Neural patterns in inflammatory bowel disease: an immunohistochemical survey.

The differential diagnosis of inflammatory bowel disease remains a significant diagnostic problem for surgical pathologists. Neural abnormalities, such as hypertrophy of nerve plexi, hyperplasia of ganglion cells, and ultrastructural axonal degeneration have been described in patients with regional enteritis. We performed an immunohistochemical survey of forty cases of regional enteritis, ulcerative colitis, nonspecific colitis, and normal colon. A panel of antibodies, directed against neuron-specific enolase, S-100 protein, synaptophysin, neurofilament protein, and nerve growth factor receptor, was utilized to evaluate the distribution of nerve fibers in paraffin-embedded tissue. Anti-synaptophysin and anti-nerve growth factor receptor highlighted small, arborizing nerve fibers in the mucosa, not apparent in the routinely stained sections. Intense staining of these fibers was observed in regional enteritis with antinerve growth factor receptor. This antibody may aid the discrimination of inflammatory bowel disease from other causes of colonic inflammation and facilitate the identification of regional enteritis in endoscopic biopsies.