대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Anthracofibrosis with blood clot and secretion

Radiologic Findings

Fig1, Initial chest AP shows golden S sign of RUL. It suggests RUL bronchial obstruction and parenchymal total collapse.

Fig2, chest CT shows beak-shaped narrowing of proximal Rt. Main bronchus and peribronchial enhancing soft tissue thickening.

Fig3, chest CT shows distal parenchymal atelectasis with intact internal vascular structures.

Fig4, coronal image shows proximal RUL obstruction and total atelectasis.

Brief Review

First radiologic differential diagnosis was endobronchial TB and peribronchial malignancy. We considered the possibility of malignancy to be low because the RUL bronchus shows smooth luminal narrowing, the internal vascular structures of collapsed lung are intact and there is no definite endobronchial enhancing mass. Bronchoscopy was performed to determine the cause of bronchial obstruction.

The findings of bronchoscopy showed anthracofibrotic changes in the diffuse bronchi, especially in the RUL bronchus, and obstruction with secretions and blood clots. When washing in RUL bronchus, some patency of the bronchial lumen was secured.

Brochial anthracofibrosis is a bronchoscopic finding, defined as luminal narrowing associated with anthracotic pigmentation without a relevant history of pneumoconiosis or smoking. The CT findings have been reported to include smooth bronchostenosis and peribronchial lymph nodes along with peripheral atelectasis. Because of this, it is not always easy to differentiate between two diseases such as bronchogenic carcinoma and endobronchial tuberculosis (TB). Especially, differentiation of anthracofibrosis from TB has been difficult. Because of the similar CT findings, endobronchial TB has been suggested as a mechanism underlying anthracofibrosis. For these reasons, empiric anti-TB medication may be helpful in the treatment of anthracofibrosis patients without evidence of active TB. Anthracofibrosis was more common than endobronchial TB among elderly patients. Statistically significant findings on CT were the pattern of bronchostenosis, the presence of main bronchus involvement, and number of pulmonary lobes involved. Bronchostenosis with anthracofibrosis usually involves multiple lobar or segmental bronchi. The main bronchus, however, tends to be preserved in anthracofibrosis. Most cases of endobronchial TB involve one lobar bronchus and the ipsilateral main bronchus with contiguity in extent.
However, for our patient, the right mainstem was involved and bronchial wall irregularity was not conspicuous, making it more difficult to differentiate.

References

1. Park HJ, Park SH, et al. CT differentiation of anthracofibrosis from endobronchial tuberculosis, AJR 2008; 191:247

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