Table 1. 2011 International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification of lung adenocarcinoma in research specimens
Pre-invasive lesions
    Atypical adenomatous hyperplasia
    Adenocarcinoma in situ (≤3 cm formerly solitary BAC)
    Non-mucinous
    Mucinous
    Mixed mucinous/nonmucinous
Minimally invasive adenocarcinoma (≤3 cm lepidic predominant tumour with ≤5 mm invasion)
    Nonmucinous
    Mucinous
    Mixed mucinous/nonmucinous
Invasive adenocarcinoma
    Lepidic predominant (formerly nonmucinous BAC pattern with >5 mm invasion)
    Acinar predominant
    Papillary predominant
    Micropapillary predominant
    Solid predominant with mucin production
Variants of invasive adenocarcinoma
    Invasive mucinous adenocarcinoma (including formerly mucinous BAC)
    Colloid
    Fetal (low and high grade)
    Enteric

  • BAC: bronchoalveolar carcinoma. Reproduced from [11] with permission from the publisher.