IBD Pathology Flashcards
Name the layers of the GI tract
Where does UC start and stop?
Starts at rectum
Stops at Ileocaecal valve- but there may be ‘reflux ileitis’
Large intestine (rectum, colon, appendix)
Starts in rectum
Extends proximally for a varying distance (10-20% total)
Continuous, diffuse
Pathology of UC
Mucosal disease
(unless there is ulceration)
Diffuse active chronic inflammation
Cryptitis, crypt abscesses
Regeneration
Crypt architectural distortion
Reduced goblet cells
CAN CAUSE TOXIC MEGACOLON
Manifestations of UC?
Related to disease activity:
Erythema nodosum
Arthritis
Uveitis
Thromboembolism
Pyoderma gangrenosum
Unrelated to disease activity:
Sacro-iliitis
Ankylosing spondylitis
Liver:
Steatosis
Chronic hepatitis
Primary Sclerosing cholangitis
Cirrhosis
Probability of cancer with UC?
20 years 2.5%
30 years 7.6%
40 years 10.8%
Factors aiding Cancer in UC?
extent of disease (little increase in proctitis)
duration of disease
association with primary sclerosing cholangitis
family history of colorectal cancer
age of onset
persistent inflammation
number and severity of relapses
inflammatory polyps or strictures
long term effective treatment & chemo-prevention
Colitis Screening protocol?
Pathology of cancer in UC?
Signs of Crohns?
Any part of GI tract
colon
Ileum
perianal
Discontinuous (Skip lesions)
Aphthoid ulcers
Fissuring ulceration
Cobblestone mucosa
Strictures
Bacterial overgrowth
Obstruction
Fistulae
Enteric / enterocolic
Cutaneous
Vesical
Vaginal
Transmural disease
Focal lymphoid aggregates
Patchy, focal cryptitis, crypt abscesses
Granulomas (<50%)
Relative preservation of crypt architecture
Oedema
Fibrosis
Toxic dilatation of colon unusual
Extraintestinal and liver manifestations as UC
Colorectal cancer risk increased when widespread colonic involvement (as UC)
Causes of Crohns?
‘Western’ disease, increasing incidence
Smoking
Genetics (CARD15 - NOD2 protein)
Immunology
Ischaemia?
Initiated by infection?
Mycobacteria
NOT MMR
Infective Entero-colitis causes?
Mimicking ulcerative colitis
Bacterial colitis
Pseudomembranous colitis
Amoebiasis
Schistosomiasis
Mimicking Crohn’s disease
Tuberculosis
Yersinia infection
Bacterial Colitis (Dysentry) causes?
Salmonella
Campylobacter
Shigella
Enterotoxigenic Escherichia coli (O159)
Pseudomembranous colitis causes?
Clostridium difficile
Antibiotic-associated colitis
Antibiotics disrupt normal bowel flora that inhibit C. diff overgrowth
Cytotoxin-mediated damage
Toxin detectable in stool
Volcano lesions on biopsy
Treated by metronidazole or vancomycin
Signs of Amoeba infection?
Entamoeba histolyticum
Developing countries
Bloody diarrhoea
Amoeboma
Amoebic liver abscess
Schistosomiasis infection information?
S. mansoni, japonicum
Africa, Far East
Chronic colitis
Predisposes to colorectal cancer
Intestinal TB info?
Mycobacterium tuberculosis or M bovis
Terminal ileum & caecum
Closely mimics Crohn’s disease
Granulomas usual and caseating (unlike Crohn’s disease)
May progress to peritoneal tuberculosis
Yersinia infection information?
Yersinia pseudotuberculosis and Y enterocolitica
Meat (pork) and dairy products
Acute self limiting ileo-caecitis with necrotising granulomas
Examples of Colitis?
Diverticular colitis
Ischaemic colitis
Diversion colitis
Deficiency of luminal (bacterial) nutrients
Microscopic colitis
Lymphocytic
Collagenous
Drug-induced colitis
Causes and signs of microscopic colitis?
Causes:
Chronic watery diarrhoea
General health good
Normal endoscopy and radiology
Abnormal histology
Signs:
Seronegative, non-destructive arthritis
Autoimmune disease
Coeliac disease
Drugs
non-steroidal anti-inflammatory drugs
ranitidine, lanzoprazole
