Radiological imaging and pathological findings of small lung adenocarcinoma: a narrative review

The eighth edition of the Lung Cancer Handling Regulations defines the pathological findings of “invasion” in the pathological diagnosis of lung adenocarcinoma and terms it as adenocarcinoma in situ/minimally invasive carcinoma. In addition, the invasion diameter (tumor diameter excluding the lepidic growth region) was adopted as the pT factor, and the classification further reflected prognosis (degree of invasion/progression). Meanwhile, computed tomography imaging-based classification, where the consolidation (nodule) diameter excluding the ground glass shadow area was defined as cT, and the classification reflected the pathological invasion diameter. It is clear that the revision of the eighth edition has reduced discrepancies in the pathological findings of lung adenocarcinoma in CT imaging and assessment of the degree of invasion and progression. At the same time, the 8th edition is not yet accurate enough. Therefore, we will discuss imaging techniques to better predict the extent of adenocarcinoma invasion and progression, based on our own findings and the literature.