Table 1. The revised classification of lung adenocarcinoma (6).

(I) Preinvasive lesions

(i) Adenocarcinoma in situ (AIS) —mucinous, nonmucinous, or mixed

(ii) Atypical adenomatous hyperplasia (AAH)

(II) Minimally invasive lesions

(i) Minimally invasive adenocarcinomas (MIA) —mucinous, nonmucinous, or mixed

(III) Invasive adenocarcinoma

(i) Acinar predominant

(ii) Papillary predominant

(iii) Micropapillary predominant

(iv) Solid predominant with mucin production

(v) Lepidic predominant adenocarcinoma (LPA)

(IV) Variants of invasive adenocarcinoma

(i) Invasive mucinous adenocarcinoma

(ii) Colloid, fetal, and enteric

IASLC/ATS/ERS classification of lung adenocarcinoma in resection specimens; IASLC/ATS/ERS, the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society.