC –> KRAS –> P53
What are three factors of a polyp that may indicate it will progress from an adenoma to a carcinoma?
- size >2 cm
- sessile growth - flat
- villous (not tubular)
What is FAP?
auto dominant mutation of APC –> 1000s of polyps
What is the treatment for FAP?
colon and rectum are removed
What is gardeners syndrome ?
FAP, fibromatosis, osteomas
What is Turcot syndrome?
FAP , CNS tumors - medulloblastoma, glial tumors
When would a juvenile polyp occur? Are they malignant?
children <5
no0O0OOope they are benign
How does juvenile polyposis differ from a juvenile polyp?
there is an inc risk of progression to carcinoma since there are so many of them
What is peutz jeghers syndrome?
hamartomatous polyps throughout GI tract
mucocutaneous hyperpigmentation
When is the peak incidence of colorectal carcinoma?
60-70 years old
What is HNPCC? What cancers does it inc the risk of?
inherited mutation in DNA mismatch repair enzymes
- early age
- inc risk for colorectal, ovarian and endometrial carcinoma
When and how does screening occur for colorectal cancer?
begins at 50 years of age
colonoscopy - remove all polyps, test for occult blood
How does a left sided carcinoma differ from a right sided?
left sided “napkin ring lesion” - dec stool caliber
Right - iron deficiency anemia and vague pain
What infection is strongly associated with colorectal cancer?
Strep bovis endocarditis
