Tuberculous mediastinal lymphadenopathy in adults is infrequent in Japan and in western countries. The frequency of hilar and mediastinal lymphadenitis is less than 5% in Japan and 4.4% in the United States among tuberculosis patients, with a female-to-male predominance of 2.8:1. 4,5 Tuberculous mediastinal lymphadenitis without pulmonary lesion is much more rare in adults. 2,3 In contrast, the incidence of tuberculosis in Pakistan and India is approximately 20 times higher than in western countries. It is recognized that tuberculous mediastinal lymphadenopathy in these countries is more frequent than in the West. 6 Tuberculosis is one of the important causes of mediastinal lymphadenopathy in these countries. It is likely that tuberculous mediastinal lymphadenitis in adults is usually a manifestation of primary tuberculosis, as it is in children; however, reactivation of a latent nodal focus probably accounts for some cases. 2 As evidenced by our patient, the right tracheobronchial region has been reported to be the most commonly affected site. 2,7 Previous studies demonstrated that right intrathoracic lymphatic vessels combine and form a main truncus, whereas left lymphatic vessels lead individually to the thoracic duct. 8 Because there is considerable left-to-right crossover of lymphatic drainage but much less from right to left, right tracheobronchial adenopathy is common. 2 Contrast-enhanced computed tomographic findings of nodules with central low attenuation and peripheral rim enhancement corresponding pathologically to caseation or liquefaction necrosis and granulation tissue with inflammatory hypervascularity respectively are indicators of active tuberculous disease. 9,10 Enlarged lymph nodes with a low attenuation center are also seen in other diseases such as metastatic malignancy and pyogenic infection, whereas lymphomatous adenopathy characteristically shows homogeneous attenuation. 11 Gallium-67 scanning is a useful method for the detection of active inflammatory lesions and is sensitive for determining the localization of extrapulmonary tuberculosis. 12 The tracheal lesion was not detectable by conventional computed tomography. Obviously, bronchoscopic biopsy is necessary for the diagnosis of the tracheal polypoid lesion such as adenoma, carcinoma, inflammatory polyp, benign tumor, and amiloidoma. 13 In our patient the tracheal lesion had a smooth surface and looked like an inflammatory polyp. A histologic approach was reserved because of the chance of infection spreading to other patients. The tracheal polypoid lesion disappeared after 10 months of antituberculosis treatment, suggesting that this lesion was associated with chronic inflammation of tuberculous lymphadenopathy. Many patients with bronchial tuberculosis have few acid-fast bacilli in the sputum and have tuberculous lesions confined predominantly to the submucosa. 14 Perforation of the hilar lymph nodes into the bronchi 15 and spread to the intercostal chest wall have been reported previously. 4 Careful observation is recommended, particularly because of initial exacerbation induced by antituberculosis chemotherapy. In our patient, no serious complications or drug side effects were observed.
1. Raviglione MC, Snider Jr, DE Kochi A. Global epidemiology of tuberculosis
: morbidity and mortality of a worldwide epidemic. JAMA 1995; 273:220–6.
2. Amorosa JK, Smith PR, Cohen JR, et al. Tuberculous mediastinal lymphadenitis
in the adult. Radiology 1978; 126:365–8.
3. Liu CI, Fields WR, Shaw CI. Tuberculous mediastinal lymphadenopathy in adult. Radiology 1978; 126:369–71.
4. Okazaki M, Tomioka H, Hasegawa T, et al. A resected case of mediastinal tuberculous lymphadenitis with pericostal tuberculosis
. Kekkaku 1989; 65:293–7.
5. Shivpuri DN, Ban B. Tuberculous hilar and mediastinal adenitis. Am Rec Tuberc 1957; 76:799–810.
6. Irving HC, Brown TS. Tuberculous mediastinal lymphadenopathy in Bradford. Clin Radiol 1980; 31:685–90.
7. Baran R, Tor M, Tahaoglu K, et al. Intrathoracic tuberculous lymphadenopathy: clinical and bronchoscopic features in 17 adults without parenchymal lesions. Thorax 1996; 51:87–9.
8. Nohl HC. The spread of carcinoma of the bronchus.
London: Lloyd–Luke Ltd, 1962:17–44.
9. Im JG, Song KS, Kang KS, et al. Mediastinal tuberculous lymphadenitis: CT manifestations. Radiology 1987; 164:115–9.
10. Moon WK, Im JG, Yeon KM, et al. Mediastinal tuberculous lymphadenitis: CT findings of active and inactive disease. AJR Am J Roentgenol 1998; 170:715–8.
11. Yang ZG, Min PQ, Sone S, et al. Tuberculosis
versus lymphomas in the abdominal lymph nodes: evaluation with contrast-enhanced CT. AJR Am J Roentgenol 1999; 172:619–23.
12. Yang SO, Lee YI, Chung DH, et al. Detection of extrapulmonary tuberculosis
with gallium-67 scan and computed tomography. J Nucl Med 1992; 33:2118–23.
13. Hahn PY, Utz JP, Ingrassia III, T et al. Tracheobronchial amyloidoma. J Bronchol 2001; 8:112–3.
14. Kim Y, Lee KS, Yoon JH, et al. Tuberculosis
of the trachea and main bronchi: CT findings in 17 patients. AJR Am J Roentgenol 1997; 168:1051–6.
15. Suzuki K, Hayashi A, Yamagishi F, et al. A suspected case of perforation of lymph node into the bronchus during the treatment of adult hilar lymph node tuberculosis
. Kekkaku 1991; 67:127–31.
16. Chan CHS, Lai CKW, Leung JCK, et al. Elevated interleukin-2 receptor level in patients with active pulmonary tuberculosis
and the changes following anti-tuberculosis
chemotherapy. Eur Respir J 1995; 8:70–3.
17. Takahashi S, Setoguchi Y, Nukiwa T, et al. Soluble interleukin-2 receptor in sera of patients with pulmonary tuberculosis
. Chest 1991; 99:310–4.