Colonic Tuberculosis

Abstract

Purpose: Introduction: Gastrointestinal tuberculosis is an unusual disease in the West. However, in recent years there has been a resurgence of colonic tuberculosis in the U.S. secondary to the high influx of immigrants from high-risk areas and the rising AIDS population. We report the cases of 3 patients from endemic countries diagnosed with colonic tuberculosis by colonoscopic biopsy. Case Descriptions: Case 1 – A 29 year old female presented with lower abdominal crampy pain, fever, constipation, weight loss, and iron deficiency anemia. Physical examination was normal except for heme positive stool. Abdominal CT showed marked transmural, circumferential wall thickening of the cecum and proximal ascending colon and local lymphadenopathy. On colonoscopy, a partially obstructing tumor of the hepatic flexure was noted. The pathology report described moderate chronic and moderate active typhlitis with granulomata. The endoscopist was called when cecal biopsy cultures were surprisingly positive for Mycobacterium Tuberculosis. Case 2 – A 33 year old male presented with right lower quadrant abdominal pain, weight loss, nausea, and vomiting. A small bowel follow-through revealed high grade partial small bowel obstruction. On colonoscopy, discontinuous areas of bluish nodular ulcerations were noted in the mid-transverse colon. Initially, these findings were suspicious for Crohn's disease. Biopsies revealed a mixture of histologic alterations including crypt architecture distortion, well-formed, non-necrotizing granulomas in all layers of the bowel, and active inflammation with erosions. No microorganisms were seen on acid-fast stains, but cultures returned positive for M. Tuberculosis. Case 3 – A 65 year old Indian male presented with abdominal cramps and melanotic stools. Physical examination was again normal except for heme positive stool. He was found to have iron deficiency anemia. Colonoscopy revealed a 3 × 1 cm nodular mass in the left transverse colon. The pathology report described granulomatous inflammation. Stains for acid-fast bacilli were negative, but cultures were again positive for M. Tuberculosis. Discussion: Given the vagueness of its signs and symptoms, the diagnosis of colonic tuberculosis can be difficult and requires a high index of suspicion, especially in the immigrant population. Colonoscopy is essential in making the diagnosis. Endoscopic appearance often mimics Crohn's disease or malignancy. Early recognition and biopsies sent appropriately for histology and culture for tuberculous bacilli are key to diagnosis. In light of the changing epidemiology of the disease in recent years, clinicians in the U.S. must be prepared to recognize its features in order to diagnose and treat this entity.