Objective To investigate the high resolution CT (HRCT) imaging features of pulmonary ground-glass nodules (GGN) and their correlation with immunohistochemical (IHC) examination indexes and evaluate their clinical value.

Methods The clinical data of 144 patients with pulmonary GGN diagnosed by surgery and histopathological examination in Shunde Hospital of Southern Medical University (the First People's Hospital of Shunde) from January 2019 to May 2020 were retrospectively analyzed, including 46 males and 98 females, aged 28–80 (51.9±11.9) years old. All patients underwent surgery and IHC. Based on the new classification of lung tumor tissue by the World Health Organization in 2021, 144 patients with pulmonary GGN were divided into three groups: pre-invasive lesion (PI), microinvasive adenocarcinoma (MIA), and invasive adenocarcinoma (IA). The differences in HRCT imaging features of the three groups of pulmonary GGN patients and their correlation with IHC examination indexes were compared. The image features were compared between groups by analysis of variance or χ² test. Univariate and multivariate Logistic regression models were used to analyze the influencing factors and establish a prediction model. In addition, the receiver operator characteristic curves were drawn to obtain the best diagnostic cut-off value. χ² test was used to analyze the correlation between HRCT image features and the expression level of IHC examination indexes.

Results Results of univariate Logistic regression analysis showed that the GGN diameter, lobulation, spiculation, pleural traction sign, tumor-lung boundary, microvascular perforation sign and air bronchial sign were significantly different among the three groups (F=8.952–82.901, all P<0.05). Meanwhile, the results of multivariate Logistic regression analysis showed that the GGN diameter was an independent risk factor for the evaluation of pulmonary GGN infiltration. It tended to PI when the GGN diameter was <6 mm, MIA when the GGN diameter was 6 mm≤GGN diameter≤10 mm, and IA when the GGN diameter was >10 mm. Results of IHC showed that vascular endothelial growth factor (VEGF), p53, and proliferating cell nuclear antigen (Ki-67) had high predictive values in predicting the degree of pulmonary GGN infiltration, with area under curves of 0.829, 0.773, and 0.760, respectively. Moreover, results of correlation analysis showed that patients with GGN diameter of >10 mm, lobulation, spiculation, and pleural traction sign as well as tumor-lung boundary were correlated with the expression of VEGF, p53, Ki-67 (χ²=13.582–41.351, all P<0.05). Microvascular perforation sign was correlated with the high expression level of Ki-67, and the low expression level of VEGF and p53 (χ²=15.111, 15.644, 16.121; all P<0.05）.

Conclusions GGN diameter was an independent risk factor for the evaluation of pulmonary GGN infiltration and has good diagnostic efficacy. The HRCT imaging features of the pulmonary GGN were correlated with the expression levels of Ki-67, p53, and VEGF. The comprehensive analysis of HRCT imaging features and IHC examination indexes of pulmonary GGN can evaluate the histopathological classification, proliferative activity, and infiltration of tumor cells, as well as provide valuable references for clinical management and selection of appropriate treatment for patients with pulmonary GGN.