Significance of granuloma and granulomatous lymphangitis in the differential diagnosis of Crohn's disease

Detection Rates of Non-Cavitary Epithelioid Cell Granuloma by Gastrointestinal Biopsy in Patients with Treatment-Naïve Crohn's Disease

Introduction

Detecting non-cavitary epithelioid cell granuloma by gastrointestinal biopsy is important in the initial diagnosis of Crohn's disease (CD). In the present study, we aimed to determine the rate of granuloma detection by gastrointestinal biopsy according to the number of biopsies performed.

Methods

The present study included patients newly diagnosed with CD at our hospital between April 2017 and March 2023. During endoscopic examinations, biopsy specimens were taken from affected lesions. Initially, one section per biopsy was examined to detect granuloma. In cases where no granulomas were detected, step sections were additionally prepared and examined. The rate of granuloma detection by gastrointestinal biopsy was retrospectively examined.

Results

A total of 30 patients with a new diagnosis of CD were included in this study. In total, 284 gastrointestinal biopsies were performed in 29 cases. The rate of granuloma detection by gastrointestinal biopsy per case was 58.6% (17 out of 29 cases). The rate of granuloma detection by gastrointestinal biopsy per biopsy was 6.0% (17 out of 284 biopsies) on initial histological examination and 11.6% (33 out of 284 biopsies) following examination of step sections. The rate of granuloma detection was significantly improved by performing histological examination of step sections compared with initial examinations (p < 0.05).

Conclusion

The rate of granuloma detection per biopsy was 11.6%, even after histological examination of step sections. These results indicate that performing multiple intestinal biopsies and assessing for the presence of granuloma using multiple section examinations are required in the initial diagnosis of CD.

Development and validation of a new algorithm model for differential diagnosis between Crohn's disease and intestinal tuberculosis: a combination of laboratory, imaging and endoscopic characteristics

Background

Sometimes in clinical practice, it is a great challenge to distinguish Crohn's disease (CD) and intestinal tuberculosis (ITB), we conducted this study to identify simple and useful algorithm for distinguishing them.

Methods

We retrospectively reviewed the medical history of the patients who were diagnosed as ITB or CD. We firstly identified ITB patients, and then the patients diagnosed with CD were matched by age, sex, and admission time in a 1:1 ratio. Patients who admitted between May 1, 2013 and April 30, 2019 were regarded as training cohort, and patients admitted between May 1, 2019 and May 1, 2020 were regarded as validation cohort. We used multivariate analysis to identify the potential variables, and then we used R package rpart to build the classification and regression tree (CART), and validated the newly developed model.

Results

In total, the training cohort included 84 ITB and 84 CD patients, the validation cohort included 22 ITB and 22 CD patients. Multivariate analysis showed that, positive interferon-gamma release assays (IGRAs), ≥ 4 segments involved, longitudinal ulcer, circular ulcer, and aphthous ulcer were confirmed as independent discriminating factors. Using these parameters to build the CART model made an overall accuracy rate was 88.64%, with sensitivity, specificity, NPV, and PPV being 90.91%, 86.36%, 90.48% and 86.96%, respectively.

Conclusion

We developed a simple and novel algorithm model covering laboratory, imaging, and endoscopy parameters with CART to differentiate ITB and CD with good accuracy. Positive IGRAs and circular ulcer were suggestive of ITB, while ≥ 4 segments involved, longitudinal ulcer, and aphthous ulcer were suggestive of CD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01838-x.