Localized pure ground-glass opacity on high-resolution CT: Histologic characteristics

Purpose: The aim of this study is to assess the histologic characteristics in cases of localized pure ground-glass opacity (LPGGO) that do not exhibit consolidation on high-resolution CT (HRCT) images. Method: Twenty surgically resected lesions from 20 consecutive cases were retrospectively investigated. Each of the 20 lesions had exhibited LPGGO on HRCT images. The HRCT images and histopathologic findings were examined for correlations. Results: The areas of LPGGO had a maximum diameter of 2.0-24 mm, on the HRCT images. Histopathology of the LPGGO lesions resulted in diagnosis of fibrosis (n = 3; 15%), atypical adenomatous hyperplasia (n = 5; 25%), bronchioloalveolar carcinoma (n = 10; 50%), and adenocarcinoma with stromal invasion (n = 2; 10%) Nonaerogenous components corresponding to solid components without normal alveolar septal destruction were pathologically observed in 15 of the 20 lesions. The diameter of the nonaerogenous components varied between 0.2 and 2.0 mm. Conclusion: Because 10% of LPGGO lesions include invasive disease, patients with LPGGO should undergo pathologic examination for confirmation.