Case report: colonic tuberculosis mimicking crohn’s disease: importance of histological examination

Abstract

There has been a rise in gastrointestinal tuberculosis incidence among immigrants and HIV patients, both in Europe and the United States. However, abdominal tuberculosis is very uncommon in Australia. The diagnosis of tuberculosis may be overlooked due to lack of experience and the fact that one type of tuberculosis, hypertrophic tuberculous colitis (HTC), can mimic Crohn's disease colonoscopically and radiologically. The ileocaecal region and peritoneum are the most likely sites of infection. Pulmonary tuberculosis is evident in less than half of patients. We present a case of HTC in a 29-year-old Indian man presenting with right iliac fossa pain. Appendicectomy was embarked upon but was converted to right hemicolectomy on intraoperative suspicion of pathology – Crohn's disease or tuberculosis. Macroscopically there were severe cobblestone skip lesions in the colonic mucosa, with fissures penetrating into the muscularis propria. Necrotising granulomatous inflammation on microscopic examination and positive mycobacterium species nucleic acid amplification test (PCR) confirmed the tuberculous colitis. This case emphasises the significance of histopathological examination in guiding and validating the management, as the administration of corticosteroids (for the treatment of the Crohn's disease) to a patient with colonic tuberculosis may have disastrous results.