Lower GI disease Histopath

Question 1

Commonest place to find diverticulitis

Answer 1

sigmoid colon

Question 2

pseudodiverticuli

Answer 2

do not have all layers of the bowel wall

Question 3

complications fo diverticular disease

Answer 3

pain
diverticulitis
gross perforation
fistula a(bowel, bladder, vagina)
obstruction

Question 4

Inflammatory disorders of the large bbowel

Answer 4

acute colitis
- radiotherapyu

chronic colitis
- crohns

Question 5

Causes of infective colitis

Answer 5

viral e.g. CMV
bacterial e.g. salmonella
protozoal e.g/ entamoeba hystolytica
fungal e.g. candida

Question 6

pseudomembranous colitis

Answer 6

follows abx therapy
acute colitis with pseudomembrane formation
caused y protein exotoxins of C diff
histology: characteristic microscopic features on biopsy
lab: c diff toxine stool assay

Question 7

pseudomembranous colitis

Answer 7

pseudo because later is a pseudomembrane made of inflammatory tissue (rather than normal lining)

Question 8

Vascular disorders of lower bowel

Answer 8

ischaemic colitis/infarcion
- can be acute or chronic
usually occurs In segments in watershed zones e.g. scenic flexure

??also: rectosigmoid (IMA to internal iliac)

Question 9

Aetiology of ischaemic colitis

Answer 9

arterial occlusion: atherosclerosis

can also occur in low flow states e.g. due to hypovolaemic shock

obstruction

Question 10

macroscopic appearance of bowel ischaemia

Answer 10

red, ischeamic

Question 11

IBD

Answer 11

Crohn’s disease and Ulcerative colitis

in the real world there is also indeterminate colitis

Question 12

IBD RFs

Answer 12

genetic predisposition
infection (mycobacteria, measles)
abnormal host immunoreactivity
microbiome

Question 13

Path features of Crohns diseaase

Answer 13

skip lesions
mouth to anus
TRANSMURAL INFLAMMATION
fissure, sinus, fistula formation
non-caseating granulomas
cobblestone mucosa

Question 14

extra intestinal manifestations of crohns diseases

Answer 14

arthriris
uveitis
stomatitis/cheilitss
skin diseases (erythema nodosum, ….)

Question 15

UC

Answer 15

starts in rectum and colon in contiguous fashion
may see mild backwash ileitis and aappendiceaal involvement but small bowel and
shallow ulcers

…..

Question 16

Complications of UC

Answer 16

toxic megacolon
severe haemorrhage
adenocarcinoma (20-30% x risk)

Question 17

extra intestinal manifestations of UC

Answer 17

arthritis
myositis
uveitis/iritis
erythema nodosum
pyoderma gangrenosum
primary sclerosis cholangitis (5.5% in pancolitis)

Question 18

UC - what cancers are you at increased risk of?

Answer 18

cholangiocarcinoma
adenoacarcinoma

Question 19

What organ has the highest amount of neuroendocrine cells?

Answer 19

bowel

Question 20

Commonest tumours of the lower GI

Answer 20

non-neoplastic polyps
neoplastic epithelial lesions
- adenoma
- adenocarcinoma

Question 21

Types of tumours of the colon and rectum

Answer 21

polyps (non-neoplastic)
hyperplss

xxxx
xxx

Question 22

Peutz Jeghers

Answer 22

AD inherited syndrom

polyps and pigmentation of the lips and other mucocutaneous surfaces e.g. genitals

increased risk of bowel cancer, other GI cancers

Question 23

Adenomas of the colon and recutm

Answer 23

tubular adenoma
tuboviolous adenoma
villous adenoma

Question 24

prevalence of adenomas of the colon

Answer 24

///

Question 25

tubular adenomas

Answer 25

usually round
can have a stalk (pedunculated polyps)

Question 26

villous adenoma

Answer 26

xxx

Question 27

tubovillous adenoma

Answer 27

have features of tubular and villous adenomas

Answer 28

• the more villous, the greater the risk of cancer

Question 29

Why is diverticular disease common in the west?

Answer 29

low fibre diet

Question 30

Sx of colon adenomas

Answer 30

usually none

bleeding/anaemia

Question 31

Familial syndromes for adenocarcinoma of the colon

Answer 31

pouty jeghers
FAAP (familial adenomatous polyposis (gardner’s, turoct))
HNPCC

Question 32

What is commoner, FAP or HNPCC?

Answer 32

HNPCC

Question 33

FAP - hereditary pattern?

Answer 33

AD

Question 34

average onset of FAP?

Answer 34

25

Question 35

Genetic mutation in FAP

Answer 35

5q21, APC tumour suppressor gene

Question 36

Mx in FAO

Answer 36

prophylactic colon removal

but still risk of duodenal periampullary Ca, monitor duodenum well

Question 37

What is Gardner’s syndrome

Answer 37

FAP with extra intestinal manifestations

(osteomas, demoed tumours)

Question 38

What is Turcot’s syndrome

Answer 38

FAP with ???

Question 39

hereditary pattern of HNPCC

Answer 39

AD

Question 40

What happens in FAP?

Answer 40

hundreds, thousands of polyps

Question 41

HNPCC - stats and what happens

Answer 41

may have polyps
3-5% of all colorectal cancers
eat leases 1 of 4 DNAA mismatch repair genes involved.

Question 42

HNPCC - where are the colonic cancers most common?

Answer 42

in caecum

Question 43

what cancers are HNPCC associated with?

Answer 43

colon
endometrium
prostate
breast
stomach

multiple synchronous cancers

Question 44

Commonest colorectal Ca?

Answer 44

98% are adenocarcinoma

Question 45

Age in colorectal carconoma

Answer 45

60-79 yo

if <50 consider familial syndrome

Question 46

aetiology of colorectal carcinoma

Answer 46

familial
diet (low fibre, high fat etc)
lack of exercise

… insert

Question 47

Grading and staging of colorectal cancer

Answer 47

grade - degree of differentiation
Stage - TNM

Question 48

TNM - what are the different Ts in colorectal carcinoma?

Answer 48

T1 - submucos
T2 - muscle
T3
T4 - peritoneum

Question 49

what sort of colon polyps most commonly periscope to adenocarcinoma of the colon?

Answer 49

villous adenoma