The Usefulness of Colonoscopic Biopsy in the Diagnosis of Intestinal Tuberculosis and Pattern of Concomitant Extra-intestinal Tuberculosis

Lee, Yun Jung; Yang, Suk Kyun; Myung, Seung Jae; Byeon, Jeong Sik; Park, Il Gwon; Kim, Jung Sun; Lee, Gin Hyug; Jung, Hwoon Yong; Hong, Weon Seon; Kim, Jin Ho; Min, Young Il

Abstract

BACKGROUND/AIMS: Intestinal tuberculosis can be difficult to diagnose because it may mimic many other intestinal diseases. The aim of this study was to evaluate the diagnostic yield of colonoscopic biopsy and frequency of concomittent extra-intestinal tuberculosis in intestinal tuberculosis. METHODS: The medical records of 225 consecutive patients with intestinal tuberculosis (81 men, 144 women; mean age 40.6 yrs) were analyzed retrospectively. RESULTS: Histological examination of colonoscopic biopsy specimens revealed granulomas in 163 (72.4%) of the 225 patients. However, caseous necrosis was found in only 25 (11.1%) patients, and acid-fast bacilli (AFB) were noted in 39 (17.3%) of the 225 patients. Mycobacterium tuberculosis was isolated from the culture of biopsy specimens in 52 (29.3%) of 177 patients. Eighty-four patients (37.3%) had concomitant extra-intestinal tuberculosis and 67 (29.8%) showed active pulmonary tuberculosis. Histological examination of the biopsy specimens enabled the diagnosis of intestinal tuberculosis by the presence of either caseating granulomas or AFB in 52 (23.1%) patients. Combination of histological examination and Mycobacterium culture established the diagnosis in 87 (38.7%) patients. Before getting the result of Mycobacterium culture, the diagnosis could be made, by either histological examination or the presence of extra-intestinal tuberculosis in 107 (47.6%) patients. Combination of caseating granulomas, AFB staining, Mycobacterium culture, and the presence of extra-intestinal tuberculosis resulted in the diagnosis in 126 (56.0%) patients. CONCLUSIONS: To increase the diagnostic yield, AFB staining and Mycobacterium culture should be routinely performed on biopsy specimens in addition to routine histological examination for caseating granulomas.