Colorectal Pathology Flashcards
what are polyps?
a protrusion above an epithelial surface. it is a tumour (a swelling)
all polyps are adenomas. true or false?
false, but most are
what are the differential diagnoses of a colonic polyp?
- adenoma
- serrated polyp
- polypoid carcinoma
4 other
are all adenomas dysplastic?
yes
what is the sequence of adenoma-carcinoma of polyps?
normal mucosa –> adenoma (dysplastic) –> adenocarcinoma (invasive)
why should all adenomas be removed?
they are ALL premalignant
what are Dukes staging?
- Dukes A: confined by muscularis propria
- Dukes B: through muscularis propria
- Dukes C: metastatic to lymph nodes
left sided colorectal carcinoma
- 75%
- rectum, sigmoid, descending
- Blood PR, altered bowel habit, obstruction
right sides colorectal carcinoma
- 25%
- caecum, ascending
- anaemia, weight loss
describe the pathology of the large bowel with colorectal carcinoma
- varied gross appearance (polypoid, stricturing, ulcerating)
- typical histopathological appearance (adenocarcinomas)
what is the pattern of spread of colorectal carcinoma?
- local invasion: mesorectum, peritoneum etc
- lymphatic spread: mesenteric nodes
- haematogenous: liver, distant sites
whats the visual difference between hereditary and familial cancer?
- hereditary: non polypoid (<100 polyps)
- familial: adenomatous, polypois (FAP) (>100 polyps)
whats the genetic traits in hereditary cancer?
- late onset
- autosomal dominant
- defect in DNA mismatch repair
- inherited mutation in MLH-1, MSH-2, PMS-1 or MSH-6 gene
- right sided
mucinous tumours
Crohn’s like inflammation - associated with gastric and endometrial carcinoma
whats the genetic traits in familial cancer?
- early onset
- autosomal dominant
- defect in tumour suppression
- inherited mutations in FAP gene
- throughout colon
- adenocarcinomas NOS
- no specific inflam response
- asscciated with desmoid tumours and thyroid carcinomas
