Colorectal Pathology Flashcards
What benign polyps can arise in the large bowel?
FROM EPITHELIUM
- adenomas
- polyps from inflammatory disease
- hamartomas (juvenile polyp, Peutz-Jeghers)
FROM MESENCHYMA
- lipoma
- lymphangioma
- haemangioma
- fibroma
- leiomyoma
What malignant polyps can arise in the large bowel?
- polypoid adenocarcinomas
- carcinoid polyps
- sarcomas
- lymphomatous polyps
Describe the different macroscopic shapes of polyps in the large bowel?
- pedunculated
- sessile
- flat
The microscopic architecture of adenomas can vary in the bowel. GIve examples of how they can appear on histology?
- Tubular
- Villous
- Mixture of both => Tubullovillous
All adenomas are dysplastic. TRUE/FALSE?
TRUE
All adenomas must be removed. TRUE/FALSE?
TRUE
- premalignant => can transform into adenocarcinoma
How do colorectal tumours appear macroscopically?
ulcerating and stricturing mass
What types of fat can colorectal tumours invade locally?
- pericolic fat
- serosal fat
Describe the Duke staging of colorectal cancer
Dukes A: Confined by muscularis propria
Dukes B: Through muscularis propria
Dukes C: Metastatic to lymph nodes
Compare the prognosis of each Duke’s staging using 5 year survival?
A - 90%
B - 70%
C - 35%
Do colorectal carcinomas more commonly appear on the RIGHT or LEFT side of the large bowel?
75% Left sided (rectum, sigmoid, descending)
25% Right sided (Caecum, Ascending)
What are the common presenting complaints when patients have a left sided colorectal cancer?
Blood PR
Altered bowel habit
Obstruction
What are the common presenting complaints of a right sided colorectal cancer?
Anaemia
Weight loss
Colorectal cancers commonly metastasise to what organ?
Liver
What inherited syndromes can cause colorectal cancers?
Heriditary Non Polyposis Colorectal Cancer (HNPCC)
<100 polyps usually present
Familial Adenomatous Polyposis (FAP)
>100 polyps present
When does HNPCC usually present and what genetic mutations cause this?
- Late onset
- Autosomal dominant
- Defect in DNA mismatch repair
- Mutation in MLH-1, MSH-2, PMS-1 or MSH-6 genes
When does FAP usually present and what genetic mutations cause this?
- Early onset
- Autosomal dominant
- Defect in tumour supression
- Inherited mutation in FAP gene
Tumours related to HNPCC commonly occur on the RHS of the colon. TRUE/FALSE?
TRUE
- tumour related to FAP occur throughout the colon in comparison
What type of tumours occur in HNPCC and what other cancers is the condition linked to?
- Mucinous tumours
- Assoc. with gastric and endometrial carcinoma
FAP is associated with what other cancers?
- desmoid tumours
- thyroid carcinoma
An inflammatory response is seen in HNPCC but not FAP. TRUE/FALSE?
TRUE
- similar to inflammation in Crohn’s disease
