large intestine tumours Flashcards
(48 cards)
what is a colonic polyp
an abnormal growth of tissue projecting from the colonic mucosa
what is the precursor lesion in most colon cancer
adenomas
what type of inheritance is colon cancer
autosomal dominant
what is an adenoma
benign, dysplastic tumour of columnar cells or glandular tissue
what do polyps in the rectum and sigmoid present with
rectal bleeding
diagnosing polyps
- barium enema
- CT colonography
- colonoscopy
what do large villous adenomas present with
profuse diarrhoea with mucus and hypokalaemia
what happens when polyps are found
remove them with endoscopically
what are sessile adenomas characterised by
saw-tooth appearance of the crypt epithelium
what do right sided colorectal cancers originate from
sessile serrated adenomas
what kind of inheritance is FAP
autosomal dominant
what mutations causes FAP
APC gene
how many polyps is there in FAP
hundreds to thousands of colorectal and duodenal adenomas
treatment of FAP
- colectomy
- olirectal anastomosis
which side of the colon do FAP polyps reside
right side
another name for Lynch syndrome
HNPCC
what mutation causes HNPCC
DNA mismatch repair genes
MLH1
what are DNA mismatch repair genes responsible for
maintaining the stability of DNA during replication
what is the inheritance for HNPCC
autosomal dominant
where are the polyps in HNPCC
right side
where else can HNPCC occur
- stomach
- small intestine
- bladder
- skin
- brain
what are female patents at risk for in HNPCC
endometrial and ovarian cancer
how is diagnosis of HNPCC made
from family history of colon cancer at a young age
what is Turcot syndrome
FAP or lynch with brain tumour
