Date Published: July 6, 2017
Publisher: Public Library of Science
Author(s): Xiaoye Wang, Lihua Wang, Weisheng Zhang, Hong Zhao, Feng Li, Fan Yang.
The purpose of our study was to assess the differentially diagnostic value of radiographic characteristics of pure ground glass nodules (GGNs) between minimally invasive adenocarcinoma and non-invasive neoplasm.
Sixty-seven pure GGNs (28 minimally invasive adenocarcinomas (MIA) and 39 pre-invasive lesions) were analyzed from June 2012 to June 2015. Pre-invasive lesions consisted of 15 atypical adenomatous hyperplasia (AAH) and 24 adenocarcinomas in situ (AIS). High-resolution computed tomography (HRCT) features and volume of MIA and pre-invasive lesions were assessed. Fisher exact test, independent sample t test, Mann-Whitney U test and receiver operating characteristic (ROC) curve analysis were performed.
Inter-observer agreement indexes for the diameter, mean HRCT attenuations and volume of pure GGNs were all high (ICC>0.75). Univariate analyses showed that lesion diameter, mean HRCT attenuation, and volume value differed significantly between two groups. Among HRCT findings, GGN shape as round or oval (F = 13.456, P = 0.002) and lesion borders as smooth or notched (F = 15.742, P = 0.001) frequently appeared in pre-invasive lesions in comparison with MIA. Type II and type III of the relationship between blood vessels and pure GGNs suggested higher possibility of malignancy than type I.
HRCT features of pure GGNs can help to differentiate MIA from non-invasive neoplasms.
Pure ground-glass nodules (GGN) are defined as focal nodular areas of increased lung attenuation on high-resolution computed tomography (HRCT), in which the pulmonary vessels and bronchia structures through the nodule can be observed . Most of persistent pure GGNs are diagnosed as focal interstitial fibrosis, adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), or even invasive adenocarcinoma [2, 3].Previous studies have classified the treatment of pure GGNs into two groups: one for appropriate treatment and the other for following-up .Which kind of pure GGNs should be resected or followed up? Can we predict the histologic subtypes and prognosis of pure GGNs? CT has been implemented on regular health check-up and HRCT enables these nodules to be investigated in more details, which are helpful for detecting malignant tumors at earlier stage. Most pure GGNs are indolent and often diagnosed as pre-invasive adenocarcinoma or MIA .
Pure GGNs detected using HRCT are commonly identified abnormalities with different pathological results. Currently, MIA and pre-invasive lesions as pure GGNs garner more attention in clinical practice.
HRCT characteristics of pure GGNs, including diameter, volume, shape, margin of lesions, mean HRCT attenuation, together with the relationship between pure GGNs and supplying blood vessels, can help to differentiate MIA from pre-invasive lesions to some extent.