Colorectal pathology Flashcards Preview

GI lectures > Colorectal pathology > Flashcards

Flashcards in Colorectal pathology Deck (26)
Loading flashcards...
1
Q

what is a poly?

A

protrusion above the epithelial surface
type of tumour (swelling)
can be benign or malignant

2
Q

all polyps are adenomas, true or false?

A

false

3
Q

what are the 4 differential diagnoses of a colonic poly?

A
adenoma
serrated polyp
polypoid carcinoma
other
distinguished via histopathoogy
4
Q

what 3 types of polyp can you get macroscopically?

A

pedunculated (dangling)
sessile (spongey)
flat
type determines how they can be removed

5
Q

what can polyps look like macroscopically?

A

irregular surface

long stalk

6
Q

what are adenomas?

A

precursors to adenocarcinomas

benign

7
Q

what do polyps look like histopathologically ?

A

dysplastic epithelial lining

8
Q

what are adenomas of the colon?

A

benign tumours
not invasive
do not metastesise
dysplastic

9
Q

what is the adenoma - carcinoma sequence?

A

normal mucosa > adenoma (dysplastic) > adenocarcinoma (invasive)
genetic injury is involved

10
Q

why must al adenomas be removed?

A

as they are premalignant

done endoscopically or surgically

11
Q

why don’t all colorectal adenomas have the same molecular genetic origins?

A

separate pathway for inherited tumours

separate pathway for serrated adenomas

12
Q

what is the primary treatment for a diagnosis of adenocarcinoma in most cases?

A

surgery

colon/rectum is removed and sent to pathology for staging

13
Q

what does a colorectal cancer look like?

A

tightly packed
moderately differentiated
“dirty” necrosis pattern
can invade muscularis mucosa - blueish gands going down like raindrops

14
Q

what is dukes staging?

A

staging of colorectal cancer that predicts prognosis
Dukes A = confined by muscularis propria = good prognosis (90+%)
Dukes B = through muscularis propria = moderate prognosis (70%)
Dukes C = metastatic to lymph nodes = bad prognosis (35%)

15
Q

do tumours in the proximal/distal bowel present differently?

A

yes

16
Q

where are most colorectal carcinomas?

A

75% left sided (rectum, sigmoid, descending)

25% right sided (caecum, ascending)

17
Q

how does left sided colorectal carcinoma present?

A

blood PR
altered bowel habits
obstruction

18
Q

how does right sided colorectal carcinoma present?

A

anaemia

weight loss

19
Q

colorectal carcinomas generally have a gross, varied appearance, true or false?

A

true

polypoid, structuring, ulcerating

20
Q

are most polyps benign or malignant?

A

benign

can go from benign to dysplastic adenoma to adenocarcinoma

21
Q

where are colorectal carcinomas likely to locally invade?

A

mesorectum
peritoneum
other organs

22
Q

where are colorectal carinomas likely to lymphatically spread to?

A

mesenteric nodes

23
Q

where are colorectal carcinomas likely to spread hematogenously?

A

liver

distant sites

24
Q

what are the 2 group of inherited cancer syndromes of the colon?

A
hereditary
- HNPCC (lynch syndrome?)
- <100 polyps
- present in 50s/60s
- non polyposis
familial
- adenomatous
- polyposis (FAP)
- present at 16
- >100 polyps
25
Q

Describe HNPCC

A
late onset
autosomal dominant
defect in DNA mismatch repair
right sided mucinous tumours
crohns like inflammatory response
associated with gastric endometrial carcinoma
26
Q

describe FAP

A
early onset
autosomal dominant
defect in tumour suppression (FAP gene)
Adenocarcinoma throughout colon
No specific inflammatory response
associated with desmoid tumours and thyroid carcinoma

Decks in GI lectures Class (75):