Multiple focal pure ground-glass opacities on high-resolution CT images: Clinical significance in patients with lung cancer.

OBJECTIVE

The purpose of this study was to evaluate the clinical significance of multiple focal pure ground-glass opacities (GGOs) on high-resolution CT images of patients with lung cancer.

MATERIALS AND METHODS

The cases of 23 patients with proven lung cancer and associated multiple focal pure GGOs on high-resolution CT images were retrospectively reviewed. The number, size, distribution, and morphologic characteristics of focal pure GGOs were evaluated. Serial changes in focal pure GGOs that were not surgically resected were analyzed at follow-up high-resolution CT.

RESULTS

The number of focal pure GGOs was 196 in total. The size of the opacities ranged from 2 to 30 mm in largest diameter. Lung cancer and focal pure GGOs were seen in the same lobe and/or in the other lobes. One hundred seventy-one of the lesions (87%) had a well-defined border or round shape. Histologic findings were obtained for 15 lesions representing 74 focal pure GGOs that were surgically resected: 11 atypical adenomatous hyperplasia lesions, three bronchioloalveolar carcinomas, and one lesion of focal fibrosis. In 110 of the cases of focal pure GGOs, all of which were followed up with HRCT for a median duration of 1,351 days, the size of 105 lesions (95%) did not change, the size of one decreased, and four lesions disappeared.

CONCLUSION

The size of most focal pure GGOs associated with lung cancer did not change during the follow-up period. Most of the small number of lesions histologically diagnosed were atypical adenomatous hyperplasia or bronchioloalveolar carcinoma. These data justify the therapeutic strategy of resecting the primary tumor without therapeutic intervention in the remaining focal pure GGOs.