Compared with non-mucinous lung adenocarcinoma (LUAD), mucinous LUAD are rare (3%-10% of all LUAD) and include invasive mucinous adenocarcinoma (IMA) and the exceedingly rare colloid adenocarcinoma.1 IMA differ from invasive non-mucinous LUAD by histomorphology, clinical course and genomic characteristics.2,3 Histologically, IMA feature malignant goblet or columnar cells with abundant intracytoplasmic mucin.1 Previous studies have shown that IMA are enriched for KRAS mutations, especially G12D and G12V, and targetable fusions like NRG1, ALK and ERBB2 alterations.