serous cystadenoma pancreas treatmentcystadenoma pancreasoligocystic serous cystadenomaserous pancreatic cystserous ovarian cancerserous carcinoma of the uterusserous uterine cancer prognosispancreatic ductal adenocarcinomametastatic pancreatic carcinomapancreatic neuroendocrine cancermetastatic pancreatic cancermetastasized pancreatic cancer