Pitfalls in the Diagnosis of Inflammatory Bowel Disease

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1 Pitfalls in the Diagnosis of Inflammatory Bowel Disease Robert H Riddell MD Mt Sinai Hospital Toronto Prof of Lab. Medicine and Pathobiology University of Toronto

2 Atypical gross / endoscopic distribution of disease. Ulcerative colitis typically involves the rectum extends proximally for a variable extend often reverts to normal mucosa - abrupt or gradual.

3 Atypical gross / endoscopic distribution of disease. Pitfalls in UC that mimic Crohn s disease Presence of a cecal or periappendiceal patch. Apparent rectal sparing therapy - not always therapeutic enemas. usually evidence of colitis on biopsy (some degree of architectural distortion, an excess of chronic inflammation including deep plasma cells, and neutrophils that are invariably cryptophilic). Rectal sparing aphthoid ulcers in the transition to typical colitic mucosa. Usually severe disease diverticular colitis Preparation Oral Fleets

4 UC with periappendiceal patch UC with cecal patch

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6 Ulcers and sparing at both ends

7 The skip

8 CD mimicking UC Distribution of disease Diffuse disease Rectal disease Apparent normal rectal mucosa histologically Ab initio Longterm reversion to normal

9 gotcha

10 Pitfalls - other diseases Superimposed infection Bacterial Viral CMV Drugs / medications NSAIDs Pediatric disease Chronic eosinophilic infiltrates (kids) Churg-Straus Chronic allergic colitis Atypical CD-like (young +/- severe UGI disease) Diversion Pouchitis

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17 Rectal stump post colectomy Is it Crohn s? Take 2 Rectal Bx Diversion disease / diversion proctitis Classically mucosal lymphoid hyperplasia BUT Can look focal with aphthoid ulcers or diffuse Can have granulomas Can be diffuse with crypt abscesses If resected can have Crohn s like transmural lymphoid hyperplasia Therefore Can mimic CD or UC Therefore DON T ASK!!! Once it is established we can t tell you. Once established it is always Diversion disease

18 Pouchitis + Fistula. Is it CD? Pouchitis Classically is Crohn s-like Can look focal with aphthoid ulcers Can have granulomas If resected can have Crohn s like transmural lymphoid hyperplasia Therefore Can mimic UC or CD Therefore DON T ASK!!! We can t tell you. It is always Pouchitis Possible exception pre-pouch ileitis with skip Can mimic CD and may respond to Remicade Does that make it CD?

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22 Upper GI disease Established in CD Focal chronic active Hp neg gastritis Hp neg erosions Granulomas? Mild superficial chronic gastritis Severe UC - esp children Active duodenitis (bulb)? Chronic Hp neg gastritis Resolves post Rx / Colectomy

23 Crohn s disease - pitfalls Other causes of focal disease: Biopsy of inflammatory polyps Biopsy of granulation tissue at anastomotic lines Inflammatory kick in cecal biopsies (normal) or in UC Overcalling normal terminal ileal lymphoid aggregates as inflamed Fulminant colitis of any cause including UC (aphthoid ulcers, rectal sparing)

24 Why are there problems? The pathologist does not know or understanding the reasons why the biopsies were taken question or reason biopsies taken not stated. (Can t answer a question if there isn t one) Pathologist is unaware of criteria ( NSp inflammation ) CME courses,web,crack a book,ask The endoscopist is unaware of what biopsies are needed to answer the questions that has been specifically asked know the criteria used to make the diagnoses take the appropriate biopsies to answer the Qu The question being asked cannot be answered at all using biopsies know when pathology cannot answer the question

25 You never give me what I need But Honey you never tell me what you want

26 Pitfalls in Bx in IBD Distribution or focality not demonstrated The occasional biopsy All in one container Cecal Bx (MC-like) / cecal patch misinterpreted Identify separately Mucin granulomas (and giant cells) Focality post Rx how much is allowed? Rarely erosions Apparent rectal sparing or proximal limit Demonstrate it Normal biopsies histologically and implications Ab initio Acquired/repair

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29 Abnormal endo Looks like CD. Is it? Have to demonstrate the distribution and focality Erosions / Aphthoid ulcers / Edges of ulcers Usually on background of focal inflammation Crypt sparing <5% CD is really diffuse Rare in UC (highly asymmetric healing)

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37 Pitfalls Mimics of aphthoid ulcers Biopsies from Inflammatory polyps Anastomotic lines Infections with focal ulcers Preparation artefact

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40 Pitfalls in Surveillance Understand its limitations Don t repeat the colonoscopy to confirm the diagnosis Better methods of surveillance Chromoscopy + Magnification endoscopy Autofluorescence Carcinomas arise from any grade of dysplasia Understand the algorithm for adenomas in colitic mucosa v. DALM

41 Pitfalls in Surveillance Length 100 cm Circumference 10cm Area 1000cm 2 1cm needs 1000/3.14 equally spaced biopsies - c.320 biopsies 2cm Area = πr2 = 3.14cm2 33 Bx for 90% of finding dysplasia if present (55 for 95%) (Rubin artificial)

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43 Singh.jpg M52 20y Hx UC 1cm Polyp in Sigmoid

44 Singh.jpg M52 20y Hx UC 1cm Polyp in Sigmoid

45 Singh3.jpg

46 Singh4.jpg

47 The big myth No/min dysplasia Low-grade dysplasia High-grade grade dysplasia Incipient invasion Invasive Ca

48 How it really works No/min dysplasia Low-grade dysplasia High-grade grade dysplasia Incipient invasion Other Non-dysplastic pathways Invasive Ca

49 In colitic mucosa: Is it an adenoma or a DALM? Adenoma (local excision) Dysplasia Associated Lesion or Mass (DALM) (colectomy) more widespread or atypical?ca If it looks like an adenoma (Adenoma-Like Mass Bernstein) Excise endoscpically good stalk if possible to demonstrate complete excision Biopsy around base to ensure complete Routine surveillance run If excised and rest negative can Rx as Ad Beware atypical lesion + any histological dysplasia

50 AdinUC.jpg

51 AdinUC- 2Arch.jpg

52 DALM-1.jpg

53 DALM-2.jpg

54 Other Pitfalls? The pathologist needs to understand the question or reasons the biopsies were taken Pathologist needs to know their stuff (No Non-specific inflammation ) The endoscopist must be aware of what biopsies are needed to answer their questions Needs to know their stuff Know when pathology cannot answer the question or the limitations

55 How about meeting over that hot little scope of yours Mmmmm Yours or mine?