An Incidental Finding of Primary Colonic Tuberculosis Disguising Itself as Colon Cancer

Abstract

Intestinal tuberculosis (TB) is common among the extrapulmonary spectrum of TB seen in developing countries, with the ileocecal region being the most common site involved. Isolated colonic TB is rare among intestinal TB. The usual presentation of intestinal TB is transverse ulceration, which should be differentiated from other causes of intestinal ulcers. The diagnosis of isolated colonic TB is challenging due to a lack of typical clinical presentations and nonspecific colonoscopy findings. There are myriad histomorphological features seen in the intestinal tuberculosis, including epithelioid cell granulomas with or without necrosis and extensive fibrosis with stricture formation and sometimes only show dense mixed inflammatory cells comprising polymorphs and histiocytes. It can also be presented as spindle cell pseudotumors. The acid-fast bacilli in biopsy specimens are not frequently encountered. Hence, the diagnosis of intestinal TB is missed most of the time in the early stages, and the patient lands up in an emergency. Here, we would like to add another case of colonic TB to the literature, wherein a 60-year-old female who was asymptomatic for 1 month suddenly presented with acute symptoms of intestinal obstruction and was misdiagnosed clinically as well as radiologically as colonic carcinoma. The diagnosis of tubercular colitis was later confirmed on histopathological examination of the hemicolectomy specimen.

Keywords

• acid-fast bacilli
• colonic cancer
• confluent epithelioid cell granulomas
• gastrointestinal tuberculosis
• isolated colonic tuberculosis
• mycobacteria