The cyst cell lining was composed of mature, keratinized, or non-keratinized stratified squamous epithelium and focally mucin-producing ciliated stratified epithelium; however, there were no findings of gastrointestinal mucosal epithelium in the entire cyst and there was no smooth muscle outer layer in the cystic wall, except for an attached portion of the cecal wall. Here, MUC5AC is linked to cyst.