Biopsy of the terminal ileum is commonly performed during colonoscopy.
The primary utility of this is to diagnose or rule out Crohn's disease in patients with symptoms and/or radiographic findings suggesting this diagnosis.
Dr Barbara McKenna and colleagues from Michigan observed many such biopsies in their gastrointestinal pathology service and have been impressed by the subjectively low yield of terminal ileum biopsies.
Therefore, the team studied this to obtain objective data.
|Terminal ileum was histologically normal in 82%|
|The American Journal of Gastroenterology|
The researchers retrospectively reviewed 414 consecutive patients with terminal ileal biopsies.
Histologic parameters evaluated were primarily those changes diagnostic of chronic inflammation or its sequelae.
Histologic findings were then compared with the indication and endoscopic findings.
The research team found that the terminal ileum was histologically normal in 82% and endoscopically normal in 81%.
The team noted that 13% of endoscopic abnormals had ‘ileitis'.
Known or strongly suspected inflammatory bowel disease was the most common indication with Crohn's disease accounting for 20%.
The team found that ulcerative colitis accounted for 16% followed by diarrhea in 33%.
Other endoscopic abnormal causes included anemia or hematochezia in 15%, abdominal pain in 6%, and abnormal imaging in 5%.
Diagnostic yield varied, with indication and endoscopic findings being highest with known suspected Crohn's disease, and abnormal imaging.
In addition, endoscopes ‘ileitis', ulcers or erosions were also amongst the highest endoscopic findings.
Dr McKenna's team concluded, "Diagnostic yield of terminal ileum biopsy varied with indication and endoscopic findings."
"Biopsy is of greatest value in patients undergoing endoscopy for known or strongly suspected Crohn's disease, or with an abnormal imaging study of the terminal ileum."
"Biopsy of endoscopically normal mucosa is unlikely to yield diagnostically useful information, and is not encouraged as routine."
"However, when ‘ileitis', ulcers, or erosions are identified, biopsies can be very helpful."