MUC5AC and carcinoma: 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.