Pathology in the selection of patients for pouch surgery.

Dr Bryan F WarrenConsultant Gastrointestinal Pathologist, Honorary Senior

Lecturer, Fellow of Linacre College, Oxford

M62 Course 2006

Pathology in pouch surgery

• One stage

• Two stage

• Three stage

One stage-Communication and context

What do I tell the pathologist?

Biopsy – severe UC

Crypts rupture downwards to involve superficial submucosaMimic CD

Distribution and context!

Biopsy pathology UC

• Crypt architectural distortion takes 6 weeks

• Diffuse changes-• Architecture, mucin depletion,

chronic inflammation, acute inflammation

• Rectum most severe• Distribution of changes in a

biopsy and in a biopsy series.• Catch-patchiness-post treatment

or at junction of diseased and normal, or in caecal patch.

• IF BIOPSIES ALL IN SAME POT - HARD TO REPORT!!

Early disease-diffuse Chronic inflammationand basal plasma cells

UC after treatment

Crohn’s colitis

Schiller KFR, Cockel R, Hunt RH, Warren BF. 2001An atlas of gastrointestinal endoscopy and related pathology

Crohn’s colitisFocal erosions and Focal inflammation

Perineural chronic inflammationand granuloma.

Aphthous ulcerGranuloma in relation to ruptured crypt-notall CD

Cryptolytic granulomasLee FD, Maguire C, Obeiat W,

Russell RI.Importance of cryptolytic

granulomas in inflammatory bowel disease. J Clin Pathol 1997;50: 148-152

• 14 patients with non specific inflammatory changes and pericryptal granulomas on biopsy

• 10 were found to have Crohn’s disease

Quiescent/ treated UC

May have only architectural distortion, =/-paneth cells,may return to ‘normal’-review original biopsies ? Infection.

Polyp

Flat mucosa`patchy mimics CDRectal sparing

DON’T JUST BIOPSY THE POLYP

Follow up/ post treatment biopsies in IBD

• Is it still IBD/UC/Crohn’s disease

• Has it got better? Was it IBD after all?

• Is it now complicated by infection/PMC?

• Go back to the original pretreatment series!

Crohn’s large bowel biopsy.

• May be normal

• May mimic UC

• Patchiness is most reproducible feature

• Mucosal granulomas – may mislead

Pathology in pouch surgery

• Two stage and three stage

Colectomy!

• Three stage– Colectomy– Rectal stump

Crohn’s disease - fat wrapping

Crohn’s colitis

Transmural inflammation in the form of lymphoid aggregatesThe pathologist cannot see this on a biopsy - help him - context

Crohn’s colitis-terminal ileal disease.

Backwash ileitis in UC or Crohn’s disease? Ileal biopsies maybe difficult.

Biopsies after surgery

• Ileostomy end - non specific changes may misinterpret as Crohn’s disease

• Anastomotic biopsies in Crohn’s

• Diversion– CD may mimic UC– UC may mimic CD

Diversion in UC• Transmural inflammation

• Granulomas

• PMC like change

• Mimics Crohn’s

• It is UC and not a contraindication to pouch surgery.

• Seen as part of the three stage pouch procedure.

• Comforting if this occurs-helps confirm pouch has been made in UC! PUT THE BIOPSIES IN CONTEXT FOR THE PATHOLOGIST!

Diverted Crohn’s colitis

When is it difficult to differentiate CD colitis and UC?

• Fulminant colitis

• After treatment of UC

• When rare variants of UC are not recognised.

Skip lesions in UC

Acceptable ones:

• Appendix –Davison and Dixon

• Caecal patch – D‘Haens

Not contraindications to pouch surgery.

Caecal patch in UC

Courtesy of Dr Axel von Herbay

Tell the pathologist What you sawPlease label biopsy SitesNot all in same pot!

Indeterminate or unable to tell for the wrong reasons?

Referral to an expert!

Pass on/ share the decision making - good but…

Biopsies minus information

Resection - must be easy, histology must give all the answers!

Photo -absent/poor

Macroscopic description - length of colon only

Slides four from unknown sites around the colon

Remains undiagnosable - not true indeterminate

Working Party clinical classificationIndeterminate Colitis:

use and abusecontroversies and consensus

(WCOG)Séverine Vermeire, MD, PhD (Leuven, Belgium)

Robert Riddell, MD, PhD (Toronto, Canada)Bryan Warren, FRCPath(Oxford, UK)

Karel Geboes, MD, PhD (Leuven, Belgium)

Introduction

• Population-based studies from Scandinavia showed that 5-20% of IBD patients affected by colonic involvement only cannot be definitively diagnosed with CD or UC using available diagnostic tools

indeterminate colitis (IC)

• Incidence of IC estimated at 1.6-2.4/100.000

• What are they calling “IC”

Moum Gut 1997, Hildebrand J Pedriatr Gastroenterol Nutr 1991, Stewenius Scand J Gastroenterol 1995

Definition of IC:evolution of diagnostic criteria

1978: introduction of ‘colitis indeterminate’ by Ashley Price

(J Clin Pathol 1978)

• based on surgical specimens

• features of both CD and UC

Wide-spread use of endoscopy and biopsies

• evolution towards diagnosis based on clinical features + endoscopy +Bxclinical features of chronic IBD, without small bowel involvement; endoscopy non-conclusive ;microscopy active-patchy chronic inflammation with crypt distortion (>10%) and absence of diagnostic features for CD or UC

1978 1980 …………………………………………. 2000 2005

• IC = Temporary diagnosis

• Majority of patients prove to have either CD or UC during follow up

• Is IC distinct disease within IBD?

• Data from epidemiological observations in patients with IC (Stewenius et al J Eur J Surg 1996; McIntyre et al Dis Colon Rectum 1995; Atkinson et al Am J Surg 1994; Stewenius et al Dis Colon Rectum 1996; Stewenius et al Int J Colorectal Dis 1995)

– clinical course– Prognosis

CD, UC or IC: does it matter?

worse compared to UC, especially concerning risk for and outcome of

surgery

“Can I do a pouch?”

• Conflicting data (Dayton Mt 2002, Wells AD 1991, Brown CJ 2005))

– patients operated at St Mark’s London (1960-1983), with diagnosis of IC performed well and were unlikely to develop CD

– Toronto: although greater risk for pouchitis in IC (43%) vs UC (21%), no increased risk for pouch failure with excision (10% vs 6%)

Proposed classification for patients with chronic inflammatory colitis

Diagnosis based on surgical specimen

Diagnosis based on endoscopy with biopsies

• chronic IBD with inflammation restricted to colon and no small bowel involvement.

• non-conclusive endoscopy

• microscopy: active patchy chronic inflammation with minimal or moderate architectural distortion and no diagnostic features for CD or UC. No infectious colitis

overlapping features of both CD and UC

indeterminate colitisUpper GI evaluation (G-scope, double

balloon and/or videocapsule) useful

Colonic IBD Type Unclassified (IBDU)

Summary - Pathology in the selection of patients for pouch

surgery.

Biopsies and resections considered in CONTEXT

Awareness of rare variants and effects of treatment

Consistent use of terminology Multidisciplinary team approach