Based mainly on the number of tumor cells and morphology of tumor nests, atypia, mitotic figures, and the form of surrounding invasion, PMP is divided into four different prognostic groups: acellular mucin, low-grade PMP (LG-PMP), high-grade PMP (HG-PMP) and HG-PMP with signet ring cells [4]. Here, MUC5AC is linked to neoplasm.