Mucinous adenocarcinoma (MAC) and SRCC are less commonly observed subtypes, with MAC accounting for 10% of cases, and SRCC accounting for 1% of cases.8,9,21–23 SRCC is defined by the presence of >50% of tumour cells with intracytoplasmic mucin, whereas MAC is defined as carcinoma with >50% of the tumour volume showing extracellular mucin.24 Due to the rarity of this subtype and the difficulties associated with characterising it molecularly, genomic alteration data in SRCC are scarce. This evidence concerns the gene MUC5AC and colon mucinous adenocarcinoma.