Extent of Disease: Microscopic or Endoscopic Classification?

Several recent articles highlight the divergence between microscopic and endoscopic classification of disease.

  • Verstraete et al. JPGN 2016; 62: 242-5.
  • Asthon et al. JPGN 2016; 62: 246-51.
  • Pashankar et al. JPGN 2016; 62: 314-16.

The first two references describe histology in comparison to endoscopic extent of disease in pediatric Crohn’s and the 3rd reference provides information on the finding of “duodenitis.”

Verstraete et al selected 60 patients  randomly from their cohort for retrospective review.  Two physicians independently reviewed the patients.  In describing extent of disease, the extent of disease (Paris Classification) was discordant in 34 (56.6%) when comparing  macroscopic disease (imaging and endoscopy) to macroscopic/microscopic combined.  In addition, there was high interobserver variability of the physicians when the physicians reviewed just macroscopic findings (κ= 0.53).

Asthton et al examined data from 172 pediatric patients with inflammatory bowel disease.  They found that histologic disease was more extensive than endoscopic findings.  For example, among those with ileal biopsies, 49% had endoscopic findings compared with 71.3% having histologic disease.

Currently, the Paris classification relies on endoscopic findings; however, together these two studies suggest that the microscopic findings need to be considered as well. How often areas with microscopic disease will eventually develop endoscopic lesions is not clear.

Pashankar et al, reviewed pathology reports over a 5-year periods with 2772 children (mean age 10.6 years).  They identified duodenitis in 352 with a prevalence rate of 12.7%. Gastritis was seen in 64% of children with duodenitis. Interestingly, 63% of the cases with histologic duodenitis had normal endoscopic appearance. Reported reasons for duodenitis:

  • Celiac disease 32%
  • Crohn’s disease 13%
  • Ulcerative colitis 3%
  • Helicobacter pylori infection 6%
  • Functional dyspepsia 7%

The remaining children (36%) were considered to have nonspecific duodenitis.  The authors state: “this finding is similar to the high percentage of nonspecific duodenitis (60%) in adults.”

My take: It is difficult to know how important microscopic findings are in many cases.  With inflammatory bowel disease, whether/how to incorporate microscopic findings in classification is unclear.  With regard to the finding of microscopic duodenitis, when a specific etiology has not been identified, this leads to lots of questions:

  • How important is this finding?
  • How should this be treated?
  • How much additional workup and followup is needed?
  • How helpful is your pathologist –is the threshold for abnormality too low histologically?

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Looking Twice for Eosinophilic Esophagitis

Not only do you have to take a lot of esophageal biopsies, now you may need to call your pathologist to make sure you do not miss a case of eosinophilic esophagitis (EoE), especially if there are mildly increased eosinophils.  At least, that’s the message I inferred from a recent study (Rothenberg ME, et al. JPGN 2015; 61: 65-8).

In this study, the researchers identified 477 biopsies from 429 patients with EoE; 316 were from “PPI confirmed patients.”

Key finding: Of the 477 biopsies, 106 had a peak count of between 1 and 14 eos/hpf cited in the pathology report.  However, 23/106 (22% with 1-14 eos/hpf) had ≥15 esos/hpf after a second review.

Overall, 5% of the 477 biopsies were mischaracterized as not meeting the threshold of ≥15 esos/hpf prior to review.  Given this frequency at a major medical center and frequent referral center for EoE, my suspicion is that the yield of a 2nd look would be at least as high in most other centers.

Take-home point: Look twice for EoE if eosinophil count is between 1/hpf and 14/hpf. Maybe some new diagnoses are being missed and maybe some of your EoE patients in histologic remission really aren’t.

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Grand Tetons from Jenny Lake

Grand Tetons from Jenny Lake