Progressive Massive Fibrosis Mimicking Lung Cancer: Two Case Reports with Potentially Useful CT Features for Differential Diagnosis.

Progressive massive fibrosis (PMF) with atypical findings is often misdiagnosed as lung cancer. Atypical features of PMF have been described in some reports; however, these reports only introduced their cases with a short literature review. We report two cases of solitary PMFs with no underlying simple pneumoconiosis or rapid growth at atypical location that were mistaken for lung cancer. We also suggest the useful CT findings to aid in the differential diagnosis.