Tuberculous colitis

 CLINICAL HISTORY

An 18-year-old girl complained of right lower quadrant pain, subfebrile temperature, nausea, general weakness, anorexia, and diaphoresis. Routine chest x-ray showed bilateral upper lobe opacity. Chest and abdominal CT were performed using oral and intravenous contrast.

FINDINGS

FIGURES 1 and 2. Continuous chest CT with IV contrast shows bilateral upper lobe consolidation surrounded by small (2 to 3 mm) diffuse nodules.

FIGURE 3. Abdominal CT with IV contrast shows diffuse wall thickening in right colon with mild contrast enhancement and mesenteric lymph nodes.

FIGURE 4. Coronal abdominal multiplanar reformatting shows marked wall thickening to the cecum and ascending colon.

DIFFERENTIAL DIAGNOSIS

The appearance of the cecum and ascending colon on CT suggested differential diagnoses of ischemic, inflammatory, or infiltrative mass. The acute onset of disease and the presence and appearance of lymph nodes only in the mesenteric region ruled out lymphoma.

The patient is young and did not report any major hypotensive episodes, and her mesenteric vessels were patent. Ischemic colitis was consequently excluded. Inflammatory diseases, such as ulcerative colitis and Crohn's disease, were considered unlikely, given the absence of inflammatory changes in pericolonic fat, the degree of wall thickening, and the lack of other suggestive CT findings.^1,2

Changes to the lung seen on CT supported the diagnosis of tuberculous colitis.

DIAGNOSIS

Tuberculous colitis. Bronchial lavage for bacillus of tuberculosis was positive. Colonoscopy revealed hyperemia and widespread erosion, though it was difficult to perform a full evaluation of the entire cecum and terminal ileum. The patient's pain was relieved some days after treatment with antitubercular drugs. Continued treatment with antitubercular drugs has led to a dramatic improvement in her clinical situation.

DISCUSSION

Gastrointestinal involvement by tuberculosis is very rare. It is most often seen in immunocompromised patients or in areas where the disease is epidemic. The ileocecal region is most likely to be affected, owing to the richness of lymphoid tissue.

The classic appearance on CT is concentric colonic wall thickening, mostly in the right colon and terminal ileum, associated with mesenteric adenopathy. Lymph nodes are enlarged and demonstrate centralized low attenuation or are calcified.

The natural history of colonic tuberculosis includes ulceration, hypertrophy, or both ulceration and hypertrophy, leading to scarring or masslike lesions. This is reflected in imaging findings.

Definitive diagnosis can be made from endoscopic examination (biopsy or laparoscopy) showing the presence of caseating granuloma or positive culture for acid-fast bacillus.^2,3 Accurate identification of tuberculous colitis and early treatment will lead to a favorable outcome.

Case submitted by Prof. Maksim Cela, department of radiology, University Hospital "Mother Teresa," and Dr. Fatmir Bilaj, Medicare Diagnostic Center, Tirana, Albania.

References

1. Macari M, Balthazar EJ. CT of bowel wall thickening: significance and pitfalls of interpretation. AJR 2001;176(5):1105-1116.
2. Thoeni RF, Cello JP. CT Imaging of colitis. Radiology 2006;240(3):623-638.
3. Harisinghani MG, McLoud TC, Shepard JA, et al. Tuberculosis from head to toe. Radiographics 2000;20(2):449-470.