Focal area of ground-glass opacity and ground-glass opacity predominance on thin-section CT: discrimination between neoplastic and non-neoplastic lesions.

AIM To reveal differences in thin-section computed tomography (CT) findings between lung neoplastic lesions and non-neoplastic lesions, which showed a focal area of ground-glass opacity or ground-glass opacity predominance. MATERIALS AND METHODS A total of 82 focal areas of ground-glass opacity and ground-glass opacity predominance, consisting of 38 neoplastic and 44 non-neoplastic lesions, were assessed retrospectively regarding their thin-section CT findings. RESULTS The frequency of wholly well-defined margin (p=0.001), spiculation (p=0.019), pleural indentation (p=0.016), air bronchograms (p=0.027), air-containing space (p=0.004) was significantly higher in neoplastic lesions than in non-neoplastic lesions. Thirty-four of 38 (89%) neoplastic lesions were well-defined in more than 50% of the circumference, of which nine had an air-containing space other than air bronchogram, whereas only one non-neoplastic lesion had these features. CONCLUSION A focal area of ground-glass opacity or ground-glass opacity predominance with a well-defined margin and air-containing space is more likely to be a neoplasm.