Intestinal tuberculosis: clinicopathologic analysis and diagnosis by endoscopic biopsy

Tuberculosis is still an important cause of granulomatous colitis in developing countries. If we can diagnose tuberculosis using endoscopic biopsy material, clinicians can avoid invasive diagnostic procedures and needless operations. For this purpose, we evaluated clinical manifestations, pathological findings, and diagnostic methods in endoscopically biopsied intestinal tuberculosis patients.

From January 1991 to December 1996, 42 patients with intestinal tuberculosis were endoscopically examined and tissue culture, immunohistochemical stain, Ziehl-Neelsen stain, and polymerase chain reaction in fresh and fixed tissue were applied. The pathological findings were analyzed and compared with the results of the other diagnostic methods.

In tuberculosis patients, transverse ulcers with surrounding hypertrophic mucosa and multiple erosions were usual colonoscopic findings. The granulomas were found in 74% of the cases. The positivity ranged from 30-45%. There were no significant differences in the positivity among those diagnostic methods (p > 0.05). The positivity of Ziehl-Neelsen stain in fixed tissue was higher in the group having granulomas and it was reversed in PCR (p < 0.05). The increasing number of biopsy particles raised the positivity of Ziehl-Neelsen stain and PCR in fixed tissue (p < 0.05).

Transverse ulcers were the most characteristic colonoscopic finding and granulomas were frequent pathological findings in intestinal tuberculosis. Higher positivity and reliable results were found in tissue culture, Ziehl-Neelsen stain, and polymerase chain reaction. To increase the diagnostic rate, the endoscopist should take enough tissue and deep biopsy material from ulcer bases and diseased mucosae.