Simple pulmonary eosinophilia found on follow-up computed tomography of oncologic patients.

OBJECTIVES

To investigate the prevalence of simple pulmonary eosinophilia (SPE) and validate CT findings of SPE found on follow-up CT of oncologic patients.

METHODS

We retrospectively reviewed 6977 cases of oncologic patients who underwent chest CT. A total of 66 individuals who met criteria for having SPE were identified. CT scans were fully re-assessed by consensus of 2 radiologists in terms of characteristics of pulmonary lesions.

RESULTS

The prevalence of SPE was 0.95%. A total of 193 lesions were identified and most of the lesions showed part-solid pattern (69.9%), round to ovoid contour (46.1%), ill-defined margin (90.2%), or partial halo appearance (74.8%). In addition, almost half of the lesions showed the vascular contact (49%). SPE appeared as either solitary (42.4%) or multiple lesions (57.6%). The majority of lesions were located in the periphery (76.2%), and lower lung zonal (67.4%) predominance was found.

CONCLUSIONS

The frequency of SPE in oncologic patients with CT findings of GGO, part-solid lesion was high (17.5%). Therefore, when key features of CT findings suggesting SPE (part-solid nodule; ill-defined margin; peripheral distribution; and lower lung zone predominance) are newly discovered on follow-up chest CT in oncologic patients, it would be useful to correlate with blood test and do short-term follow-up in order to avoid unnecessary invasive procedure.