Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Giant-cell interstitial pneumonia
- Radiologic Findings
- Initial HRCT demonstrates patchy ground-glass opacities in peripheral portion of both lungs. Follow up HRCT after 3 months shows patchy and centrilobular ground-glass opacities in both lungs.
Pathologic specimen obtained with video-assisted thoracoscopic surgical biopsy in the lower lobe of the right lung shows macrophages with multinucleated giant cells and peribronchiolar fibrosis.
- Brief Review
- Hard metal is an alloy of tungsten carbide and cobalt, sometimes mixed with other metals. Of these, at least cobalt is toxic to the lung. Exposure to aerosolized particulates containing cobalt inhaled during the manufacture or grinding of hard metal results in interstitial inflammation with fibrosis and lung destruction, which may develop within a few years of exposure. The histologic appearance of hard metal pneumoconiosis has been termed giant cell interstitial pneumonia.
The clinical features of GIP are nonspecific. Patients complain of shortness of breath, cough and dyspnea on exertion. Generally, if exposure is avoided, patients improved in symptoms and physiologic study, although residual lesions tend to persist.
HRCT findings include ground-glass opacity, coarse reticular opacities, consolidation, architectural distortion, traction bronchiectasis and bronchiolectasis, and subpleural bullae. The presence of ground-glass opacity and reticulation are most common, but honeycombing may occur with disease progression. These CT findings correspond histopathologically to areas of interstitial thickening caused by fibrosis and inflammatory cell infiltration and to areas of intra-alveolar accumulation of macrophages and multinucleated giant cells. The distribution may be patchy or with upper or lower lobe predominance.
The histopathologic manifestations of hard-metal disease range from bronchitis to subacute fibrosing alveolitis to interstitial fibrosis. Obliterative bronchiolitis is reported to be the earliest manifestation of hard-metal disease. Subacute fibrosing alveolitis is characterized by the desquamation of epithelial cells and the accumulation of macrophages and multinuclear giant cells in the alveolar spaces within a few years of initial exposure, whereas chronic diffuse mural fibrosis with honeycombing occurs several years or more after initial exposure.
- References
- 1. Webb, WR, Muller, NL, Naidich, DP High resolution computed tomography findings of lung disease, 4th eds. 2009,329 Lippincott William & Wilkins. Philadelphia, PA.
2. Lee SM, Moon CH, Oh YB, et al. Giant-cell interstitial pneumonia in a gas station worker. J Korean Med Sci1998 ;13:545 -547
3. Pakes WR. Cobalt. In: Pakes WR, ed. Occupational lung disease. London, England: Butterworths, 1982; 464
- Keywords
- lung, inhalation, Occupational lung disease,