Atypical HRCT manifestations of pulmonary sarcoidosis
PURPOSE Computed tomographic (CT) findings of pulmonary sarcoidosis were correlated with histopathologic features determined at open lung biopsy or autopsy. MATERIALS AND METHODS Eight patients (six men and two women, aged 22-65 years) with pulmonary sarcoidosis diagnosed at histologic examination were studied at CT with a high-spatial-frequency algorithm. RESULTS The most frequent CT features were irregularly thickened bronchovascular bundles (seven of eight cases [88%]) and small nodules along vessels (four cases [50%]). These features corresponded to granulomas formed in the connective tissue sheath around the pulmonary vessels and airways. This characteristic CT appearance was the result of the bronchovascular distribution of sarcoid granulomas. Granulomas adjacent to the visceral pleura or formed in the pleura in four patients were correlated with pleural or subpleural involvement. Ground-glass attenuation, present in six patients (75%), did not correlate with alveolitis in any patient. CONCLUSION CT is a valuable technique with which to visualize the characteristic location of sarcoid granulomas in the pulmonary parenchyma.