Gastro Flashcards
Commonest cause of oesophagi’s
GORD
Intestinal metaplasia of squamous epithelium leading to replacement with columnar epithelium
Barrett’s oesophagus
Seen in 10% of those with symptomatic GORD
Barrett’s oesophagus
This cancer is associated with Barrett’s oesophagus and is usually seen in distal 1/3
Oesophageal adenocarcinoma
Risk factors include: achalasia, Plummer vinson syndrome, nutritional deficiencies, nitrosamines
Oesophageal squamous cell carcinoma
Where in the oesophagus is squamous cell carcinoma most commonly found?
Middle 1/3
Progressive dysphagia, odynophagia, anorexia, severe weight loss, rapid growth and early spread (LNs, liver and proximal structures)
Oesophageal squamous cell carcinoma
Treatment for oesophageal varies
Emergency endoscopy - sclerotherapy/banding
Neutrophilic infiltrate in submucosa of stomach
Acute gastritis
Risk factors include: aspirin, NSAIDs, corrosives, H. pylori.
Usually transient. May be asymptomatic or show variable epigastric pain, nausea and vomiting
Lymphocytic/plasma cells present in lamina propria
Chronic gastritis
Symptoms generally less severe but more persistent than those of acute gastritis
Causes of chronic gastritis
H. pylori, pernicious anaemia, ETOH, smoking.
Caused by chronic antigen stimulation due to presence of H. pylori
Gastric lymphoma.
Rx: treat H. pylori using triple therapy:
- PPI + carithromycin + amoxicillin or metronidazole
Breach through muscularis mucosa into submucosa of stomach
Gastric ulcer
Type of ulcer exacerbated by food intake
Gastric ulcer
Occurs mainly in elderly
Biopsy shows punched out lesion with rolled margins
Complications: IDA, perforation (erect CXR), malignancy
Bronchoconstricution + flushing + diarrhoea
Carcinoid syndrome
Group of tumours arising from enterochromaffin cells produce 5-HT (serotonin). They are commonly found in the bowel. May also be found in lung, ovaries and testes.
Investigations: 24 hour 5-HIAA (5-HT metabolite)
Rx: Octreotide (somatostatin analogue)
Life-threatening vasodilation, hypotension, tachycardia, bronchoconstriction, hypoglycaemia
Carcinoid crisis
Benign dysplastic lesions that are precursors to most adenocarcinomas
Adenomas
Mostly asymptomatic so need regular surveillance if over 3.4cm as 45% undergo malignant change
Adenomas
Large size is a risk factor for malignancy
Villous adenoma
Rare adenoma that give hypoproteinaemic hypokalaemia due to leak of large amounts of protein and potassium
Mutations involved in progression to adenocarcinoma
APC (1 mutation = at risk, 2 mutations = adenoma)
Further mutations in p53, and activation of KRAS and LOF = adenocarcinoma
Hamartomatous polyp
Benign focal malformation found sporadically in some genetic or acquired syndromes.
Colonic angiodysplasia
Common cause of acute and chronic rectal bleeding + IDA
Juvenile polyps
Type of hamartomatous polyp involving focal malformations of the mucosa and lamina propria. They can lead to bleeding. Usually solitary and found in <5 year olds. Up to 100 found in juvenile polyposis (Autosomal dominant).
Colectomy may be required to stop haemorrhage
Hyperplastic polyp
Seen at 50-60 years. Thought to be caused by shedding of epithelium leading to cell build up
Pseudopolyps
Caused by IBD
Peutz-Jeghers syndrome
Autosomal dominant - LKB1 mutation.
Results in multiple polyps, freckles around mouth, palms and soles, mucocutaneous hyper pigmentation.
Increased risk of intussusception and malignancy – regular surveillance of GI tract, pelvis and gonads
Non-neoplastic polyps (3)
Hamartomatous (juvenile polyposis, angiodysplasia, Peutz-Jeghers)
Hyperplastic polyps
Inflammatory polyps
2nd commonest cause of cancer deaths in Uk
Colorectal carcinoma - 98% adenocarcinoma, 45% in rectum
Name one protective factor against colorectal cancer
NSAIDS
RFs for colorectal cancer
increased fat, decreased fibre in diet, obesity, familial syndromes, chronic IBD
Right sided colorectal cancer
Fe deficiency anaemia + weight loss
Left sided colorectal cancer
Change in bowel habit, cramps LLQ pain
Ivx for colorectal carcinoma
Proctoscopy, sigmoidoscopy, colonoscopy, barium enema, bloods (e.g. FBC) MRI/CT
Tumour marker associated with colorectal cancer
Carcinoembryonic antigen (CEA)
Duke’s staging of colorectal cancer - A
Confined to mucosa
5 year survival >95%
Duke’s staging of colorectal cancer - B1
Extending into muscularis propria
5 year survival 67%
Duke’s staging of colorectal cancer - B2
transmural invasion, no LN involvement
5 year survival 54%
Duke’s staging of colorectal cancer - C1
Extending to muscularis propria + LN metastases
5 year survival 43%
Duke’s staging of colorectal cancer - C2
Transmural invasion + LN involvement
5 year survival 23%
Duke’s staging of colorectal cancer - D
Distant metastases
5 year survival <10%
Surgical management of rectal cancer/low sigmoid cancer
<1-2cm above anal sphincter (lower 1/3 of rectum) - abdominoperineal resection
>1-2cm above anal sphincter - anterior resection
Surgical management of sigmoid cancer
Sigmoid colectomy
Surgical management of colorectal cancer in the descending colon and distal transverse
Left hemicolectomy
Surgical management of colorectal cancer in the caecum, ascending colon and proximal transverse
Right hemicolectomy
Management of colorectal carcinoma
Appropriate surgery + post-surgical radiotherapy to reduce the risk of local recurrence
Chemo in palliative care - 5-FU (fluorouracil)
