In 2011,the International Association for the Study of Lung Cancer(IASLC),American Thoracic Society(ATS)and European Respiratory Society(ERS)simultaneously defined micropapillary pattern(MPP)-based lung adenocarcinoma as an independent pathological type:micropapillary-predominant adenocarcinoma(MPA).Its histological and clinical specificities have attracted broad attention from researchers.Lung adenocarcinoma with a micropapillary pattern(MPPAC)often shows biological behaviors indicative of poor prognosis,including strong invasion,high metastasis rate and easy recurrence after surgical treatment.At present,the clinical diagnosis of MPPAC depends on postoperative pathological examination,but systematic studies on its pathological heterogeneity,molecular biological characteristics,clinical features and prognosis remains scarce.This review aims to focus on the research progress of the pathological and clinical features of MPPAC.