Similar to submucosal pseudoinvasion of the mucosal glands, mucin spillage must be differentiated from invasive cancer.[9] Mucin is produced by tumor cells in mucinous adenocarcinoma or adenocarcinoma with mucinous differentiation, resulting in mucus retention and cystic dilatation of neoplastic glands. This evidence concerns the gene MUC5AC and colon mucinous adenocarcinoma.