IPMN : Adenocarcinoma
Intraductal papillary mucinous neoplasm (IPMN) of pancreas with adenocarcinoma: Invasive adenocarcinoma is seen in about 50%-64% of main duct-IPMNs and 18% of branch duct-IPMNs and can be colloid type or tubular (ductal) adenocarcinoma. Colloid carcinoma consists of strips of neoplastic cells within pools of stromal mucin. It usually arises in association with intestinal-type IPMN. The other morphologic pattern is tubular (ductal) adenocarcinoma, resembling conventional pancreatic ductal adenocarcinoma, seen in association with pancreatobiliary-type or gastric-type of IPMN. When invasive carcinoma is not contiguous with the focus of IPMN, it is designated IPMN with concomitant invasive carcinoma. The IPMN in such cases is usually branch duct type and the invasive component is tubular adenocarcinoma.