tbl 4 pathology (IBD) Flashcards
[Normal colonic mucosa]
- Made of crypts that extend through the mucosa into the _____________, with surrounding lamina propria – microvilli present (brush border) without enzymes and no villi
o Goblet cells – production of mucus
o Absorptive cells – salt and water secretion, replaced constantly by stem cells originating from the base of the crypts
o Paneth cells – immune role, at the ___________
- Lamina propria – some inflammatory cells can be seen, such as lymphocytes and plasma cells (no neutrophils normally)
muscularis mucosae; base of crypts
Features of active colitis: neutrophils present in colonic mucosa
o Cryptitis – intra-epithelial neutrophils in _______
o Crypt abscess – neutrophils in ________
o Erosions or ulcerations are part of active disease too
crypts; crypt lumen
Features of chronicity: _________ mucosal crypt architectural distortion due to persistent and severe damage of the mucosa, leading to crypt damage and damage of surrounding connective tissue
o New cells are derived from stem cells but there is __________ of crypts
o __________ (shortened crypts and crypt loss/dropout)
o Abnormal branched crypts
o Loss of parallel test tube like alignment of crypts
o _______________ – lymphoplasmacytic infiltrate in between crypts and muscularis mucosae
o _______/pyloric metaplasia
o Cells populating crypts may be abnormal with a reduction of mucin-secreting goblet cells
diffuse;
architectural distortion;
Atrophy;
Basal lymphoplasmacytosis;
Paneth cell
[Crohn’s disease]
- Chronic inflammatory disease that can affect any part of GIT (mouth to anus), most common in _____________________
o 40% of cases involve terminal ileum only, 30% of cases involve ileum andbcolon, and 30% involve the colon only
- Granulomatous inflammations, transmural – extends through the bowel wall
o Discontinuous ___________ areas or skip lesions - Complicated by sinuses, fistula, perforations and strictures
- Gross pathology
o Ulcers – initially __________ that combine to form serpentine ulcers (along long axis of bowel wall)
§ Transverse ulcers can also be formed
§ ____________ – deep knife-like ulcers, can lead to complications such as perforation, fistula if ulcer is transmural
o Mucosa – normal mucosa project as cobblestones in between ulcerated depressed areas
o Thickened wall – transmural oedema, inflammation, __________ fibrosis and _________hypertrophy
o Strictures
o Creeping fat – with extensive disease, mesenteric fat can extend around the serosal surface
terminal ileum, ileocecal valve or cecum;
sharply demarcated
aphthous ulcers;
Fissuring ulcers;
submucosal, muscularis propria
[Crohn Disease: Microscopy ]
- Patchy involvement with normal areas – cobblestone appearance
o Transmural inflammation with ________________
o Activity – indicated by cryptitis and crypt abscess, ulcerations
o Chronicity – indicated by crypt distortion, epithelial metaplasia, later mucosal atrophy
- ________________ – a hall mark of Crohn’s
o Appears in 30 to 60% of cases, can occur in any layer, under normal or diseased states
§ Intestine, mesenteric nodes or even cutaneous nodules
o If present, is helpful in diagnosis – absence does not exclude Crohn’s disease
o Differential diagnosis – ____________________ (rare)
lymphoid aggregates;
Non-caseating granulomas;
pericryptal granulomas due to crypt ruptures
[Complications of Crohn’s disease]
Extraintestinal manifestations of Crohn’s Disease
o Eye – uveitis, episcleritis
o Musculoskeletal – migratory polyarthritis, __________, ____________
o Skin – ________________, erythema multiforme, finger clubbing, ____________
o Liver – _________________
o Renal stones (calcium oxalate), malabsorption (due to enteritis) – can elad to anaemia and osteoporosis
o Systemic amyloidosis (rare)
- Complications of Crohn’s disease
o Strictures and fibrous adhesions leading to intestinal obstruction
o Fistulae and sinuses – between bowel loops (________________), between bowel loop and bladder (__________), vagina (__________) or anterior abdominal wall (enterocutaneous fistulae)
o Local complications
§ Anal fissures
§ Inflammatory masses, abscesses or intraperitoneal collections
§ Adenocarcinoma of bowel – 4 to 20-fold increased risk
§ Fulminant coliti
sacroiliitis; Ankylosing spondylosis
Pyoderma gangrenosum; erythema nodosum
primary sclerosing cholangitis;
enterocolic fistulae, enterovesical fistulae; enterovaginal
fistulae
[Ulcerative colitis]
- Continuous disease of rectum and extending into proximal colon – granular red mucosa to _____________ to flat mucosal atrophy
- Intervening mucosa appears to be ______, forming psuedopolyps
o Mucosal bridges – connecting polyps
- Based on extent of involvement – proctitis, proctosigmoiditis, pancolitis
- Inflamed areas show abrupt demarcation of diseased and normal areas
- No mural thickening and serosa is normal (unlike Crohn’s disease)
Microscopic changes – mucosal disease
- Activity is indicated by cryptitis and crypt abscess, shallow mucosal ulcerations
o Regenerative mucosa in between ulcerations: psuedopolyps
o Chronicity is indicated by __________, epithelial metaplasia, later __________________
§ Metaplasia – crypt lining cells appear as a different colour than normal
o Granulomas – not seen (compared to Crohn’s disease)
- Although inflammations in ulcerative colitis is typically continuous, exceptions occur where it appears discontinuous – raising possibilities of Crohn’s disease
o ___________ – cecum shows inflammation despite adjacent uninvolved colon
o Appendiceal ulcerative colitis – may be discontinuous with colonic disease
o Post treatment/long standing ulcerative colitis – may show uneven distribution between sites, within sites and within biopsies - In these cases, clinical and endoscopic correlations for correct diagnosis is important
broad based ulcers;
polypoidal;
crypt distortion,
Cecal patch; mucosal atrophy
[Ulcerative Colitis Complications]
- Complications –
o Acute – toxic megacolon
o Chronic – stricture (rare), dysplasia, carcinoma - Fulminant colitis leading to toxic megacolon
o In severe colitis, the colonic lumen is acute, markedly dilated and toxic bacterial products can enter the bloodstream – toxic megacolon
o Very thin bowel wall can lead to possibly multiple perforations and _________
o Severe disease and can complicate any colitis and may need _____________
o Transmural inflammation and fissuring ulcers – does not equate with underlying Crohn’s disease (clinical correlations are important in diagnosis)
peritonitis; emergency colectomy
Colitis associated neoplasia – complication of long term ulcerative colitis or chronic Crohn’s disease
- Risk of dysplasia sharply increases with disease duration 8 to 10 years from onset
o Risk factor of dysplasia and extent of disease – risk factor of dysplasia for ______ > _______ > proctitis only
o Risk of dysplasia increases with more active inflammatory response
o ________________ and IBD – very high risk
§ Such patients are put under surveillance immediately after diagnosis
- Surveillance biopsies to detect dysplasia are conducted for high-risk IBD patients
o Extent – low or high grade or indefinite for dysplasia
o Dysplasia can progress to colitis associated carcinomas
o IBD is usually associated with ____________ and high grade dysplasia may be associated with invasive carcinoma at the same site or another site at the colon
pancolitis; left sided only;
Primary sclerosing cholangitis;
multifocal lesions;
Polypoidal lesions – sporadic adenoma or ulcerative colitis associated dysplasia
- If polypoidal lesions occur in non-diseased area of colon with a normal histology, it is a _____________
- If appearing in the affected region, it is an _______________
o Adenoma-like polypoid lesion
o Flat lesion – irregular and broad based or forms a mass
o DALM – dysplasia associated mass or lesion
- ________________ can help to classify and recognise lesions
regular sporadic tubular adenoma;
ulcerative colitis-associated adenoma;
High definition video endoscopy
Microscopic colitis – 2 conditions both presenting with watery diarrhoea and near normal endoscopy (histology is crucial for diagnosis)
- Lymphocytic colitis – increased IEL and lymphocytes/plasma cells in Lamina propria
o Association with celiac disease
- Collagenous colitis – thickened _______________ and increased IEL and lymphocytes/plasma cells in lamina propria
o Common in women, association with _______ and NSAID
subepithelial collagen band;
celiac disease
Diversion colitis: another type of chronic colitis
- ___________ with a blind distal end of colon
– following surgery in ulcerative colitis, Hirschsprung patients
- Marked lymphoid follicular hyperplasia with or without inflammatory activity
- Loss of fecal nutrients that are needed for mucosal integrity (short chain fatty acids) – mucosal damage
Fecal diversion
Diverticular disease
- Blind outpouching (diverticulum) lined by mucosa communicating with the lumen
o True diverticulum (involves all layers of bowel wall) or false diverticulum (_________________only)
- Risk factor – low fibre diet (Western)
- Most common in the colon, especially _________ due to an increase in intraluminal pressure e.g. excessive straining in constipated patients
- Outpouching through the muscularis propria into the pericolic fat – commonly via weak points in the bowel wall such as areas where neurovascular bundles transverse the wall
- Complications
o Obstruction by faecal material – can lead to _____________
o Perforation – pericolic abscess or peritonitis
o Fistulas
o Segmental diverticular disease associated colitis
mucosa and submucosa ;
sigmoid region;
diverticulitis (inflammation)
