Lower GI Pathology

Question 1

mot common congen GI abn

Answer 1

Hirschsprung’s disease (in male babies)

Question 2

path of hirschprungs disease

Answer 2

absence of ganglion cell in myenteric plexus -> distal colon fails to dilate

Question 3

how will Hirschsprung disease present

Answer 3

failure to pass meconium in first 48hr
abdo distention
overflow diarrhoea

Question 4

diagnostic inv for hirschprungs d

Answer 4

full thickness biopsy of affected segment

Question 5

treatment of hirschprungs d

Answer 5

resection of affected segment

renalanastamosis

Question 6

what causes pseudomembranous colitis

Answer 6

c diff inf (antibiotic asso)

Question 7

histopath of pseudomembranous colitis

Answer 7

pseudomembrane formation on colon

Question 8

diagnostic inv for pseudomembranous colitis

Answer 8

toxin stool assay

Question 9

Treatment for pseudomembranous colitis

Answer 9

side room
vancomycin
metronidazole

Question 10

histopath of ischaemic colitis

Answer 10

watershed zones of disease on splenic flexures and rectrosigmoid

Question 11

causes of ischaemic colitis

Answer 11

occlusive - a/v occlusion, sml vessel disease, obstruction (hernia)
hypoperfusion - CHF, haemorrhagic shock

Question 12

presentation of crohn’s

Answer 12

affects entire GIT, transmural inflam, patchy
non-caesating granulomas
skip lesions
cobblestone mucosa
ulcers/fissures/abscesses
thick bowel wall

Question 13

presentation of UC

Answer 13

continuous inflam in rectum and colon
limited to mucosa]shallow ulcers
normal thickness bowell wall

Question 14

what are some complications of UC

Answer 14

toxic megacolon, adenocarcinoma

Question 15

what are the extra-intestinal signs of IBD

Answer 15

arthritis, uveitis, erythema nodosum, polyderma gangrenosum

Question 16

what features of polys are asso with inc risk of malig

Answer 16

inc in size and dysplasia

Question 17

what is the most common type of colorectal cancer

Answer 17

adenocarcinoma

Question 18

what are the RFs for colorectal cancer

Answer 18

low fibre, high fat diet, obese, chronis IBD

Question 19

what is the dukes staging for colorectal cancer

Answer 19

A = only mucosa
B = no lymph node inv
C = LN inv
D = distant mets

Question 20

what is the inheritance of Familial adematous polyposis

Answer 20

auto dom
due to apc tumour suppressor gene mut
100% chance of cancer in 10-15y

Question 21

what is gardeners syndrome

Answer 21

Auto dom

FAP with extra intestinal malformations (esp dental)

Question 22

what is HNPCC/lynch syndrome

Answer 22

colonic cancer + another extra colonic cancer at the same time