대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Mediastinal tb. lymphadenitis with esophagomediastinal fistula

Radiologic Findings

A 26-year-old man presented with fever, cough, and weight loss for two months. Serological test for HIV was positive. Many acid-fast bacilli were found in his sputum. Chest radiograph shows an infiltration in the right upper lung zone with mediastinal widening. CT scans show diffusely enlarged mediastinal lymph nodes that have irregular low density internally and rim enhancement. An irregularly shaped gas collection is seen in the right subcarinal area, which communicates with esophageal gas. An esophagogram with gastrografin (not shown) showed a fistulous communication between the esophagus and the gas-filled space. After two months of anti-tuberculous medication, the right upper lung zone infiltration and mediastinal bulging showed marked improvement. Esophagogram was normal. The patient died of mixed Pneumocystis carinii pneumonia and cytomegalovirus infection 3 months later.

Brief Review

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

Keywords

Mediastinum, Esophagus, Infection, Bacterial infection, tuberculosis, Mediastinal tuberculous lymphadenitis with esophagomediastinal fistula