Kim M, et al. - Researchers explored the prognostic factors of acinar/papillary lung adenocarcinomas and tried to describe the so-called “intermediate grade” group of lung adenocarcinoma. Included in this study were 301 cases with stage I-III lung adenocarcinoma; acinar/papillary type were 193 (64.1%). Intermediate survival was displayed by acinar/papillary types vs lepidic and micropapillary/solid types in survival analysis of the whole cohort. Poor recurrence-free survival and overall survival were reported in relation to stage, age, lymphovascular invasion, spread through air spaces, presence of micropapillary or solid pattern, and programmed death-ligand 1 (PD-L1) positivity, in univariate survival analysis for acinar/papillary types. In the acinar/papillary cohort, the independent poor prognostic factor of recurrence-free survival was spread through air spaces and of overall survival was PD-L1 expression, as revealed in multivariate analysis. Experts concluded the possible usefulness of assessment of the spread through air spaces and PD-L1 expression for the stratification of patients with acinar/papillary lung adenocarcinomas with respect to prognosis.