The Value Of Air Bronchogram In Differential Diagnosis Of Benign And Malignant Pulmonary Mixed Ground Glass Nodules And Prediction Of Lung Adenocarcinoma Invasiveness

ObjectivesTo explore the differential diagnosis value of air bronchial signs in the benign and malignant isolated pulmonary mixed ground-glass nodules(mGGN)and the predictive value of the invasion of lung adenocarcinoma.MethodsThe clinical data and CT image characteristics of 126 patients with pulmonary mixed ground glass nodules from The Affiliated Hospital of Qingdao University and The People’s Hospital of Qingdao Chengyang District from October 2018 to October 2021 were retrospectively analyzed.The selected cases were confirmed by biopsy or surgical pathology.According to the relationship between pulmonary nodules and bronchi,the air bronchogram can be divided into five types: type I,where the bronchi run and truncate within the solid component of mGGN.Type II,bronchi in mGGN solid components,with or without bronchial morphology distortion,dilation;Type III,bronchi in mGGN ground glass composition,accompanied by bronchial morphology distortion,expansion;Type IV,bronchi in mGGN ground glass composition normal running;V-shaped,the bronchi circled around the mGGN lesion without entering the lesion,with or without bronchial morphology distortion and dilation.The number of air bronchial signs of each type was recorded,and the data were statistically analyzed.The counting data were described by frequency and percentage.The difference was analyzed by χ2 or Fisher’s exact probability method,and P<0.05 was considered statistically significant.ResultsAmong 126 cases of lung mGGN,30 cases(23.81%)were benign and 96 cases(76.19%)were malignant.The malignant group included 5 cases(3.97%)of preinvasive lesions,14 cases(11.11%)of microinvasive adenocarcinoma,and 77 cases(61.11%)of invasive lung adenocarcinoma.The difference of air bronchograms between benign and malignant groups was statistically significant(χ2=10.619,P=0.031).Air bronchial signs I,II and III were more common in malignant tumors,while air bronchial signs IV and V were more common in benign lesions.There was significant difference in air bronchogram sign among the groups of mGGN lung adenocarcinoma(χ2=39.713,P<0.001).Type I,II and III were more common in invasive lung adenocarcinoma group,type IV in micro-invasive lung adenocarcinoma group,and type IV and V in pre-invasive lung adenocarcinoma group.The difference of air bronchial sign among different pathological subtypes of invasive lung adenocarcinoma was statistically significant(χ2=31.436,P<0.001),the mural lung adenocarcinoma was more common with air bronchogram type III,acinar or papillary lung adenocarcinoma was more common with air bronchogram type II,solid or micropapillary lung adenocarcinoma was more common with air bronchogram type I.ConclusionsDetailed analysis of air bronchogram typing is of great significance for the qualitative diagnosis of lung mGGN,and air bronchogram sign can predict the invasiveness of lung adenocarcinoma with mGGN.