Pathology of the Colorectal Carcinoma Flashcards Preview

Gastro > Pathology of the Colorectal Carcinoma > Flashcards

Flashcards in Pathology of the Colorectal Carcinoma Deck (43):
1

What is a polyp?

A protrusion above an epithelial surface

2

Is a polyp benign or malignant?

Can be either

3

What are some examples of benign epithelial polyps

Neoplastic (adenoma inflammatory IBD)
Hamartomatous (juvenile polyp )

4

What is a type of malignant epithelial polyp?

Polypoid (adenocarcinomas or carcinoid polyps

5

What are the 3 different types of macroscopic

Pedunculated
Sessile
Flat

6

Describe pedunculated polyps

Hangs on a long stalk form the mucosa and is mushroom like- easy to remove

7

Describe sessile polyps

Carpet like - difficult to cut out as over a longer area

8

What is dysplastic epithelial lining

Epithelium that has failed to mature

9

Describe adenomas of the colon

Benign tumours which are not invasive and have the potential to develop into cancers

10

How can we reduce the risk of cancer?

Screen the colon and remove all adenomas

11

What are the 3 different microscopic architecture variability

Tubullovillous (tree like)
Tubular (large circles)
Villous (Finger like projections)

12

What are all adenomas?

Dysplastic

13

What can happen if adenomas are left?

They can lead to cancer

14

Describe the adeoma-carcinoma sequence

Normal mucosa,
adenoma (dysplastic)
Adenocarcinoma (invasive)

15

Why must all adenomas be removed?
How is this done?

Because they are all premalignant
Either done endoscopically or surgically

16

Do all colorectal adenomas have the same molecular genetic origins?

No

17

What causes the variation in colorectal adenomas

separate pathways for injerited tumours
Sparate pathways for serrated adenomas

18

What is the primary treatment in most cases of adenocarinoma of the large bowel

Surgery

19

How is the tumour staged?

Endoscopic biopsy sent to pathology

20

Why are gland cells formed?

They are derived from stem cells which give rise to large colonic crypts which still contain traces of normality

21

How does cancer spread to the serosal fat?

Invades through the muscle

22

How do we stage colorectal carcinoma

Using Duke's staging

23

What are the 3 stages of Duke's staging?

Dukes A: Confined by muscularis propria
Dukes B: Through muscularis propria
Dukes C: Metastatic to lymph nodes

24

Where are most colorectal carcinomas found?

75% Left side (rectum,sigmoid descending)
25% Right side (Caecum, ascending)

25

What are the common presentations of left sided colorectal carcinomas?

Blood PR, Altered bowel habit and obstruction

26

What are the common presentations of right sided colorectal carcinomas

Anaemia, weight loss
No PR bleeding

27

Why do some tumours appear to be glistening?

Due to the mucous which is produced from the tumour

28

What might be affected by local invasion

Mesorectum, peritoneum, other organs such as the bladder, ovary or prostate, uterus or vagina

29

What might be affected by lymphatic spread

Mesenteric nodes

30

What might be affected by haematogenous

Liver, distant sites

31

Where is the most common site of metastases from colorectal cancer and why?

Liver
Due to the hepatic portal system

32

What are the two types of inherited cancer syndromes?

Heriditary Non Polyposis Coli (HNPCC)
Familial Adenomatous Polyposis (FAP)

33

How many polyps are present in HNPCC

<100

34

How many polyps are present in FAP

>100 polyps

35

Describe the genetics of HNPCC FAP

Autosomal dominant

36

What may be required for patients in FAP

removal of the colon and rectum at a young age

37

Describe the onset for HNPCC and FAP

HNPCC - Late
FAP - Early

38

What causes HNPCC

Defect in DNA mismatch repair

39

What causes FAP

Defect in tumour supression

40

Where do HNPCC tumours arise

Right side

41

Where do FAP tumours arise

Throughout the entire colon

42

What is HNPCC associated with

Gatric and endometrial carcinoma

43

What is FAP associated with?

Desmoid tumours and thyroid carcinoma

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