GI Session 10 Flashcards
What are the clinical features of oesophageal carcinoma?
Progressive worsening dysphasia from dry solids –> liquids and weightloss
What are the pathological features of oesophageal carcinoma?
Squamous cell can occur anywhere in the oesophagus
Adenocarcinoma occurs in the lower 1/3 where Barrett’s is seen
What is the pathogensis of SCC of the oesophagus?
HPV/tannin/vitamin A deficiency/riboflavin deficiency –> dysplasia –> neoplasia
What is the pathogensis of adenocarcinoma of the oesophagus?
Metaplaetic epithelium –> dysplasia –> neoplasia
What is the prognosis for oesophageal carcinoma?
Most pts present with advanced disease where there is direct spread through the oesophageal wall –> 5% 5-year survival rate
Describe the epidemiology of gastric cancer.
Accounts for 15% of cancer deaths worldwide
More common in men
High incidence in Japan, Columbia and Finland
Associated with gastritis and blood group A
What are the clinical features of gastric cancer?
Vague symptoms –> epigastric pain, vomiting and weight loss in advanced disease
What are the macroscopic pathological features of gastric cancer?
Early is confined to submucosa/mucosa
Late appears fungating, ulcerating, infiltrative
What are the microscopic features of gastric cancer?
Intestinal cancers are all adenocarcinomas with variable degrees of gland formation
Diffuse disease –> single cells, small cells, signet ring cells
What is the pathogenesis of gastric lymphoma?
H.pylori –> low grade lesion –> neoplasia of B lymphocytes
What is the pathogenesis of gastric cancer?
H.pylori –> early confined to mucosa/submucosa –> advanced spreads direct/lymph/liver/trans-coelomic to peritoneum +/- ovaries
What is the pathogensis of GI stromal tumours?
Intestinal cells of rajal (gastric pacemaker) become neoplastic –> C-kit serum marker release
What is used to assess the risk of unpredictable GI stromal tumours?
Site and size of lesion
Degree of pleomorphism, mitoses and necrosis
What is the commonest GI lymphoma?
Gastric
What is the prognosis of gastric cancer?
Early gastric = good
Advanced gastric = 10% 5-year survival rate
Lymphoma = good
Stromal = unpredictable
How are gastric cancers treated?
Surgery
Chemotherapy
Herceptin
Imatinib for stromal
Describe the epidemiology of oesophageal carcinoma.
Accounts for 2% of malignancies in the UK
Higher incidence in men
Highest incidence in China
SCC more common but incidence decreasing, opposite for adenocarcinoma
Describe the epidemiology of large intestine adenomas.
Increased incidence with age in western population and increased incidence with genetic syndromes
Describe the epidemiology of large intestine adenocarcinomas.
Peak at 60-70 y.o. In UK
Higher incidence in polyposis syndromes, UC and Crohn’s
Are carcinoid tumour, lymphoma and smooth muscle tumours of the large intestine common?
No, they are rare
What are the clinical features of large intestinal adenocarcinomas?
R side rectosigmoid –> anaemia
L side rectosigmoid –> obstructive symptoms
What are the pathological features of large intestinal adenomas?
Variable degree of dysplasia microscopically and sessile/pedunculated mascroscopically
What are the pathological features of large intestine adenocarcinomas?
60-70% rectosigmoid –> fungating on R, stenotic on L
See microscopically with moderately differentiated adenocarcinoma or occasionally mucinous or signet ring cell type
What provides evidence for the adenoma-carcinoma sequence?
Geographical and anatomical distributions very similar
Synchronous lesions
Metachronous lesions
Adenomas with invasion
What is the aetiology of large intestine adenomas?
FAP
Gardeners syndrome
What is the pathogensis of large intestine adenocarcinoma?
+/- previous Adenoma
Low residue diet/slow transit time/high fat intake/genetics –> neoplasia
How does large intestine adenocarcinoma spread?
Directly
Lymph
Portal venous system
What is FAP?
Autosomal dominant in chromosome 5 –> 1000s of adenomas by 20 y.o.
What is Gardener’s syndrome?
Similar to FAP –> nine and soft tissue tumours
Where are carcinoid tumours usually found in the large intestine?
Appendix but can be anywhere
Why do carcinoid large ins testing tumours have a normal mortality rate despite being hard to predict?
Rarely metastasise
How is the prognosis of large insets tonal adenocarcinoma assessed?
Duke’s staging then TNM
What is commonly seen in advanced large intestine adenocarcinoma?
Liver metastases
What are the Tx options for adenocarcinoma of the large intestine?
Palliative chemotherapy
Resection of liver deposits
Local radiotherapy for rectal cancer
What are the primary malignant tumours of the liver?
Hepatocellular carcinoma
Cholangiocarcinoma
Helatiblastoma
What are the clinical features of carcinoma of the pancreas?
Early symptoms vague –> diagnosis delayed until weight loss, jaundice or Trossaeu’s sign seen
What is Trosseau’s sign?
Trypsin release –> fleeting thrombophlebitis
What can imagine allow in carcinoma of the pancreas?
Radiological diagnosis from small lesions
What are the pathological features of carcinoma of the pancreas?
2/3 in head –> firm pale mass which on cutting appears necrotic/haemorrhagic/cystic
80% ductal with well formed glands +/- mucin
Some acinar tumours contain zymogen granules
What is the aetiology of carcinoma of the pancreas?
Islet cell tumours (rare) Gastrinoma --> Z-E syndrome Insulinoma --> hypoglycaemia Glucagonoma --> definitive skin rash (Vasoactive intestinal peptide) VIPoma -->Werner Morrison syndrome
What is the prognosis for any type of carcinoma of the pancreas?
Poor
What methods can be used to image the GI tract?
Plain X-rays Contrast studies: barium swallow/enema/meal/follow through or water-soluble contrasts US CT for emergency pts MRI Angiography
When should an AXR be requested?
Small/large bowel obstruction
Acute IBD exacerbation
?toxic megacolon
When should an AXR not be requested?
Acute abdominal pain (most causes not visible)
Renal colic
Constipation
What projection are all AXR?
AP
What should be included in an AXR?
Public tubercle
T5
Properitoneal fat stripes
When might properitoneal fat stripes not be visible?
Lost on pathology e.g. appendicitis
What contents should be seen in the bowel due to its transit time?
Stomach (medium t.t.) = fluid and lots of gas Small bowel (fast t.t.) = fluid Large bowel (slow t.t.) = faeces +/- gas
How can the small bowel and colon be distinguished on AXR?
Small bowel is central with valvulae conniventes
Colon is peripheral with haustra
How is the rule of 3s used to assess abnormal gas patterns?
> 3 cm = small bowel obstruction
6 cm = large bowel obstruction with incompetent iliocaecal valve
9cm = large bowel with competent iliocaecal valve
What soft tissues should be identifiable on a normal AXR?
Liver Spleen L+R kidneys Bladder Psoas muscle
What can be used as an approximate measure of 3 cm on radiograph?
Vertebral body height
What causes small bowel obstructions?
Adhesions from surgery
Hernias esp inguinal
Tumours
Inflammation
What are the progressive S/S of small bowel obstruction?
Vomiting –> mild distension –> absolute constipation –> colicky pain
What causes large bowel obstruction?
Colorectal carcinoma Diverticular stricture Hernia Volvulus Pseudo-obstruction
What are the S/S of large bowel obstruction?
Vomiting (faeculant when late)
Significant distension
Pain
Early absolute constipation
What is the pathogenesis of volvulus?
Twisting around mesentery–> enclosed bowel loop –> dilation –> perforation and ischaemia
Why causes volvulus in the caecum?
Lack of mesentery
How does sigmoid volvulus appear on AXR?
Starts in LIF –> coffee bean sign to RUQ –> proximal bowel obstruction
What is the pathogenesis of toxic megacolon?
Acute deterioration of UC –> colonic dilatation –> oedema and pseudopolyps
What is the pathogenesis of lead pipe colon?
UC causes chronic inflammation –> loss of haustra so featureless colon
What is thumbprinting on AXR?
Active inflammation often in UC but also oedematous processes –> oedematous thickened haustra –> thickened wall
What extra-GI abnormalities are visible on AXR?
Renal calculi Chronic pancreatitis Vascular calcification AAA Foreign bodies
What is the pathogensis of pneumoperitoneum?
Peptic ulcer/diverticular/tumour/obstruction/trauma/iatrogenic –> air under diaphragm
What is used to identify pneumoperitoneum?
Erect CXR after sitting for 10-20 mins
CT
What is visible on CT taken at T12?
Loves of liver Curves of stomach Coeliac trunk AA IVC Hepatic veins
What is seen on CT taken at L1?
(Transpyloric plane of Addison) Lobes of liver Pancreatic head Renal hila Spleen Transverse colon
What are the advantages of using CT to image the abdomen?
Gives good spatial resolution
Reformatting can be used to identify mechanisms of injury
Can be used to build virtual colonoscopy instead of barium enema
What are the applications of MRI in imagine the abdomen?
Good spatial and contrast resolution
Moving object cause blurring but this can be used with fluid to examine peristalsis in Crohn’s (absent in active disease)
What is the clinical application of abdominal US?
Cheap and portable but highly user dependent
Gallstones
Dilated CBD
Examine bowel wall layers e.g. In appendix
Combine with endoscopy
