GI Malignancies and Investigation of the GI Tract Flashcards
What are the common GI malignancies?
Cancers of the;
- Oesophagus
- Stomach
- Large intestine
- Pancreas
- Liver
What is the geographical epidemiology of oesophageal carcinoma?
Wide geographical variation, with incidence low in USA, and high around Caspian sea and parts of China
What % of malignancies in the UK does oesophageal carcinoma constitute?
2%
Is oesophageal carcinoma more prevalent in males or females?
Males
What are the clinical features of oesophageal carcinoma?
- Dysphagia
- Weight loss
What happens to the clinical features as an oesophageal carcinoma grows?
It occludes the lumen and causes the progessive worsening of the dysphagia
What investigations are conducted when an oesophageal carcinoma is suspected?
- Endoscopy
- Biopsy
- Barium
What is the most common type of oesophageal carcinoma?
Squamous cell carcinoma
Where does squamous cell carcinoma of the oesophagus occur?
May occur at any level
What is an uncommon type of oesophageal carcinoma?
Adenocarcinoma
Where does adenocarcinoma of the oesphagus occur?
Lower third
What is adenocarcinoma of the oesophagus associated with?
Barrett’s oesophagus
At what stage is oesophageal carcinoma at presentation?
Advanced in most cases
How does oesophageal carcinoma spread?
Direct spread through the oesophageal wall
What % of oesophageal carcinomas are resectable?
40%
What is the prognosis of oesophageal carcinoma?
5% five year survival
What is the second most common GI malignancy?
Gastric cancer
How many new cases of gastric cancer are there in England and Wales each year?
11,000
How common is gastric cancer?
Common
What % of cancer deaths worldwide are accounted for by gastric cancer?
15%
Is gastric cancer more common in men or women?
Men
What is the geographical epidemiology of gastric cancer?
Geographical variation, common in Japan, Columbia, and Finland
What is gastric cancer associated with?
Gastritis
What blood group is gastric cancer commoner in?
A
What is the problem with diagnosing gastric cancer?
Symptoms are often vague
What are the clinical features of gastric cancer?
- Epigastric pain
- Vomiting
- Weight loss
What investigations are used in the diagnosis of gastric cancer?
- Endoscopy
- Biopsy
- Barium
What are the macroscopic features of gastric cancer?
- Fungating
- Ulcerating
- Infiltrative
What kind of gastric cancer shows infiltration macroscopically?
Linitis plastica
What are the intestinal microscopic features of gastric cancer?
Variable degree of gland formation
What are the diffuse microscopic features of gastric cancer?
Single cells and small groups, signet ring cells
How far has early gastric cancer spread?
Confined to mucosa and sub-mucosa
What is the prognosis of early gastric cancer?
Good
How far has advanced gastric cancer spread?
Further spread
Where is advanced gastric cancer common?
UK
What is the 5 year survival rate for advanced gastric cancer?
~10%
How does gastric cancer spread?
- Direct
- Lymph nodes
- Liver
- Trans-coelomic
Where does gastric cancer spread directly?
Through the gastric wall into duodenum, transverse colon, and pancreas
Where does gastric cancer spread trans-coelomically?
- Peritoneum
- Ovaries
Describe the development of advanced gastric cancer from normal gastric mucosa
- Normal gastric mucosa
- H. Pylori infection
- Acute gastritis
- Chronic active gastritis
- Atrophic gastritis
- Intestinal metaplasia
- Dysplasia
- Advanced gastric cancer
What is cancer generally associated with?
Chronic inflammation
Where is gastric cancer common?
Countries with high H. Pylori prevalence
Give an example of a country where gastric cancer is common due to high H. Pylori prevalence
Columbia
What supports the association between H. Pylori and gastric cancer?
Serological and epidemiological evidence
What is the most common GI lymphoma?
Gastric lymphoma
What does gastric lymphoma start as?
A low-grade lesion
What is gastric lymphoma strongly associated with?
H. Pylori
What may eradication of H. Pylori lead to in gastric lymphoma?
Regression of tumour
How does the prognosis of gastric lymphoma differ from that of gastric cancer?
It is much better for gastric lymphoma
How common are gastrointestinal stromal tumours?
Uncommon
What are gastrointestinal stromal tumours derived from?
Interstitial cells of Cajal
What is the causative mutation in gastrointestinal stromal tumours?
C-kit (CD117)
What is the result of the CD117 mutation in gastrointestinal stomal tumours?
It makes it vulnerable to targeted treatment
What behaviour do gastrointestinal stromal tumours display?
Unpredictable;
- Pleomorphism
- Mitoses
- Necrosis
What are the types of tumours of the large intestine?
- Adenomas
- Adenocarcinomas
- Polyps
- Anal carcinoma
What are the types of large intestine adenomas?
- Dysplasia
- Familial Adenomatous Polyposis (FAP)
- Gardner’s Syndrome
What is large intestinal dysplasia?
Benign, neoplastic lesions in the large bowel
What are the macroscopic features of large intestinal dysplasia?
Sessile or pendunculated
What are the microscopic features of large intestinal dysplasia?
Variable degree of dysplasia
What is the clinical relevance of large intestinal dysplasia?
Malignant potential
What happens to incidence of large intestinal dysplasia in western populations?
It increases with age
What kind of syndromes are large intestinal dysplasia?
Genetic
What is the inheritance pattern of familial adenomatous polyposis (FAP)?
Autosomal dominant condition
Where is the FAP mutation?
Chromosome 5
What happens in a patient with FAP by the time they are 20?
There are 1000’s of adenomas in the large intestine, giving a high risk of cancer
What is Gardner’s syndrome?
A similar condition to FAP, with bone and soft tissue tumours
What is the most common GI malignancy?
Colorectal cancer
How many new cases of colorectal cancer are reported each year in England and Wales?
~25,000
What are the macroscopic features of colorectal cancer?
60-70% cases are rectosigmoid fungating/stenotic
What are the microscopic changes seen in colorectal cancer?
- Mucinous
- Signet ring cell type
How do the microscopic changes differ between different colorectal adenocarcinomas?
They are moderately different
How does colorectal cancer spread?
- Direct through bowel wall to adjacent organs (e.g. bladder)
- Via lymphatics to mesenteric lymph nodes
- Via portal venous system to liver
What staging systems are used for colorectal cancer?
- Dukes
- TMN
What are the stages in Duke’s staging?
- A - Confined to bowel wall
- B - Through wall, but lymph nodes clear
- C - Lymph node involvement
- C1 - Highest node clear
- C2 - Highest node involved
What are the mutations found in colorectal cancer?
- Chromosome 5 (in FAP related colorectal cancer)
- Ras mutations
- p53 loss/inactivation
At what age does incidence of colorectal cancer peak?
60-70
What is the geographical epidemiology of colorectal cancer?
- High in UK and USA
- Low in Japan
What conditions increase the incidence of colorectal cancer?
- Polyposis syndromes
- UC and Crohns
What is the aetiology of colorectal cancer?
- Low residue diet
- Slow transit time
- High fat intake
- Genetic predisposition
What is the outcome of colorectal cancer?
Survival time reduces with increasing Duke’s staging
Where does colorectal cancer frequently metastasise to in its advanced stages?
Liver
Other than adenomas, what are the types of large intestine tumours?
- Carcinoid tumour
- Lymphoma
- Smooth muscle/stromal tumours
What kind of tumours are carcinoid tumours of the large intestine?
Neuro-endocrine tumours
What kind of behaviour do large intestinal carcinoid tumours display?
Unpredictable
How common are large intestinal carcinoid tumours?
Rare
Where do lymphomas of the large intestines originate from?
May be primary, or spread from elsewhere
How common are lymphomas of the large intestine?
Rare
How common are large intestinal smooth muscle/stromal tumours?
Rare
What behaviour do large intestinal smooth muscle/stromal tumours display?
Unpredictable
What proportion of pancreas carcinomas are found in the head?
2/3
What is the morphology of pancreatic carcinomas?
Firm pale mass with a necrotic centre
Where may pancreatic carcinomas infiltrate?
Adjacent structures, e.g. the spleen
What is the most common carcinoma of the pancreas?
Ductal adenocarcinomas
What % of pancreatic carcinomas are ductal adenocarcinomas?
80%
How do pancreatic carcinomas appear histologically?
Well formed glands
What do some pancreatic acinar tumours have histologically?
Zymogen granules
What is the prognosis for pancreatic carcinomas?
Poor
What hapens in carcinoma of the Ampulla of Vater?
The bile duct is blocked with only a small tumour
What does carcinoma of the Ampulla of Vater lead to?
Jaundice
What is the prognosis for carcinoma of the Ampulla of Vater?
Good, because blockage leads to early presentation when the tumour is still treatable
How common are islet cell tumours?
Rare
What are the types of islet cell tumours?
- Insulinoma
- Glycagonoma
- Vasoactive Intestinal Peptideoma (VIPoma)
- Gastrinoma
What does an insulinoma lead to?
Hypoglycaemia
What does glycagonoma lead to?
Characteristic skin rash
What does vasoactive intestinal peptideoma lead to?
Werner Morrison syndrome
What does gastrinoma lead to?
Zollinger-Ellison syndrome
Give 3 benign tumours of the liver
- Hepatic adenoma
- Bile duct adenoma/hamartoma
- Haemangioma
How common are benign tumours of the liver?
Fairly rare
Give 3 malignant tumours of the liver
- Hepatocellular carcinoma
- Cholangiocarcinoma
- Hepatoblastoma
How many new cases of colorectal cancer are there in England and Wales per year?
25,000
How many new cases of stomach cancer are there in England and Wales per year?
11,000
How many new cases of pancreatic cancer are there in England and Wales per year?
5,500
What investigations are used to investigate the abdomen?
- Plain x-rays
- Contrast studies
- Ultrasound
- Cross-setional imaging
- Angiography
What type of x-rays are used to investigate the abdomen?
- Abdominal x-ray (AXR)
- Erect chest x-ray (CXR)
What kind of contrast studies are used to investigate the abdomen?
- Barium swallow
- Barium enema
- Barium meal/follow through
- Water soluble contrast studies
What kind of cross-sectional imaging techniques are used to investigate the abdomen?
- Computed tomography (CT)
- Magnetic resonance imaging (MRI)
How big is the dose of radiation given by the techniques used to investigate the abdomen?
Varies considerably
Which techniques for investigation of the abdomen don’t use any radiation?
- Ultrasound
- MRI
Which technique used to investigate the abdomen can deliver a high dose of radiation?
CT scan
How does the radiation dosage given during a CT scan differ from that of an abdominal x-ray?
Can be up to 15x the dose
What are the potential risks of radiation?
- Carcinogenesis
- Genetic
- Developmental risk to foetus
What are contrast studies used to define?
Hollow viscera
What contrast is used in studies?
- Barium
- Water soluble contrast (typically containing iodine)
What are the common types of GI contast studies?
- Swallow
- Meal
- Follow through
- Enema
What is a barium enema?
A barium study where the contrast medium is inserted rectally
What does a barium enema enable?
The colon to be visualised
What does ultrasound utilise to generate images?
Sound waves
What frequency sound waves are used in ultrasound?
Usually 2-18MHz
What are the advantages of ultrasound?
- Cheap compared to CT and MRI
- Portable
What is the disadvantage of ultrasound?
It is highly user dependant
What can an abdominal ultrasound be used to do?
- Determine if the patient has gallstones, or if the common bile duct is dilated
- Can view liver and portal vein, even the appendix
What is the dilation of the common bile duct an indicator of?
That there is an impacted gallstone in the duct
What is the problem with abdominal ultrasounds with the aim to view the liver and portal vein?
The scans are often difficult to interpret, and the usefulness of a scan is often down to who is doing and interpreting the scan
What technique is used to visualise the blood supply to the GI tract?
GI angiography
When is being able to visualise the blood supply to the GI tract very useful?
For bleeding and ishchaemia
How is GI angiography conducted?
By injecting a radio-opaque contrast agent intravenously, and then using various modalities to capture the images
What is shown in this GI angiogram?

The aorta, with the coelic trunk, and superior mesenteric arteries and its branches. The inferior mesenteric artery and it’s branches are harder to see
What structures are visable in an abdominal x-ray?
- Stomach
- Small and large bowel
- Soft tissues
- Liver
- Spleen
- Kidneys
- Psoas muscles
- Bladder
- Lung bases
- Bones
When is a part of a hollow tube visible on an x-ray?
If it is filled with gas
Why are parts of a hollow tube filled with gas visible on an x-ray?
Low density gas acts as contrast
When are lumens not visible on abdominal x-rays?
When they are fully fluid filled
When is the ability to visualise gas filled areas on an abdominal x-ray useful?
Can be used to visualise the stomach (if gas filled), but more commonly used to visualise the small bowel
What are the common reasons for requesting a plain abdominal radiograph?
- Acute abdominal pain
- Small or large bowel obstruction
- Acute exacerbation of IBD
- Renal colic
What abnormalities can be shown on an abdominal x-ray?
- Small bowel obstruction
- Large bowel obstruction
- Volvulus
- Chronic pancreatitis
- Aneurysms with calcification
- Nodes
- Bones
- Artifacts
- Foreign bodies
- Kidney stones
What position does the small bowel usually occupy on the abdominal x-ray?
Central position
What can the small bowel display on an x-ray?
‘Circular folds’, or valvulae conniventes
How do valvulae conniventes appear on x-rays?
As lines that appear to cross the whole of the bowel lumen

What is this x-ray image showing?

The large bowel
What position does the large bowel usually occupy on an x-ray?
A more peripheral position
What is it often possible to see on an x-ray of the larg bowel?
- Haustra
- Faeces
How do haustra appear on an abdominal x-ray?
As incomplete lines going across the lumen
How do faeces appear on an abdominal x-ray of the large bowel?
Like clouds in the lumen
What rule do small and large bowel obstructions follow?
3/6/9
What is the 3/6/9 rule?
- A small bowel is said to be dilated when it is greater than 3cm diameter
- The large bowel is said to be dilated when its greater than 6cm diameter
- The caecum (when the ileoceacal valve is working) is said to be dialted when it is greater than 9cm diameter
What is it important to check when applying the 3/6/9 rule?
That the x-ray is shown to scale
What is this image showing?

A small bowel obstruction
How does a small bowel obstruction usually present?
- Vomiting (early)
- Mild distention
- Absolute constipation (late feature)
- Colicky pain that presents every 2-3 minutes
What is meant by absoloute constipation?
Not passing anything per rectum, even flatus
Why do you vomit early, and experience constipation late, with a small bowel obstruction?
Because the obstruction is nearer the mouth than a large bowel obstruction
What can cause a small bowel obstruction?
- Adhesions
- Hernias
- Tumours
- Inflammation
What kind of hernias can cause a small bowel obstruction?
- Inguinal
- Femoral
- Incisional
What is this image showing?

A large bowel obstruction
How does a large bowel obstruction appear on an abdominal x-ray?
- More at the periphery of the x-ray
- Lines going across the lumen (haustra) are incomplete
How does a large bowel obstruction present?
- Abdominal pain
- Distention
- Constipation (early feature)
- Colicky pain
- Vomiting (late feature)
How does the colicky pain present with a large bowel obstruction differ from that with a small bowel obstruction?
It is not as frequent, being experienced every 10-15 minutes
What is a feature of vomiting in large bowel obstructions?
Can be faeculant
What are the causes of a large bowel obstruction?
- Colorectal carcinoma
- Diverticular stricture
- Hernia
- Volvulus
- Psuedo-obstruction
What is a volvulus?
When a viscera twists around itself, or more commonly when it twists around its mesentery
What is the most common volvulus?
Sigmoid volvulus
What is a more rare type of volvulus?
Caecal volvulus
What is the consequence of twisting in a volvulus?
The enclosed loop of bowel dilates, and is at risk of perforating or cutting of its blood supply (which runs in the mesentery)
What is this arrow showing?

Chronic pancreatitis
When can an erect chest x-ray be useful?
In diagnosing a perforated bowel
What can cause a perforated bowel?
- Peptic ulcer
- Diverticular disease
- Tumour
- Obstruction
- Trauma
- Iatrogenic
Why does the CXR need to be erect when trying to diagnose a perforated bowel
Because you are looking for the diaphragm to be elevated away from any other viscera (the liver on the by the presence of air/gas in the peritoneal cavity. The air/gas will rise to the top of the cavity and so the patient needs to be sat up for 10 minutes prior to the x-ray to ensure this happens
Why is a raised diaphragm indicative of a perforated bowel?
The peritoneal cavity normally only contains a small amount of fluid, so the presence of air/gas is abnormal and could be the result of a perforated bowel
What does an x-ray of a raised diaphragm look like?

What does an abdominal CT use?
- High dose radiation
- IV or oral/rectal contrast
How does the resolution of an abdominal CT differ from that of a MRI?
- Good spatial resolution
- Poor contrast resolution
Draw a diagram illustrating the planes of view that can be acheived by an abdominal CT

Label this transverse abdominal CT

- A - Liver
- B - Stomach
- C - Oesophagus
- D - Spleen
Label this coronal abdominal CT

- A - Right crus
- B - Oesophagus
- C - Stomach (fundus)
- Aorta
Label this sagittal abdominal CT

- A - Right crus of diaphragm
- B - Celiac artery
- C - Superior mesenteric artery
- D - Oesophagus
- E - Aorta
Does MRI imaging use radiation?
No
What is the advantage of MRI imaging?
Good spatial and contrast resolution
What is the disadvantage of MRI imaging?
Time consuming
What is a magnetic resonance cholangio-pancreatogram (MRCP)?
A MRI scan that can visualise the gallbladder and bilary tree
Label this diagram

- A - Gall bladder
- B - Stone in gall bladder
- C - Stone in bile duct
- D - Bile duct