Gastrointestinal Pathology Flashcards
What part of the body is affected by zenker’s diverticulum
Oesophagus
What causes zenker’s diverticulum
- Weakness in muscle wall
- Pseudo-diverticulum
What are the symptoms of zenker’s diverticulum
- Halitosis
- Dysphagia
- Regurgitation
What part of the body does Achalasia happen in
oesophagus
What causes Achalasia
- Failure to relax the lower esophageal spinster (LES)
- Functional obstruction
- Failure of peristaltic mechanism preventing opening of cardiac sphincter
- Reduced number of ganglionic cells in the myenteric plexus
How does achalasia present in young people
Dysphagia
What are the different types of oesphagitis
- Infective oesophagitis
- Drug induced oesophagitis
- Reflux oesophagitis (GORD - gastro-oesophageal reflux disorder)
What can cause infective oesophagitis
Bacteria, virus, fungi, parasites
Drug induced oesophagitis
Aspirin, ibuprofen, doxycycline
What are the symptoms of oesophagitis
- Sliding hiatus hernia
- Delayed gastric emptying
- Dysphagia
- Heart burn
- Regurgitation of stomach contents
- Stricture of Barretts oesophagus can occur as a result
What is Barrett’s oesophagus
Replacement of distal oesophageal squamous epithelium by metaplastic columnar epithelium.
What causes Barrett’s oesophagus
Due to long standing GORD with ulceration and inflammation of squamous epithelia
What are the clinical presentations of Barrett’s oesophagus
- Band of red, velvety mucosa at GEJ
- Microscopically; intestinal-type epi
- Metaplasia can progress to dysplasia
- Increased risk of adenocarcinoma
Where in the oesophagus do adenocarcinomas form and what is associated with it
lower 1/3 and associated with GORD and Barrett’s
Where in the oesophagus do squamous carcinomas form and what is associated with it
upper 2/3 of oesophagus and associated with smoking and alcohol
What part of the body does gastritis occur in
the stomach
What is gastritis
Inflammation/irritation of the stomach linings
What can cause Gastritis
NSAIDs - blocks prostaglandin synthesis
Stress - decreased blood flow to the mucosa, severe burns, trauma and ITU
- Zollinger-ellison syndrome
- H-pylori associated chronic gastritis
Where does peptic ulcer disease most commonly occur
in the duodenum
What is a peptic ulcer
This is a breach of the mucosa extending through the muscularis mucosa into deeper layers
What is peptic ulcer disease associated with
H-Pylori infection
What are the 2 types of gastric cancer
Intestinal and Diffuse carcinomas
Where do intestinal carcinomas form
- Gland forming columnar epithelium
- Polypoid growth
What are diffuse carcinomas also known as and why are they called diffuse carcinomas
Single signet cell ring
Called diffuse carcinomas as their growth diffuses through the intestine
What are krunkenburg tumours
These are tumours that start in the stomach and develop into ovarian cancers as well
What is Celiac disease caused by
T cell mediated inflammatory disorder that causes sensitivity to the gliadin protein component of gluten (diffuse enteritis)
Describe the histology of celiac disease
Damage to the surface epithelium, reverts to normal with gluten withdrawal
How is nutrients absorption affected by celiac disease
it is impaired
What can appendicitis caused by
Obstruction of the appendices lumen by a fecalith, calculus, tumour or worms.
This increases intraluminal pressure, oedema and exudate due to bacterial invasion leads to schema
What is a mucocoele and a pseudomyxoma peritonea
tumours of the appendix that are either benign or slow growing
Where does diverticular disease often form
Distal colon
What is the main symptom of diverticular disease
Chronic constipation - increased intraluminal pressure
What is diverticular disease associated with
low fibre diets - slow transit of food through colon
Describe the histology of diverticular disease
Outpouchings of the colon
What is peritonitis
Infection of the inner lining of the stomach/ perforation of the stomach
Describe the features of ulcerative colitis
Lesions continuous - mucosal Rectum always involved Malignant change Often intensely vascular Terminal ileum involved in <10% Ulcerated mucosa
Describe the features of Crohn’s disease
Skip lesions - transmural Rectum normal in 50% Terminal ileum involved in 30% Discretely ulcerated mucosa Malignant change less common
Name some of the extra-intestinal manifestations in IBD
Eye Disorders - Conjunctivitis and Uveitis
Joint - Polyarthropathies
Liver - Sclerosing cholangitis and cholangiocarcinoma
Erythema nodosum and pyoderma gangernosum
Why are dentist likely to see signs of crohn’s
Around 60% of patients with crohn’s present with oral manifestations and this may also be the first sign of the disease
What are polyps
Tumourous masses that protrude into gut lumen
What does neoplastic mean
this means that this structure is something that can become cancerous
What types of non-neoplastic polyps are there
Hyperplastic
Juvenile
Peutz-Jeghers
Describe juvenile polyps
Usually focal and sporadic
1-3cm rounded
Pedunculated with mystically dilated glands
Found in the rectum
Describe Peutz-Jeghers polyps
Large
Pedunculated and lobulated with barbarising smooth muscle around the glands
What are the different types of neoplastic polyp and describe them
Tubular - small and pedunculated
Villous - large and remain sessile
Tubulovillous
Where are colorectal cancers most commonly found
- Caecum and ascending colon
- Recto-sigmoid colon
What is the clinical presentations of a right colon cancer
iron deficiency and weight loss - late symptoms
What are the clinical presentations of a left colon cancer
dark red blood in stool, increased freq of bowel, abdominal pain
What are the clinical presentations of a cancer in the rectum
deep red blood in stool, tenesmus
Mutations in which genes form colorectal cancers
First mutation happens in the APC gene (tumour suppressor), triggering the formation of non-malignant adenomas called polyps.
This APC mutation is followed by mutations in KRAS, TP53 and finally DCC genes
What different stages of histology happens in the formation of a colorectal carcinoma
Nomral colon
Hyperproliferative epithelium
Adenoma
Carcinoma
