pitfalls in the diagnosis of inflammatory bowel disease · pitfalls in the diagnosis of...
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Pitfalls in the Diagnosis of Inflammatory Bowel Disease
Robert H Riddell MDMt Sinai Hospital TorontoProf of Lab. Medicine and
PathobiologyUniversity of Toronto
Atypical gross / endoscopic distribution of disease.
Ulcerative colitis typically involves the rectumextends proximally for a variable extend often reverts to normal mucosa - abrupt or gradual.
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 sparingaphthoid ulcers in the transition to typical
colitic mucosa. Usually severe diseasediverticular colitis
Preparation – Oral Fleets
UC with periappendiceal patch
UC with cecal patch
Ulcers and sparing at both ends
The skip
CD mimicking UCDistribution of disease
Diffuse diseaseRectal disease
Apparent normal rectal mucosa histologicallyAb initioLongterm reversion to normal
‘gotcha’
Pitfalls - other diseasesSuperimposed infection
BacterialViral CMV
Drugs / medicationsNSAIDs
Pediatric diseaseChronic eosinophilic infiltrates (kids)
Churg-StrausChronic allergic colitis
Atypical CD-like (young +/- severe UGI disease)DiversionPouchitis
Rectal stump post colectomy –Is it Crohn’s? Take 2 Rectal Bx
Diversion disease / diversion proctitisClassically mucosal lymphoid hyperplasia BUTCan look focal with aphthoid ulcers or diffuseCan have granulomas Can be diffuse with crypt abscessesIf resected can have Crohn’s like transmural lymphoid hyperplasia
Therefore Can mimic CD or UCTherefore DON’T ASK!!! Once it is established we can’t tell you.
Once established it is always Diversion disease
Pouchitis + Fistula. Is it CD?Pouchitis
Classically is Crohn’s-likeCan look focal with aphthoid ulcersCan have granulomasIf resected can have Crohn’s like transmural lymphoid hyperplasia
Therefore Can mimic UC or CDTherefore DON’T ASK!!! We can’t tell you.
It is always PouchitisPossible exception – pre-pouch ileitis with skip
Can mimic CD and may respond to RemicadeDoes that make it CD?
Upper GI diseaseEstablished in CD
Focal chronic active Hp neg gastritisHp neg erosionsGranulomas ? Mild superficial chronic gastritis
Severe UC - esp childrenActive duodenitis (bulb)? Chronic Hp neg gastritisResolves post Rx / Colectomy
Crohn’s disease - pitfalls
Other causes of focal disease:Biopsy of inflammatory polypsBiopsy of granulation tissue at anastomotic lines
Inflammatory kick in cecal biopsies (normal) or in UCOvercalling normal terminal ileal lymphoid aggregates as inflamedFulminant colitis of any cause – including UC (aphthoid ulcers, rectal sparing)
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
“You never give me what I need”
“But Honeyyou never tell mewhat you want”
Pitfalls in Bx in IBDDistribution or focality not demonstrated
The occasional biopsyAll in one container
Cecal Bx (MC-like) / cecal patch misinterpretedIdentify separately
Mucin granulomas (and giant cells)Focality post Rx – how much is allowed?
Rarely erosionsApparent rectal sparing or proximal limit
Demonstrate it “Normal” biopsies histologically and implications
Ab initioAcquired/repair
Abnormal endo – Looks like CD. Is it?
Have to demonstrate the distribution and focalityErosions / Aphthoid ulcers / Edges of ulcers
Usually on background of focal inflammationCrypt sparing<5% CD is really diffuseRare in UC (highly asymmetric healing)
PitfallsMimics of aphthoid ulcers
Biopsies from Inflammatory polypsAnastomotic linesInfections with focal ulcersPreparation artefact
Pitfalls in SurveillanceUnderstand its limitationsDon’t repeat the colonoscopy to “confirm the diagnosis”Better methods of surveillance
Chromoscopy + Magnification endoscopyAutofluorescence
Carcinomas arise from any grade of dysplasiaUnderstand the algorithm for adenomas in colitic mucosa v. DALM
Pitfalls in SurveillanceLength 100 cm Circumference 10cm Area 1000cm2
1cm
2cm
needs 1000/3.14 equally spaced biopsies - c.320 biopsies
Area =πr2 = 3.14cm2
33 Bx for 90% of finding dysplasia if present
(55 for 95%) (Rubin 1992 - artificial)
03-16254Singh.jpgM52 20y Hx UC 1cm Polyp in Sigmoid
03-16254Singh.jpgM52 20y Hx UC 1cm Polyp in Sigmoid
03-16254Singh3.jpg
03-16254Singh4.jpg
The big mythThe big myth
No/minNo/min LowLow--gradegrade HighHigh--gradegrade IncipientIncipientdysplasiadysplasia dysplasiadysplasia dysplasiadysplasia invasioninvasion
Invasive Ca
How it really worksHow it really works
No/minNo/min LowLow--gradegrade HighHigh--gradegrade IncipientIncipientdysplasiadysplasia dysplasiadysplasia dysplasiadysplasia invasioninvasion
Invasive Ca
Other“Non-dysplastic”
pathways
In colitic mucosa:Is it an adenoma or a DALM?Adenoma (local excision)Dysplasia Associated Lesion or Mass (DALM) (colectomy) – more widespread or atypical ?CaIf it looks like an adenoma
(Adenoma-Like Mass – Bernstein)Excise endoscpically – good stalk if possible to demonstrate complete excisionBiopsy around base to ensure completeRoutine surveillance runIf excised and rest negative can Rx as AdBeware atypical lesion + any histological dysplasia
03-2184 3-8AdinUC.jpg
03-2184 3-8AdinUC-2Arch.jpg
03-2184 3-5 DALM-1.jpg
03-2184 3-5 DALM-2.jpg
Other Pitfalls?The pathologist needs to understand the question or reasons the biopsies were takenPathologist 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 stuffKnow when pathology cannot answer the question or the limitations
“How about meeting over that hot
little scope of yours”
“MmmmmYours or mine?”