The morphological changes of bronchovascular bundles within subsolid nodules on HRCT correlate with the new IASLC classification of adenocarcinoma

Aim To observe the morphological changes of bronchovascular bundles within subsolid nodules on high-resolution (HR) computed tomography (CT) and analyse the correlation with the new adenocarcinoma classification. Materials and methods Two hundred and sixteen lesions (absent consolidation on mediastinal window) were reviewed retrospectively. CT features including dimensions, contour, morphological changes of the blood vessels, and bronchi/bronchioles, vacuole signs, and their correlation with histopathology were evaluated. Results Excluding nine non-cancerous lesions, 34 pre-invasive lesions (PILs) including 15 atypical adenomatous hyperplasias (AAHs) and 19 adenocarcinomas in situ (AISs), 21 minimally invasive adenocarcinomas (MIAs), and 152 invasive adenocarcinomas (IACs) were analysed. Lepidic, acinar, and papillary patterns were identified in this cohort of adenocarcinomas. IACs were grouped into three types: type I (lepidic pattern ≥80%, n= 47), type II (lepidic pattern ≥50%, n= 67), and type III (lepidic pattern n= 38). The contour of lesions, and morphological changes in vessels and bronchi/bronchioles significantly correlated with the classification of PIL, MIA, and IACs ( p= 0.000, p= 0.000, and p= 0.017, respectively). In IACs, the prevalence of vascular abnormalities on HRCT significantly correlated with ( p= 0.000) the proportion of non-lepidic pattern (23.40% in type I, 58.21% in type II, and 76.32% in type III); the prevalence of bronchial/bronchiolar abnormalities was higher ( p= 0.008) in type II/III (20.95%) compared with type I (6.38%). Conclusions The morphological changes of vessels and bronchi/bronchioles within the subsolid nodules on HRCT help to differentiate IAC from PIL and MIA, and are more common in non-lepidic predominant adenocarcinomas.