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

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.

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.

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%).

Transient pulmonary eosinophilia 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.