대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Pneumoconiosis with PMF and tuberculosis (Silicotuberculosis)

Radiologic Findings

Brief Review

The characteristic radiologic abnormality seen in patients with both silicosis and coal worker's pneumoconiosis consists of small well-circumscribed nodules usually measuring 2 to 5 mm in diameter, but ranging from 1 to 10 mm, mainly involving the upper and posterior lung zones. As the process advances, the nodules increase in size and number and become more widespread, involving all zones. Sometimes the nodules are calcific. Focal emphysema surrounding the nodule is common. The appearance of large opacities, also known as conglomerate masses or progressive massive fibrosis, indicates the presence of complicated pneumoconiosis. The masses tend to develop in the midportion or periphery of the upper lung zones and migrate toward the hila, leaving overinflated emphysematous spaces between the conglomerate mass and the pleura. Progressive massive fibrosis of pneumoconiosis may be not easily distinguished from the lung cancer and tuberculosis. In PMF of pneumoconiosis, mass usually shows bilateral symmetric appearance with slow progression and appear emphysematous change outside the mass. There appears to be little question that silicosis predisposes to tuberculosis. One study shows that silicon not only injured cell membrane, cytoplasm and nucleus membrane, but also inhibite the activity of succinic dehydrogenase in monocytes and lung tissue. In such condition, the tubercle bacilli become easier to grow. The radiologic findings of tuberculosis developed in the patients with silicosis include pleural effusion, newly-developed consolidation, bronchovascular infiltrations, cavitary change in pre-existing PMF, etc.

References

Keywords

Lung, Inhalation and aspiration disease, Occupational lung disease, tuberculosis, Pneumoconiosis with PMF and tuberculosis (Silicotuberculosis)