Week 10 - GI Malignancies and Imaging

Question 1

Where in the oesophagus can you get adenocarcinomas?

Answer 1

Lower third

Question 2

What type of rare pancreatic cancer would cause a patient to have a low blood sugar?

Answer 2

Insulinoma

Question 3

Cancer arising in what part of the pancreas can result in a patient becoming jaundiced?

Answer 3

Head - blockage of the common bile duct (about 75% of pancreatic cancers arise either from the head or the neck of the pancreas)

Question 4

Where in the colon would a cancer most likely result in a patient presenting with bowel obstruction?

Answer 4

Sigmoid colon

Question 5

Outline the features of right sided tumours in the large intestine.

Answer 5

1. Fungating
2. Exophytic (grow outwards from the bowel wall)
3. Prone to bleeding
4. Content of the bowel is less solid at this stage as the water content is higher proximally - less likely to be blocked

Question 6

Outline the features of left sided tumours in the large intestine.

Answer 6

1. Grow circumferentially around the lumen of the bowel and cause stenosis
2. Contents of the colon at this stage are more solid as water has been reabsorbed making it more likely that obstructive symptoms are seen

Question 7

Outline the main features of familial adenomatous polyposis.

Answer 7

1. Autosomal dominant condition in which the patient will develop large numbers of (100s-1000s) of adenomatous polyps - adenomas
2. Benign tumours that have the potential to become malignant
3. Due to the large numbers that develop in FAP, patients are certain to develop colonic cancer by age 40 and must undergo a colectomy before that occurs

Question 8

What is the most common location for a lymphoma to develop within the GI tract?

Answer 8

Stomach

Question 9

In which histological classification of gastric adenocarcinomas is Signet ring cells found in?

Answer 9

Diffuse type

Question 10

Outline the structural differences between diffuse and intestinal carcinomas.

Answer 10

1. Diffuse carcinomas: usually composed on chains of single cells which invade the wall of the gut without a sharply defined invasive margin
2. Intestinal carcinomas: develop a more glandular structure lined by mucus-secreting cells. They tend to have a better defined margin than diffuse type carcinomas

Question 11

What GI cancer has the highest incidence in the UK? (males and females)

Answer 11

Colorectal

Question 12

Where do the majority of pancreatic cancers originate from?

Answer 12

Ductal cells: around 80% of pancreatic tumours are ductal adenocarcinomas - rare tumours include acinar cell carcinoma and islet cell tumours (also known as pancreatic neuroendocrine tumours)

Question 13

Under what conditions can serum alanine aminotransferase be elevated?

Answer 13

Direct or acute hepatocellular injury: damage to the liver or hepatocytes, for example by:

1. Viral hepatitis
2. Hypoxic/ischaemic injury to the liver

Question 14

Why is a rise in aspartate transaminase not necessarily indicative of liver damage?

Answer 14

Found in other tissues such as cardiac and skeletal muscle, and is therefore not specific to the liver

Question 15

What does an AST: ALT ratio of greater than 2 suggest?

Answer 15

Alcoholic liver disease

Question 16

What does an AST: ALT ratio of lesser than 1 suggest?

Answer 16

A viral cause

Question 17

What enzyme rises significantly in the presence of obstruction to drainage of the biliary system (e.g. stone in the common bile duct)?

Answer 17

Alkaline phosphatase - present in bile canaliculi

Gamma glutamyl transpeptidase can also be raised in cholestatic damage

Question 18

Which serum enzyme is significantly elevated in Paget’s disease?

Answer 18

Alkaline phosphatase which is present in bones

Question 19

Which liver enzyme is markedly raised in chronic alcohol toxicity?

Answer 19

Gamma-glutamyl transpeptidase (gamma GT)

Question 20

What kind of conditions will patients with lower levels of albumin have?

Answer 20

1. Peripheral oedema

2. Ascites