British Journal of Radiology 74 (2001),1056-1058 © 2001 The British Institute of Radiology
CT and MRI appearance of a fistula between the right and left main bronchus caused by tracheobronchial tuberculosis
E Yilmaz, MD
1
A Akkoclu, MD
2 and
C Sevinc, MD
2
Departments of 1Radiology and 2Respiratory Medicine, Dokuz Eylül University Hospital, 
zmir, 35340, Turkey
Correspondence: Dr Erkan Yilmaz, Mithatpasa Cad. Tan Apt. No: 65/3, 35330 Balcova, zmir, Turkey
 |
Abstract
|
|---|
Tuberculosis of the trachea and main bronchi is a relatively rare disease seen predominantly in elderly patients. We present a case of a fistula between the right and left main bronchus owing to tuberculosis. We describe the CT and MRI appearances.
|
Introduction
|
|---|
Tuberculous disease of the trachea and main bronchi is a rare entity, much less commonly encountered than the other pulmonary forms [1]. Tracheobronchial tuberculosis usually involves the long segment of the airway. Bronchial stenosis is the most frequent complication of this entity[2]. The diagnosis is suggested on CT and MRI examination but requires confirmation by bronchoscopy and bacteriology. To our knowledge, a fistula between the right and left main bronchus caused by tracheobronchial tuberculosis has not been previously reported. We present a case of interbronchial fistula in a woman and describe the CT and MRI findings.
|
Case report
|
|---|
A 76-year-old woman was admitted to hospital with a 3-month history of persistent cough, weakness, weight loss and fever. Chest radiography on admission was normal. CT showed an irregular inner surface to the walls of the proximal main bronchi. A retrocaval lymph node 1 cm in diameter was present. There was no evidence of mediastinal inflammation. In addition, an air-filled fistulous connection between the bronchi, just below the carina, was noted (Figure 1
). MRI, performed to delineate the fistula in more detail and to assess the peribronchial areas and surrounding soft tissues, showed marked wall thickening of the distal trachea extending to both proximal main stem bronchi, with an irregular luminal surface (Figures 2 a,b).
View larger version (161K):
[in this window]
[in a new window]
|
Figure 1. CT with coronal reformatting of the airways shows an air-containing connection (black arrowhead) between the proximal main bronchi, with mild luminal narrowing adjacent to the involved bronchi. Note the position of the carina (open arrow).
|
|
View larger version (41K):
[in this window]
[in a new window]
|
Figure 2. (a) Coronal and (b) axial T1 weighted MR images show a fistulous tract (white arrow) just below the carina (open arrow). Note the uneven mural thickening of the airways through the distal trachea and proximal main bronchi (arrowheads).
|
|
Skin test to purified protein derivative was strongly positive. On bronchoscopy, slight narrowing and marked irregularity of the distal trachea with widespread patchy congestion and ulceration of the mucosa was found. A necrotizing, glistening, yellowish lesion with a conspicuous opening into the left main bronchus, representing a fistulous tract, was observed at the origin of the medial surface of the right main bronchus (Figure 3a). The presence of tuberculous bacilli by stain as well as microscopic findings of tuberculous inflammation were identified on transbronchial biopsy material (Figure 3b). The patient was treated conservatively with antituberculous therapy for 6 months. Follow-up bronchoscopy showed regression of the endobronchial lesion, although a thinned remnant of the fistulous tract was still present.
View larger version (65K):
[in this window]
[in a new window]
|
Figure 3. (a) Bronchoscopy shows widespread ulceration of the tracheobronchial mucosa and a yellow lesion with caseating material adjacent to the opening site of the right main lobe bronchus. A fistula (arrow) extending from the left main bronchus towards the right main bronchus (asterisk) is also seen. (b) Photomicrograph of the bronchial brushing material with acid-fast staining shows Mycobacterium tuberculosis bacilli (arrowheads) (Ziehl–Neelsen stain, x 100).
|
|
|
Discussion
|
|---|
Tracheobronchial tuberculosis has been reported in 10–20% of all patients with pulmonary tuberculosis [3]. With improved treatment, tuberculosis of the trachea and main bronchi have decreased in frequency, paralleling the overall decline in tuberculosis. The distal portion of the trachea has been known to be a common site and the carina is always involved. Lymphadenopathy is usually associated with active disease. Tracheobronchial involvement has always accompanied parenchymal tuberculosis, suggesting implantation of acid-fast bacilli or lymphatic submucosal spread of the infection to the trachea and main bronchi from parenchymal lesions [4]. Tracheal disease begins as simple erythema and oedema with lymphocytic infiltration of the submucosa followed by tubercle formation. Extensive granular tissue formation, destruction and replacement of the mucosa and submucosa, and subsequent fibrosis may result in tracheobronchial narrowing, which is the most frequent late complication [3, 4]. Fistulae due to pulmonary tuberculosis are rare and are usually bronchopleural [5]; some may be encountered after thoracic surgery or as oesophagobronchial fistulae [6] due to mediastinal tuberculous lymphadenitis, especially in children. Both blunt and penetrating trauma may cause a bronchopleural fistula. Fistulous connection between the tracheobronchial tree and the aorta is very rare and has been reported secondary to aortic aneurysmal or graft erosion of the tracheobronchial wall [7].
CT shows irregular airway narrowing, luminal obstruction, enlarged mediastinal lymph nodes and associated parenchymal changes. Multiplanar reconstructed and three-dimensional images give more information for the evaluation of central airways, particularly for showing focal stenosis of the airways and the longitudinal extent of bronchial lesions. These images also provide a guide for surgical planning and follow-up evaluation of treatment response [4]. MRI is helpful in evaluating the airway lumen, the contour and thickness of the tracheobronchial wall, peribronchial soft tissues, and mediastinal structures with multiplanar images [4, 8].
CT and MRI findings of central airway tuberculosis are non-specific and need to be distinguished from bronchogenic carcinoma affecting the central bronchi or inflammatory granulomatous lesions such as amyloidosis, Wegener's granulomatosis and sarcoidosis. Radiological findings should always be supplemented by bronchoscopy to confirm the diagnosis. With treatment, complete or nearly complete resolution of the airway disease is possible in active disease [5, 9]. We believe that antituberculous therapy is the treatment of choice for tuberculous fistulae and that surgical intervention should not be considered in such cases.
Received for publication January 26, 2001.
Revision received May 17, 2001.
Accepted for publication June 19, 2001.
|
References
|
|---|
-
Moon WK, Im JG, Yeon KM, Han MC. Tuberculosis of the central airways: CT findings of active and fibrotic disease. AJR 1997;169:649–53.[Abstract/Free Full Text]
-
Choe KO, Jeong HJ, Sohn HY. Tuberculous bronchial stenosis: CT findings in 28 cases. AJR 1990;155:971–6.[Abstract/Free Full Text]
-
Shalutko ML, Kazak TI, Tarasov AS. Tuberculosis. In: Lukomsky GI, Tetarchenko VE, editors. Bronchology. St Louis, MO: Mosby, 1979;287–305.
-
Kim Y, Lee KS, Yoon JH, Chung MP, Kim H, Kwon OJ, et al. Tuberculosis of the trachea and main bronchi: CT findings in 17 patients. AJR 1997;168:1051–6.[Abstract/Free Full Text]
-
Donath J, Khan FA. Tuberculous and posttuberculous bronchopleural fistula. Ten year clinical experience. Chest 1984;86:697–703.[Abstract/Free Full Text]
-
Raghu G, Dillard D. Esophagobronchial fistula and mediastinal tuberculosis. Ann Thorac Surg 1990;50:647–9.[Abstract]
-
Masjedi MR, Davoodian P, Forouzesh M, Abttahi SJ. Broncho-aortic fistula secondary to pulmonary tuberculosis. Chest 1988;94:199–200.[Abstract/Free Full Text]
-
Webb EM, Elicker BM, Webb WR. Using CT to diagnose nonneoplastic tracheal abnormalities: appearance of the tracheal wall. AJR 2000;174:1315–21.[Free Full Text]
-
Bhatia R, Mitra DK, Mukherjee S, Berry M. Bronchoesophageal fistula of tuberculous origin in a child. Pediatr Radiol 1992;22:154.[Medline]
Top
Abstract
Introduction
