Transient pulmonary eosinophilia incidentally found on low-dose computed tomography: Findings in 40 individuals

Purpose: To describe computed tomography (CT) findings of transient pulmonary eosinophilia (TPE) incidentally found on low-dose CT (LDCT) and to identify suggestive CT features helpful in initial diagnosis. Materials and Methods: We retrospectively reviewed LDCT scans in 40 individuals who met criteria for having TPE. There were 35 men and 5 women (age range, 32-62 years; mean, 48.5 +/- 9 years). Initial LDCT scans were assessed as either (a) nodules, further characterized as either solid, solid associated with a halo of ground-glass attenuation, or pure ground-glass lesions as well as by number, size, and location or (b) ill-defined foci of parenchymal consolidation. Results: A range of focal parenchymal abnormalities (n = 78) were identified-both single (48%) and multiple (52%). Most of these proved to be either solid nodules with discrete ground-glass halos (72%), or poorly defined solid nodules exhibiting a variety of differing morphologies (24%). Ill-defined foci of consolidation were noted in 3 cases (4%). The lesions were predominantly located in the lower lung zone (73%) with peripheral distribution (92%). Conclusions: Transient pulmonary cosinophilia most often manifests as solid nodules with associated ground-glass halos. Awareness of TPE should serve to limit the number of mistaken diagnoses of early lung cancer.