Pathology of Colon Flashcards Preview

Alimentary System > Pathology of Colon > Flashcards

Flashcards in Pathology of Colon Deck (42):
1

What does the portal venous system transmit?

Deoxygenated blood from most of the GI tract and GI organs to the liver

2

Hepatocytes receive oxygenated blood from the

hepatic artery

3

The mixture of oxygenated and deoxygenated blood received by the liver filters through the

sinusoids

4

The portal vein is formed from

the superior mesenteric and splenic veins

5

Where does the portal vein lie in relation to the hepatic artery and bile duct?

Posterior

6

The portal vein penetrates the right border of the

lesser omentum

7

The porto-systemic/porto-caval anastamosis is the

collateral communication between the portal and systemic venous systems

8

What are the types of ano-rectal conditions?

Congenital/acquired
Local/systemic
Benign/malignant
Early/late

9

What are the most common presentations of ano-rectal conditions?

Pain
Haemorrhage
Dysfunction

10

Ano-rectal conditions can be caused by;

Inflammation
Infection
Malignancy
Trauma

11

Give an example of A congenital an-rectal condition

Imperforate anus
Uro-genital fistulae
Hirschprung's Myenteric Plexus Deficiency

12

Give 5 examples of acquired ano-rectal conditions

Haemorrhoids
Fissure
Abscess
Fistula-in-ano
Ulceration
Cancer
Incontinence

13

What is the typical presentation of haemorrhoids?

Itching/irritation/pain around the anus
Painful bowel movements
Bleeding from anus after defaecation

14

What is the typical surgical treatment for haemorrhoids?

Stapled anopexy
Ultrasound guided ligation of haemorrhoids

15

What are the stagings of anal fissures?

Acute or chronic

16

At what point is an anal fissure classed as chronic

If it has been [resent for more than 6 weeks

17

How is an anal fissure treated?

By relaxing internal anal sphincter;
medically - topical nitric oxide, glyceryl trinitrate paste or diltiazem calcium blocker
surgically - internal lateral sphincterotomy

18

What is the treatment for a peri-anal abscess?

Incision and drainage

19

At what locations can a peri-anal abscess occur?

Submucosal
Intersphincteric
Ischiorectal
Perianal

20

What is the typical presentation of fistula-in-ano?

Pain and swelling around the anus and pain during bowel movements

21

How is a superficial fistula-in-ano treated?

Fistulotomy

22

How is a trans-sphincteric fistula-in-ano treated?

Seton suture, fistula plug or permacol paste

23

What are the causes of anal ulceration?

Crohn's disease
Malignancy
Syphilis chancre
Nicorandil

24

What is the treatment for anal squamous cell carcinoma?

Radiotherapy and surgery

25

What is the treatment for rectal adenocarcinoma?

Neo-adjuvant chemo and radiotherapy and laparoscopic resection

26

Give 6 causes of constipation

Lack of fibre in diet
Change in eating habits
Ignoring urge to defaecate
Immobility/lack of exercise
Low fluid intake
Anxiety/depression
Antacids
Antidepressants
Anti-epileptics
Calcium supplements
Opiate painkillers
Diuretics
Iron supplements

27

What do the majority of colorectal cancers arise from?

Pre-existing polyps

28

What fraction of colorectal cancers are colonic and what fraction are rectal?

Two thirds colonic, one third rectal

29

The majority of polyps are

adenomas

30

What are the main histological types of polyps?

Tubular (75%)
Villous (10%)
Tubulovillous (15%)

31

What appearances can polyps have?

Pedunculated
Sessile

32

What is the basic pathogenesis of colorectal cancer from polyps?

Normal epithelium
-> small adenoma (polyp)
-> large adenoma
-> invasive adenocarcinoma

33

What is the typical presentation of colorectal cancer?

Persistent rectal bleeding
Altered bowel opening (particularly diarrhoea)
Iron deficiency anaemia
Palpable rectal or lower right abdominal mass
Acute colon obstruction (if stenosing tumour)
Systemic symptoms

34

What are the sites of colorectal cancers?

Ascending colon
Transverse colon
Descending colon
Rectum
Anus

35

What is the most common histological type of colorectal carcinoma?

Adenocarcinoma

36

What are the risk factors for developing colorectal carcinoma?

Lifestyle factors
Family history
IBD
Genetics

37

What is the typical presentation of right sided colorectal carcinoma?

Anaemia
Vague pain
Weakness
Obstruction

38

What is the typical presentation of left sided colorectal carcinoma?

Bleeding
Altered bowel habit
Obstruction

39

What investigations would be done to diagnose colorectal cancer?

Colonoscopy
Barium enema
CT colongraphy
CT abdomen/pelvis

40

What is the benefit of a colonoscopy?

Any polyps found can be removed and biopsies can be taken

41

What staging investigations would be doe after a diagnosis of colorectal cancer had been reached?

CT chest, abdomen and pelvis
MRI scan for rectal tumours
PET/rectal endoscopic ultrasound in selected cases

42

What are the treatment options for colorectal cancer?

Surgery - endoscopic if caught early enough
Stoma formation may be required
Removal of lymph nodes for histological analysis
Partial hepatectomy
Chemotherapy
Radiotherapy