대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Esophagobronchial Fistula due to Tuberculosis

Radiologic Findings

Subcarinal and right hilar lymph node enlargement,
Deformity of esophagus and irregular esophageal wall thickening,
Deformed esophageal gas with some feature of cleft,
Ill-defined airspace consolidation, ground-glass attenuation, and centrilobular nodules in RLL (aspiration pneumonia).

The following esophagogram shows an irregular fistulous tract between the dilated esophagus and the bronchus.

Brief Review

Tuberculous mediastinal lymphadenopathy is an infrequent occurrence (about 4.4%) in adults, because aquired resistance enhances the ability of subjects to confine organisms to the site of infection. There is some female preponderance of 2~3:1. Right sided mediastinal lymph nodes are more commonly involved because the preferential lymph flow of entire right lung and left upper lung to right tracheobronchial and paratracheal nodes as well as the higher frequency of right lung pulmonary tuberculosis involvement. The involved lymph nodes show necrotic central low attenuation area and enhanced peripheral portion due to inflammatory hypervasculaity on enhanced CT scan.

Esophageal involvement by tuberculosis usually occurs in the late stages of tuberculosis secondary to pulmonary, mediastinal, or disseminated disease. Direct contiguous involvement from adjacent tuberculous lymphadenitis is known to be the most frequent cause of esophageal tuberculosis. On contrast enhanced CT, these lymph nodes typically show central low density with peripheral rim enhancement representing caseation necrosis and hyperemic granulation tissue, respectively. Necrotic material within the tuberculous mediastinal lymph node can be extruded through an esophageal and/or tracheobroncheal fistula, resulting in a localized gaseous collection within the mediastinum. Even though tuberculous lymphadenitis involves right paratracheal nodes more commonly than subcarinal nodes, as the diseased right paratracheal nodes have less chance to contact the esophagus than the subcarinal nodes, fistulous communication is more prone to occur in the subcarinal area.

In contrast to the poor prognosis associated with esophageal rupture by forceful vomiting or by other trauma, esophageal perforation by tuberculous esophagomediastinal fistulas tends to close uneventfully during anti-tuberculous therapy.

References

1. JG Im, KS Song, HS Kang, et al. Mediastinal tuberculous lymphadenitis: CT manefestations. Radiology 1987;164:115-119

Keywords

Lung, Esophagus, Infection, Bacterial infection, tuberculosis,