Two cases of colonic tuberculosis presenting with massive melena

The clinical symptoms of colonic tuberculosis are variable, among which massive melena is extremely rare. Herein, we report two cases of colonic tuberculosis representing with massive melena, both of whom never had active pulmonary tuberculosis. The first case was a 55-year-old woman. Although her emergency colonoscopic setting suggested colonic tuberculosis, no evidence of tuberculosis could be found at that time. We performed a therapeutic trial and observed a drastic regression of the initial changes with 4-week treatment using antituberculous agents. The second case was a 37-year-old man. His emergency colonoscopy showed lesions mimicking colon carcinoma. However, the histological examinations did not indicate malignancy. The polymerase chain reaction of colonic biopsy specimen was positive for Mycobacterium tuberculosis. Similar to the first case, a significant improvement of the initial lesions was observed after 4-week treatment using antituberculous agents. Collectively, although the massive melena is a rare manifestation, tuberculosis of the colon should be suspected in the patients with such symptom.