Architectural crypt distortions in ulcerative colitis: Time for reappraisal

Area of Science:

• Gastroenterology
• Histopathology
• Inflammatory Bowel Disease

Background:

• Chronic mucosal inflammation and architectural crypt distortions (ACD) are crucial for diagnosing ulcerative colitis (UC).
• ACD is typically defined by irregularly arranged, dilated, branched, and shortened crypts with uneven inter-crypt distances.
• Previous studies indicate diagnostic UC biopsies are often crosscut, a factor not typically considered in ACD assessment.

Purpose of the Study:

• To review and define the various crypt phenotypes encompassed within the concept of ACD in UC.
• To highlight the importance of considering crypt phenotypes and sectioning modes in the histologic diagnosis of UC.
• To enhance the understanding of ACD interpretation in crosscut UC biopsy sections.

Main Methods:

• Review of existing literature and definitions of architectural crypt distortions in ulcerative colitis.
• Categorization and description of diverse crypt phenotypes observed in UC histology.
• Analysis of the implications of crosscutting on the interpretation of crypt morphology.

Main Results:

• ACD in UC includes various crypt phenotypes such as asymmetric branching, crypt rings, lateral buds, 'kissing crypts,' crypts-in-crypts, and laterally oriented crypts.
• Irregularly shaped and sized crypts in specific domains also contribute to the ACD notion.
• Recognizing these diverse phenotypes is vital for accurate interpretation of crosscut UC biopsy sections.

Conclusions:

• Awareness of disparate crypt phenotypes contributing to ACD can improve the interpretation of UC histology.
• This understanding offers new perspectives for pathologists evaluating crypt distortions in UC diagnostic sections.
• The findings aim to improve diagnostic accuracy and clinical understanding of ACD in ulcerative colitis.