Gi Flashcards
Classification used for GORD
Los Angeles classification
Metaplasia of squamous to columnar epithelium following chronic GORD
Barrett’s oesophagus
Risk factors of oesophageal adenocarcinoma
Male
Caucasian
Barett’s oesophagus
Risk factors for squamous cell carcinoma
Alcohol and smoking Achalasia of cardia Plummer vinson syndrome Nutritional deficiencies Nitrosamines HPV
Ethnicity risk factor for Squamous cell oesophageal carcinoma
Afrocarribean
M>f
What is stomach lined by?
Gastric mucosa
Columnar epithelium
Glands
MHC class of coeliac disease
DQ2
Dq8 HLA
Rash seen in coeliac disease
Dermatitis herpetiforms
Serological tests to do in coeliac disease
Anti endomysial (best spec and sen)
Anti tissue transglutaminase (IgA) Anti gliadin (Poor marker of disease control)
Gold standard ix of coeliac disease
Upper GI endoscopy and duodenal biopsy
What is seen on duodenal biopsy of coeliac disease
Villous atrophy
Crypt hyperplasia
Lymphocyte infiltrate
Cancer associated with coeliac disease
Duodenal T cell lymphoma
10% progress to this
Location of volvulus in elderly
Sigmoid > caecal
Location of volvulus in infants
Small bowel
Common location of bowel is charm is
Water shed areas
Eg splenic flexure (where the superior mesenteric artery transitions into the inferior mesenteric artery)
Rectosigmoid (where the inferior mesenteric artery transitions into the internal iliac artery)
Abx that increase risk of C. difficile
Cipro
Ceph
Tx of C. difficile
Metronidazole
2nd line is vancomycin
Investigation for C. difficile
Stool culture
Cell origin of tumours causing carcinoid syndrome
Enterochromaffin cell origin
What do enterchronaffin cells produce in carcinoid syndrome which causes the symptoms
Serotonin (5HT3)
Investigation of choice for carcinoid syndrome
24 hour urine 5-HIAA (which is a metabolite of serotonin)
Treatment of carcinoid syndrome
Octreotide
This is a somatostatin analogue
What do villous adenomas cause
Hypoproteinasmjc hypokalaemia
Because they leak large amounts of protein and potassium
Risk factors for malignancy in adenomas
Large size (over 3.4cm)
Degree of dysplasia
Increased villous component
Adenoma to carcinoma sequence
Normal colon is at risk after first hit mutation in the 1st APC gene (those born with FAP have this mutation)
Second hit to the remaining APC gene
Progression to carcinoma following activation of KRAS, LOF, mutations of p53
Juvenile polyposis - autosomal dominant and recessive
Autosomal dominant
Mutated gene in Peutz Jeghers syndrome
LKB1
Autosomal dominant
Symptoms and signs of Peutz Jeghers syndrome
Multiple polyps
Mucocutaneous hyperpigmentation
Freckles around mouth, palm and soles
What are those with Peutz Jeghers syndrome at risk of
Intussuception
Malignancy so regular surveillance of GI tract, pelvis, and gonads
Age group hyperplastic polyp seems in
50-60 years
What type of cancer are the majority of colorectal cancers
98% adenocarcinoma
Most colorectal carcinoma’s are located in
Rectum (45%)
What is protective for colorectal carcinoma
NSAIDs
COX2 is overexpressed in 90% of cases
Clinical feature of right sided colorectal cancer
Anaemia (iron deficiency)
Weight loss
Clinical features of left sided colorectal cancer
Weight loss
Change in bowel habit
Crampy LLQ pain
What can be measured after diagnosis of colorectal cancer to monitor disease
Carcinoembryonic antigen (CEA) This is raised But not very specific or sensitive to be used as a screening tool
Staging used for colorectal cancer
Duke’s staging
TNM can also be used
A, B1-2, C1-2, D
Type of surgery carried out for colorectal cancer if tumour is <1-2cm above anal sphincter (lower 1/3 of rectum)
Abdominoperineal resection
Type of surgery carried out to remove colorectal cancer tumour >1-2 cm above anal sphincter
Anterior resection
Operation for sigmoid cancer
Sigmoid colectomy
What treatment given post op for colorectal cancer to decrease local recurrence
Radiotherapy
What chemo drug used to tx colorectal cancer
5-FU
Fluorouracil
Autosomal DOm or recessive - familial adenomatous polyposis
Autosomal dominant
Gene commonly affected in familial adenomatous polyposis
APC gene (70%) - C5q1
A.R. mutation in DNA Mismatch repair genes in 30% cases
Number of polyps required for diagnosis of familial adenomatous polyps
> 100 adenomatous polyps
At birth, what is seen in patients with familial adenomatous polyposis
Hypertrophy of retinal pigment epithelium
What is Gardner’s
Familial syndrome similar to familial adenomatous polyposis but also with extra GI features eg
Dental carries
Osteomas
Hereditary non polyposis colorectal cancer / lynch syndrome - AD or AR
Autosomal dominant
Mutation in DNA mismatch repair genes
Where do carcinomas usually arise in HNPCC
Right colon
There are few polyps but they Rogers to malignancy fast (<50 years)
Cancers associated with HNPCC
Endometrial
Ovarian
Small bowel
Transitional cell and stomach carcinoma
