Small & Large Bowel Tumours and Polyps

Question 1

What are examples primary small bowel tumours?

Answer 1

Lymphomas
Carcinoid tumours (most common in appendix)
Carcinomas

Question 2

Carcinomas of the small bowel are associated with?

Answer 2

Crohn’s Disease

Question 3

What are features of lymphomas of the small bowel?

Answer 3

Rare
All non-Hodgkins
Maltomas (B-cell derived) 
Rarely enteropathy associated T-cell lymphomas 
Associated with Coeliac's disease

Question 4

What are common sources of secondary tumours (metastases) to the small bowel?

Answer 4

Ovary
Colon
Stomach (more common)

Question 5

What is a polyp?

Answer 5

Protrusion above an epithelial surface (easily removed tumour)

Question 6

What is the macroscopic appearance of a polyp?

Answer 6

Pedunculated, sessile, fat, irregular surface

Question 7

What is the microscopic appearance of a polyp?

Answer 7

Tubulo-villous

Question 8

How do you distinguish between an adenoma and a polyp?

Answer 8

Histopathology

Question 9

Adenomas are at high risk of?

Answer 9

Malignant transformation

Question 10

All adenomas are?

Answer 10

Pre-malignant (dysplastic)

Question 11

What is HNPCC?

Answer 11

Hereditary non-polyposis colorectal cancer

Question 12

How many polyps are found for HNPCC?

Answer 12

<100

Question 13

What are features of HNPCC inheritance and onset?

Answer 13

Late onset
Autosomal dominant
Defect in DNA mismatch repair

Question 14

What are features of the tumours of HNPCC?

Answer 14

Right sided, mutinous tumours
Crohn’s like inflammatory response
Associated with gastric and endometrial carcinoma

Question 15

How do you investigate HNPCC?

Answer 15

Surveillance - colonoscopy every 2 years from age 25 - upper GI endoscopy from age 50

Question 16

HNPCC is managed the same way as?

Answer 16

Colorectal Cancer

Question 17

What is FAP?

Answer 17

Familial andenomatous polyposis

Question 18

How many polyps are found with FAP?

Answer 18

> 100

Question 19

What are features of the inheritance of FAP?

Answer 19

Early onset
Autosomal dominant
Defect in tumour suppression

Question 20

What are features of the tumours of FAP?

Answer 20

Throughout colon
Adenocarcinoma NOS (nitrous oxide system)
No specific inflammatory response
Associated with desmoid tumours and thyroid caricnom

Question 21

How does a colonic polyp present?

Answer 21

Rectal bleeding
Diarrhoea
Abdominal pain
Mucous discharge

Question 22

How do you treat colonic polyps?

Answer 22

Remove (endoscopically / surgically)

Send biopsy to pathology

Question 23

Which mutation allows transition from normal epithelium to small adenoma?

Answer 23

APC

Question 24

Which mutation allows transition from small to large adenoma?

Answer 24

K-ras

Question 25

Which mutations allow transition from large adenoma to invasive adenocarcinomas?

Answer 25

p53 | chromosome 17p, 18q deletion

Question 26

Which mutation allows an invasive adenocarcinoma to metastasise?

Answer 26

nm23 deletion

Question 27

What are risk factors for colorectal cancer?

Answer 27

``` FHx IBD FAP AFAP HNPCC Nulliparity Late age at 1st pregnancy Early menopause Western diet Smoking Obesity Alcohol intake Diabetes ```

Question 28

What is nulliparity?

Answer 28

Never having given birth

Question 29

What predisposes to CRC?

Answer 29

Adenomatous polyps and IBD

Question 30

What are possible macroscopic appearances of CRC?

Answer 30

Polypoidal, annular (stenosing), ulcerative

Question 31

With increasing stage of CRC the microscopic appearance becomes increasingly?

Answer 31

Poorly differentiated

Question 32

Lymphatic spread of CRC is commonly to?

Answer 32

Pericolic and perivascular nodes (need to remove colon + associated vasculature/lymphatics)

Question 33

Haematogenous spread of CRC is first to the _____ then distant sites

Answer 33

liver

Question 34

What are causes of CRC?

Answer 34

Environment (red/processed meat, smoking, alcohol, obesity)

Question 35

What is protective against colorectal cancer?

Answer 35

Vegetables, fibres, and exercise

Question 36

Why is exercise protective against CRC?

Answer 36

Acts on AMPK - same enzyme that tumour suppressors activate to decrease cell turnover and increase glucose uptake by muscle

Question 37

How does CRC present?

Answer 37

``` Weight loss Anaemia Change in bowel habit Abdominal mass Abdominal pain ```

Question 38

What is the distinguishing feature of CRC in the ascending colon?

Answer 38

Anaemia (esp. after menopause)

Question 39

What is the distinguishing feature of CRC in the descending colon?

Answer 39

Mass, hepatomegaly, distension

Question 40

What is the distinguishing feature of CRC in the rectum?

Answer 40

Rectal bleeding | Tenesmus

Question 41

What are general signs of CRC?

Answer 41

Anaemia Cachexia Lymphadenopathy

Question 42

What are abdominal signs of CRC?

Answer 42

Mass Hepatomegaly Distension

Question 43

What are rectal signs of CRC?

Answer 43

Mass | Blood

Question 44

What is an emergency presentation of CRC?

Answer 44

Obstruction (distension, constipation, pain, vomiting) Bleeding Perforation

Question 45

Which investigations can be done for CRC?

Answer 45

``` Barium enema (+/- CT) Colonoscopy +/- biopsy CEA Sigmoidoscopy FOBT ```

Question 46

What is CEA?

Answer 46

Carcinoembryonic antigen - tumour protein marker)

Question 47

What is FOBT?

Answer 47

Faecal output blood testing

Question 48

FOBT is used to?

Answer 48

Screen for CRC

Question 49

If the FOBT screening is positive, patients are invited for?

Answer 49

Colonoscopy

Question 50

How do you treat CRC?

Answer 50

Remove affected part of bowel + associated lymph/vasculature

Question 51

How do you treat CRC obstruction?

Answer 51

``` Colostomy (alone) Colostomy + resection resection + anastomosis Stenting Radiotherapy ```