tutorial 12 - colorectal cancer Flashcards
What is the most common type of cancer in the colon and rectum?
Adenocarcinoma
What are some common symptoms of colorectal cancer?
tenesmus, diarrhoea, constipation, blood in stools, anaemia, weight loss
What genetic condition results in many (100+) polyps developing in the colon?
Familial Adenomatous Polyposis
What type of tumor do colorectal adenocarcinomas usually arise from?
Colonic adenomas/adenomatous polyps
What is a predunculated polyp?
A polyp that has a stalk, meaning it can stick out from the mucosa
What are sessile polps?
Polyps that are stuck on the colonic mucosa without a stalk/neck
What are the 3 histological classifications of colonic adenoma?
Tubular, Villous, Tubulo-villous
What are the histological features of a tubular adenoma?
glands form rounded tubules in the polyp
What are the histological features of a villous adenoma?
Glands have finger like-villi formed of glands.
What are the histological features of dysplastic glands in colonic adenomass?
Glands appear darker due to enlarged hyper-chromatic nuclei, and have reduced numbers of goblet cells which are usually lightly stained.
What change must occur in a adenomatous colon polyp for it be considered malignant (adenocarcinoma)?
Glands must invade beyond the muscularis mucosae and into the submucosa. If the polyp has a stalk, the glands must invade past the stalk.
What are the 3 most common patterns of gross morphology of colorectal adenomcarcinomas?
Exophytic fungating (‘cauliflower’), ulcerative, diffusely infiltrative
What is a exophytic fungating colorectal adenocarcinoma?
A tumour that projects into the lumen
What is a diffusely infiltrative colorectal adenocarcinoma?
Tumour causes diffuse thickening of the lumen, causing an annular/apple core/napkin-ring carcinoma
What are the histological changes observed as a colonic adenocarcinoma becomes less differentiated?
Decrease and eventual diasppearance of glands
