대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Fibrosing Mediastinitis

Radiologic Findings

Chest radiograph shows fine reticular opacities in the entire right lung, focal area of consolidation in the right lower lobe, and increased interstitial markings on the left lung. Contrast-enhanced CT scans show soft tissue lesion in the right anterior mediastinum with obstruction of the superior vena cava, right pulmonary veins, and right pulmonary artery. There is no evidence of contrast enhancement in these anatomic structures. Also note collateral veins in the anterior chest wall, small right pleural effusion, and the dilated and enlarged pulmonary trunk and left pulmonary artery.
High-resolution CT scan shows thickening of the interlobular septa and major fissure, multifocal areas of ground-glass attenuation which were presumed to represent interstitial pulmonary edema, and the dilated left pulmonary artery and its branches suggesting diversion of pulmonary arterial blood flow.
These findings suggest fibrosing mediastinitis, localized pattern, which was confirmed with pathologic examination on open thoracotomy. Infectious etiology could not be identified on pathologic, clinical, and laboratory evaluation.

Brief Review

Fibrosing mediastinitis (FM) is an excessive fibrotic reaction that occurs in the mediastinum, most commonly secondary to histoplasmosis. This fibrotic reaction may lead to compression and sometimes occlusion of mediastinal structures. Other granulomatous diseases such as tuberculosis have reportedly resulted in FM. Several examples of an idiopathic form of
FM perhaps due to a noninfectious, possibly autoimmune process have also been described. This idiopathic form is occasionally associated with other conditions, including retroperitoneal fibrosis, orbital pseudotumors, Riedel's sclerosing thyroiditis, and methysergide therapy.
Two different radiographic patterns were identified: a localized pattern that frequently contained calcification and a diffuse pattern that did not contain calcification. The localized pattern is most likely due to histoplasmosis and does not show radiographic evidence of improvement with steroid therapy. The diffuse pattern may more likely be truly idiopathic
or of a noninfectious etiology. Some patients with diffuse pattern show radiographic evidence of improvement with steroid therapy.

References

1. Sherrick AD, Brown LR, Harms GF, Myers JL. The radiographic findings of fibrosing mediastinitis. Chest 1994;106:484-489
2. Lee JY, Kim Y, Lee KS, Chung MP. Tuberculous fibrosing mediastinitis: radiologic findings [letter]. AJR 1996;167:1598-9
3. Weinstein JB et al. CT of fibrosing mediastinitis: findings and their utility. AJR 1983;141:247-51
4. Ramakantan R et al. Dysphagia due to mediastinal fibrosis in advanced pulmonary tuberculosis. AJR 1990;154:61-63

Keywords

Mediastinum, Non-infectious inflammation,