Intricacy of Crohn's disease: Incongruity between diagnostic modalities and histopathologic assessment

Crohn's disease (CD) is a chronic and recurrent inflammatory condition. Histologic healing is associated with better outcomes in CD, while less is known regarding the assessment of histological condition. Recently, a study has examined the discordance between endoscopic and histopathologic assessment in ileal CD, revealing a poor correlation between endoscopic and histologic evaluations in assessing mucosal inflammation and disease activity. However, the involvement of CD can span the entire gastrointestinal tract, as well as numerous clinical manifestations and extraintestinal complications, and the patchy nature of transmural inflammation is a well-established characteristic of this disease. The diagnosis of CD relies on a comprehensive evaluation that includes clinical, biochemical, stool, endoscopic, cross-sectional imaging, and histological investigations due to the incomplete understanding of its etiology and pathogenesis. Upon diagnosis, complimentary investigations should focus on markers of disease activity. Since transmural inflammation can only be assessed in resections, therefore, we primarily focused on the evaluation value of clinical aspects, histological scoring systems, particular in vivo imaging evaluation such as computed tomography enterography, magnetic resonance elastography, scintigraphy, sonographically measurement, endoscopic ultrasonography, and advanced endoscopic imaging techniques.