RECENT TRENDS IN COLITIS

Moderator : Dr Kala

Presenter: Dr Shashikala C

Changes in recent years include:

-Wide spread use of full colonoscopy

-greater recognition of the effects of time and treatment

-improved documentation of variations in anatomical

distribution

-better understanding of the mimics of IBD

-Significant progress in clinical management

-modifications of terminology

Value of biopsy assessment

Confirmation of the diagnosis of IBD

Distinction between UC and CD

Exclusion of dysplasia

Exclusion of coexistent conditions or complications

Also…..

Disease activity

Disease extent

Tissue sampling

Taken from

Both endoscopically normal and abnormal mucosa

Samples of - ileum

-atleast four colonic sites

-the rectum

With minimum of two biopsies from each site

Is the mucosa inflammed?

Chronic inflammatory cell infiltrate

Histiocyte/macrophages-

muciphages are normal findings especially in colon

Eosinophils-

normal in lamina propria

sparse intraepithelial eosinophils

Acute inflammatory cells-

A few intraepithelial neutrophils are normal[2-

3/biopsy]

Crypt architecture

Villiform/irregular mucosal surface

Crypt distortion and branching

Crypt atrophy

Basal plasmacytosis

Basal lymphoid aggregates

Cryptitis ,crypt abscess and granulomas

Mucin depletion

Paneth cell metaplasia

Distribution , Extent and Activity

Distribution of chronic inflammatory cells and crypt changes

Between anatomical sites

Between biopsies from the same site

Within biopsies

Terms for distribution within biopsies and within single site:-

For chronic inflammatory infiltrate- diffuse , patchy, focal

For crypt changes and acute inflammation- diffuse , focal

Diffuse chronic inflammation

Patchy chronic inflammation

Terms for distribution between sites

-continuous between sites

-segmental/ discontinuous between sites

Diagnostic value :

Distribution between sites-

continuous favours UC and discontinuous/segmental

favour CD

Distribution within sites /within biopsies

diffuse favours UC and focal/ patchy favours CD

An increased severity from proximal to distal favours UC and

right sided predominance favours CD

Extent of disease

-Determined endoscopically

- Extent in UC helps to predict the risk of dysplasia

- Extent in CD is difficult to determine

- Histological extent does not always correlate with

endoscopic extent

Activity

Histologic activity confirmation requires

cryptitis

crypt abscesses

surface epithelial neutrophils

erosion or

ulceration

IBD VERSUS NON IBD

IBD vs acute infective colitis/ acute self limiting colitis/ non-

IBD colitis

History :

Infective colitis- bloody diarrhea and associated symptoms

lasts for shorter duration

no relapse

secondary to shigella, salmonella,

campylobacter

Features favouring infective colitis over IBD

IBD versus infective colitis: exceptions

▸ Crypt distortion occurs in a minority of infective coli- tides,

particularly in the healing phase or if infection is severe or

prolonged.

▸ A few infective colitis biopsies have basal plasmacytosis or

other evidence of chronic inflammation.

▸ Crypt abnormalities may be absent from IBD biopsies,

especially in early or treated disease.

▸ Some IBD biopsies have little or no basal plasmacytosis/

chronic inflammation, particularly early in the course of

disease or after treatment.

UC Vs CD: Histology

Assignment to a category

Effects of time and treatment

Pediatric UC

Children have higher prevalence of discontinuous disease

rectal sparing and pan colitis

Low prevalence of chronic histological changes

Upper GI involvement more in children

Ileal and upper gastrointestinal biopsies

Ileal biopsies:-

In setting of IBD ileal inflammation strongly favours CD over

UC.

Granulomas[ non cryptolytic] in inflamed ileal biopsies help

discriminate CD from UC

Upper GI biopsies:-

CD> UC

GERD , H pylori to be excluded

In a setting of IBD upper GI granuloma favours CD over UC

- may raise the possibilities of new CD but caution is

advised

MIMICS OF IBD

Diverticular colitis

Usually localised to sigmoid colon

Often older patients

History endoscopy reqiured for diagnosis

Diversion proctocolitis

May resemble UC/CD

History required

Ischaemic colitis

Basal plasma cells are absent

Mild acute inflammation

Hyalinisation of lamina propria and fibrosis are typical

Clinical picture and anatomic distribution helps to make

diagnosis

Microscopic colitis

Collagenous colitis/ lymphocytic colitis

Plasmacytosis, sometimes basal

No crypt changes

Radiation colitis

Crypt atrophy , distorsion and mucin depletion

Hyalinisation, fibrosis, vascular ectasia, absence of basal

plasma cells

Clinical history

GVHD

Acute GVHD cause crypt atrophy, distortion

Chronic inflammation is minimal

Crypt epithelial apoptoses

Chronic GVHD result in crypt atrophy distorsion with or

without fibrosis

History

Mass lesion

Mucosa overlying intramural and subserosal mass may show

features IBD

Infections

LGV/ syphilis- may resemble CD

left sided > right

HIV/risk factors

Tuberculosis and yersinia

- -Caseous necrosis and demonstrable AFB indicate TB

- -langhans gaint cells, lymphoid cuff around granuloma and

granuloma > 4oomicrometer

- Additional to these presence of stellate abscess favours

yersinia

Drugs

NSAID colitis -

IBD like changes- crypt distortion , granulomas

Clues- epithelial cell apoptosis

increased intraepithelial lymphocytes

Mycophenolate mofetil

Can mimic IBD

But most often confused with GVHD than IBD

FOCAL ACTIVE COLITIS

Focal cryptitis/crypt abscess formation in the absence of other

changes

Represents – IBD, infection, ischaemia, drugs,other causes

It is not regarded as diagnoses

ILEOANAL POUCH BIOPSIES

-to assess severity of inflammation

-seek the evidence of IBD, CMV

-To exclude dysplasia

Adaptive changes- colorectal phenotype and villous atrophy

Identification and sub classification of of IBD is difficult.

DYSPLASIA

Clinical considerations

-pancolic dye spraying with targeted biopsies of

macroscopically abnormal areas

Or random biopsies of 2-4 per 100mm interval

Diagnosis

Low grade/ high grade/ indefinite for dysplasia

Features favouring high grade dysplasia over low grade:

Cytological features-

Complete loss of nuclear polarity

Nuclei larger, more hyperchromatic, more stratified round

ovoid rather than pencil shaped

Mitoses is more

Architecturul changes are severe with cribriform areas

DALM vs adenoma

Depends on endoscopic features

Whether they are located inside or outside the area of IBD

Histology does not distinguish reliably between two

diagnoses

Dual reporting of dysplasia is recommended

terminologies

REPORTING SCHEME FOR IBD BIOPSIES (PAID) Approach

and suggested scheme

The acronym ‘PAID’ is a suggested aide memoire for the

layout of the conclusion to an IBD biopsy report.

P- Pattern: of chronic changes: presence, distribution, extent

A - Activity: maximum grade, location

I- Interpretation: probability of IBD and, if relevant, probability

of UC or CD

D- Dysplasia: location, severity

SUMMARY

Remember

The context when dealing with colitis

Coherence when using terminologies

Corroborate histology with endoscopic findings

Communicate the inability of being more specific

Follow the recent guidelines to screen the high risk

individuals

Pathologist should assist the clinician in diagnosis to

implement appropriate treatment

References

Robbins and cotran pathologic basis of disease- 9th edition

Inflammatory bowel disease biopsies: updated British

Society of Gastroenterology reporting guidelines

Feakins RM. J Clin Pathol 2013;0:1–22.

doi:10.1136/jclinpath-2013-201885

Morson and dawsons gastrointestinal pathology

Pictures from journals of AJG

Thank You