Tumours of the Colon Flashcards
What are the two kinds of growths that can be sen in the colon?
Polyps and carcinomas
What are the two kinds of polyps?
Non neoplastic and neoplastic polyps
What are examples of non neoplastic polyps and how are they formed?
Hyperplastic polyps: benign; gland with intraluminal folds; sessile
Inflammatory: benign, seen in IBD
formed as a result of abnormal mucosa maturation or inflammation
What are examples of neoplastic polyps and how are they formed?
Adenomas: benign polyps with malignant potential, can have a familial predisposition.
It is epithelial proliferation with degrees of dysplasia
What are the three types of adenomas?
Tubular: most common, tubular glands
Villous: villous projections (sessile)
Tubulovillous: mixture of ^^
What are polyps like clinically?
Typically asymptomatic, can bleed. Of larger can cause bowel obstruction
How can we suspect adenoma to adenocarcinoma change?
Larger polyps, severe dysplasia, high in villous adenomas
What are clinical features of colorectal cancer?
abdominal pain, mucous discharge, bleeding, altered bowel habits, bowel obstruction, weight loss.
Right sided cancers can cause occult bleeding, meaning iron deficiency anaemia
What is familial polyposis syndrome?
A syndrome where an individual is prone to developing many polyps, usually of a certain type.
What is the most well know FPS?
Familial adenomatous polyposis, where there are multiple adenomas that will turn into cancer.
Is a defect of the APC gene (a tumour suppressor gene) of chromosome 5 and patients will get a prophylactic colectomy
What is HNPCC?
heriditary nonpolyposis colorectal cancer
autosomal dominant inheritance, where adenomas turn into carcinomas but no increase in polyps
inherited mutations that impair DNA mismatch repair
