Honeycomb-like structures in sarcoidosis pathologically showing granulomas in walls of clustered bronchioles.

In the clinical setting, it is often difficult to judge whether honeycomb-like structures represent progression of fibrosis in pulmonary sarcoidosis or a complication by interstitial pneumonitis. This report described a valuable case in which pathology of video-assisted thoracoscopic surgery specimens collected from the lungs with honeycomb-like structures that were continuous with the dilated bronchioles on chest computed tomography (CT) showed granulomas in the membranous bronchiole walls, thereby demonstrating that the honeycomb-like structures were lung lesions of sarcoidosis. Pathological features of these structures on chest CT included cystic changes attributable to incorporation of peripheral alveoli into dilated bronchioles in lobules: these findings in lung sarcoidosis were different from those corresponding to honeycomb lung in idiopathic pulmonary fibrosis/usual interstitial pneumonia.

Honeycomb lung-like structures resulting from clustering of traction bronchiectasis distally in sarcoidosis.

Gene expression profiles of patients with progressive sarcoidosis, most of whom had evidence of fibrosis on imaging, have been reported to be similar to those of patients with inflammatory hypersensitivity pneumonitis, while expression profiles in progressive sarcoidosis did not resemble those of idiopathic pulmonary fibrosis. However, it is not known whether specific parenchymal features discerned on computed tomography (CT) imaging can predict development of fibrosis in pulmonary fibrosis. We herein describe a rare case of pulmonary sarcoidosis with honeycomb lung-like structures developing as a result of concentration of traction bronchiectasis distally, predominantly in both lower lung fields, which developed through shrinkage of consolidations comprising a "central-peripheral band" detected in a woman in her 60s, with non-caseating epithelioid granuloma.