Yajima et al reported that all malignant tumors of the appendix were expressed with MUC-2, whereas ovarian cancer only expressed with MUC-1, rather than with MUC-2.[20] Primary SRCC-A also needs to be differentiated from goblet cell adenocarcinoma, which has a unique growth pattern and is located in the submucosa. Here, MUC2 is linked to ovarian carcinoma.