Distinctive clinicopathological features of adenocarcinoma in situ and minimally invasive adenocarcinoma of the lung: A retrospective study

•WHO defined AIS and MIA as early phases of lung adenocarcinoma in 2015.•Patients with MIA, compared to those with AIS are more likely to be male.•Ki-67 labeling index for cell proliferative activity distinguishes MIAs from AIS.•MIAs have more EGFR mutations, with a higher exon 19 to 21 mutation ratio than AIS.•Distinguishing AIS from MIA is apt despite the same good outcomes after resection.