GI 10 malignancy Flashcards
What are the common GI malignancies?
Oesophagus Stomach Large intestine Pancreas liver
What % of malignancies in the UK are oesophageal carcinoma?
2%
Male>female
What are the clinical features of oesophageal carcinoma?
Dysphagia - progressively worsening
Weight loss
What investigations are done to confirm a diagnosis of GI malignancy?
Endoscopy
Biopsy
Barium
What are the pathological features of oesophageal carcinoma?
Squamous:
Most common
May occur at any level
Adenocarcinoma:
Uncommon
Lower 1/3
Association with Barrett’s oesophagus
What is the presumed pathogenesis of squamous cell oesophageal carcinoma?
Progression through dysplasia
Describe the pathogenesis of adenocarcinoma of the oesophagus.
Arises metaplastic epithelium of Barrett’s oesophagus
Progresses through dysplasia
Controversy over follow-up
What is the prognosis of oesophageal carcinoma?
Advanced disease at presentation in most cases
Direct spread through oesophageal wall
Only 40% resectable
Many patients have a tube passed through tumour to facilitate swallowing
5% five year survival
How common is gastric cancer and what is the prognosis?
15% of cancer deaths worldwide
Poor prognosis
5 year survival <20%
Who is gastric cancer most common in?
Men > women
Japan
Associated with gastritis
Commoner in blood group A
What are the clinical features of gastric cancer?
Symptoms often vague
Epigastric pain
Vomiting
Weight loss
What are the macroscopic features of gastric cancer?
Fungating
Ulcerating
Infiltrative (linitis plastica)
Early
What are the microscopic features of gastric cancer?
Intestinal - variable degree of gland formation
Diffuse - single cell and small groups, signet ring cells
What are the differences in early and advanced gastric cancer?
Early - confined to mucosa/sub-mucosa, described in Japan, good prognosis
Advanced - Further spread, common in UK, <10% five year survival
How does gastric cancer spread?
Direct
Lymph nodes
Trans-coelomic - peritoneum/ovaries
Liver
What bacteria is associated with gastric cancer?
H. pylori - general association of chronic inflammation with cancer
What is the most common GI lymphoma? Give some details.
Gastric lymphoma
Starts as low-grade lesion
Strong association with Hp
Eradication of Hp may lead to regression of tumour
Prognosis much better than gastric cancer
Describe GI stromal tumours.
Uncommon Derived from interstitial cells of Cajal C-kit (CD117) Specific targeted treatment Unpredictable behaviour - pleomorphism, mitoses, necrosis
What are the different types of tumours of the large intestine?
Adenomas
Ademocarcinomas
Polyps
Anal carcinoma
What are the macroscopic and microscopic features of large intestinal adenomas?
Macro - sessile or pedunculated
Micro - variable degree of dysplasia
What is the incidence of large intestinal adenomas?
Increase with age in western population
Genetic syndromes associated
Definite malignant potential
What genetic conditions are associated with large intestinal adenomas?
Familial adenomatous polyposis - autosomal dominant, chromosome 5. Thousands of adenomas by 20ys. High risk of cancer
Gardner’s syndrome - similar to FAP. Bone and soft tissue tumours
How are adenomas and carcinomas similar?
Geographical and anatomical distribution
Synchronous and metachronous lesions
Adenomas with invasion
What are the macroscopic features of colorectal adenocarcinoma?
60-70% rectosigmoid
Fungating (esp right)
Stenotic (esp left)
What are the microscopic features of colorectal adenocarcinoma?
Moderately differentiated
Occasionally mutinous and signet ring cell types present
How does colorectal adenocarcinoma spread?
Direct through bowel wall to adjacent organs e.g. bladder
Via lymphatics to mesenteric lymph nodes
Via portal venous system to liver
How is colorectal adenocarcinoma staged?
Duke’s staging:
A - confined to bowel wall
B - through wall, lymph nodes clear
C - Lymph nodes involved
TNM
What genetic conditions are associated with colorectal adenocarcinoma?
FAP - chromosome 5
RAS mutations
18q (DCC) deletion
17p (p53) loss/inactivation
What is the incidence of colorectal adenocarcinoma?
peak 60-70
High UK/USA, low Japan
Polyposis syndromes
UC (and crohn’s) associated
What is the aetiology of colorectal adenocarcinoma?
Low residue diet
Slow transit time
High fat intake
Genetic predisposition
What are the likely outcomes for colorectal adenocarcinoma?
Survival reduces with increasing Duke’s staging
Liver metastases common in advanced disease
Chemotherapy - palliative
Resection of liver deposits gaining support
Local radiotherapy for incompletely excised lesions
What are some other large intestinal tumours?
Carcinoid tumour - rare neuro-endocrine tumour, difficult to predict behavious
Lymphoma - rare, may be primary or spread from elsewhere
Smooth muscle/stromal tumours - rare and unpredictable
How is pancreatic carcinomaa diagnosed?
Imaging. Usually delayed, early symptoms vague -> weight loss, jaundice, Trousseau’s sign
Describe the morphology of carcinoma of the pancreas
2/3 in head
Firm, pale mass
Cut surface - necrotic, haemorrhagic, cystic
May infiltrate adjacent structures e.g. spleen
What is the histology of carcinoma of the pancreas?
80% ductal adenocarcinomas
Well-formed glands +/- mucin
Some acinar tumours containing zymogen granules
All types have a poor prognosis
Describe the different islet cell tumours
Rare Insulinoma - hypoglycaemia Glucagonoma -> characteristic skin rash VIPoma -> Werner Morrison syndrome Gastrinoma -> Zollinger-Ellison syndrome
What are the different types of benign liver tumours?
Hepatic adenoma
Bile duct adenoma/hamartoma
Haemangioma
What are the different primary malignant liver tumours?
Hepatocellular carcinoma
Cholangiocarcinoma
Hepatoblastoma
etc
What are the options for imaging the GIT?
Plain x-ray Contrast studies Ultrasound Cross-sectional imaging Angiography
What are the risks of using radiation?
Carcinogenesis
Genetic
Development risk of foetus
When would you request an abdominal x-ray?
Acute abdominal pain
Small or large bowel obstruction
acute exacerbation of IBD
Renal colic
What are the features of an AXR?
Bowel pattern
Soft tissue structures
Bones
When is a part of a hollow tube visible in and AXR?
When gas filled - low density gas acts as a contrast
Fully fluid filled not visible
How are abnormal gas patterns viewed?
Small bowel obstruction >3cm Large bowel obstruction >6cm - competent ileocaecal valve (caecum >9cm), incompetent ileocaecal valve May be seen: in the ileum, volvulus toxic megacolon (rule of 3s - 3/6/9)
What is the presentation of a small bowel obstruction?
Vomiting (early)
Distension (mild)
Absolute constipation (late)
Colicky pain
What are the causes of small bowel obstruction?
Adhesion
Hernias
Tumours
Inflammation
What is the presentation of a large bowel obstruction?
Vomiting (late, faeculant)
Distension (significant)
Pain
Absolute constipation
Wat are the causes of large bowel obstruction?
Colorectal carcinoma Diverticular stricture Hernia Volvulus Pseudo-obstruction
What is a volvulus?
Twisting around mesentery
Enclosed bowel loop - dilates - perforation, ischaemia
Sigmoid volvulus common, caecal uncommon
What are the classic signs of sigmoid volvulus on an AXR?
Coffee bean sign towards RUQ, dilation of proximal bowel
What are the classic signs of a caecal volvulus?
‘mobile’ caecum (20%) with mesentery
Can AXR be used to see inflammation and infection?
Yes but not god standard - will see:
Mucosal thickening
Featureless colon
Bowel wall oedema
What is toxic megacolon?
Acute deterioration with UC or colitis
Colon dilatation
Oedema
Pseudopolyps
What are the features of lead pipe colon?
featureless colon
loss of hausfrau
Chronic UC
What other abnormalities can be seen in AXR?
Stones Organs/masses Calcification - pancreatitis, vascular, nodes Bones Artefact Foreign body
What might cause perforation in the GIT?
Peptic ulcer Diverticular Tumour Obstruction Trauma Iatrogenic
What contrast studies are used to define hollow viscera?
Barium
Water soluble
What are the common GI contrast studies?
Swallowing
Meal
Follow through
Enema
What is used for an abdominal CT scan?
High dose radiation
IV or oral/rectal contrast
Good spatial resolution
What does CT stand for?
computerized axial tomography
What does MRI stand for?
Magnetic resonance imaging
What are the pros and cons of MRI?
No radiation
Good spatial and contrast resolution
Time consuming
How does an ultrasound work?
Use of sound waves to generate image - frequency above audible range of human hearing
Cheap, portable but highly dependent on user
