A Systematic Approach to the Histologic Evaluation of Terminal Ileal Biopsies

Area of Science:

• Gastroenterology
• Surgical Pathology
• Diagnostic Histology

Background:

• Ileal biopsies are vital for diagnosing Crohn's disease (CD).
• The ileal mucosa presents diverse nonneoplastic and neoplastic conditions mimicking CD.
• Accurate interpretation necessitates understanding normal histology, variants, and diagnostic algorithms.

Purpose of the Study:

• To outline the range of ileal pathologies.
• To establish a systematic diagnostic strategy for ileal biopsies.
• To identify diagnostic pitfalls and limitations in ileal biopsy interpretation.

Main Methods:

• MEDLINE literature review on ileal pathology.
• Incorporation of institutional clinical-pathologic insights.
• Critical analysis of diagnostic criteria, differentials, and evolving concepts.

Main Results:

• Ileal conditions include tropical sprue, eosinophilic enteritis, graft-versus-host disease, tuberculosis, and neoplasms.
• Drug-induced injuries (NSAIDs, immunotherapy) are significant differentials.
• Mimicking conditions necessitate careful histological evaluation.

Conclusions:

• Systematic histologic evaluation integrated with clinical, endoscopic, and imaging data is paramount.
• This approach minimizes diagnostic errors, especially differentiating CD from overlapping conditions.
• Recognizing histologic variations and employing a comprehensive strategy enhances diagnostic yield and guides management.