Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Respiratory bronchiolitis-associated interstitial lung disease
- Radiologic Findings
- She was non-smoker but exposed to heavy cigarette smoke because she had been worked as waitress in pub.
Chest radiograph shows diffusely scattered fine micronodules in both entire lungs. HRCT scan show evenly distributed ill-defiend centrilobular nodules in both entire lungs.
Histopathlogic specimen obtained from video-assisted thoracoscopic surgical lung biopsy shows respiratory bronchiolitis pattern with marked alveolar macrophage accumulation in and around bronchioles, mild chronic inflammation of bronchioles, fibrous thickening of the wall of bronchioles, cuboidal cell hyperplasia of alveolar ducts and alveoli adjacent to the bronchioles, consistent with respiratory bronchiolitis-interstitial lung disease(RB-ILD)
- Brief Review
- Respiratory bronchiolitis is a pattern of lung injury occurring in cigarette smokers, characterized pathologically by accumulation of pigmented macrophages in respiratory bronchioles. It is commonly found as an incidental histologic abnormality in asymptomatic smokers and may be associated with CT findings of centrilobular nodularity and mild ground-glass attenuation. In some patients, the extent of alveolar accumulation and bronchiolar inflammation is severe enough to cause clinical, physiologic, and imaging features of interstitial lung disease. This clinicopathologic syndrome, called respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), occurs almost exclusively in heavy cigarette smokers. Since the clinical features of RB-ILD may be confused with other interstitial lung diseases such as idiopathic pulmonary fibrosis and the imaging features overlap with other entities such as hypersensitivity pneumonitis, the diagnosis is often made on open or thoracoscopic lung biopsy.
The chest radiographic findings of patients with RB-ILD include reticular or nodular opacities, most prominent in the lower lung fields. The CT findings of RB-ILD include ground-glass opacities, centrilobular nodules, and interstitial thickening. In addition to respiratory bronchiolitis, the radiologic differential diagnosis of RB-ILD includes nonspecific interstitial pneumonitis, desquamative interstitial pneumonia, and acute or subacute hypersensitivity pneumonitis (HP).
- References
- Park JS, Brown KK, Tuder RM, et al. Respiratory bronchiolitis-associated interstitial lung disease: radiologic features with clinical and pathologic correlation. J Comput Assist Tomogr 2002;26(1):13-20.
- Keywords
- Lung, Interstitial lung disease, RB-ILD, smoking related ILD,