Since Posen et al. reported the first case of an UC with OGCs of the pancreas associated with a mucus-secreting cystadenocarcinoma in 1981 [2], there have been 11 additional cases of UC with OGCs of the pancreas originating in mucinous cystic neoplasms (MCN) and indeterminate mucin-producing cystic neoplasm reported in the English language literature [2-12]. Here, MUC5AC is linked to cystadenocarcinoma.