Jiaqi Shi has received her MD and PhD from the Hunan Medical University and Postdoctoral training from University of Arizona. She has completed her Pathology Residency and GasteroIntestinal Pathology Fellowship Training at University of Michigan (UM) in 2015. Currently, she is an Assistant Professor in the Department of Pathology at UM. Among her many awards, she has won the prestigious 2011 Benjamin Castleman Award from the United States and Canadian Academy of Pathology (USCAP). She has published more than 30 papers in reputed journals and has been serving as an Editorial Board Member of repute.


The differential diagnosis between an intraductal papillary mucinous neoplasm (IPMN) and intraductal tubulopapillary neoplasm (ITPN) can be difficult sometimes. IPMN is a mucinous cystic ductal neoplasm of the pancreas, whereas ITPN is mostly a solid intraductal neoplasm of the pancreas with no or minimum mucin. Therefore, gross examination and imaging is helpful to distinguish between these two entities. However, there is histologic overlap that could lead to erroneous diagnosis. Some of the histologic features in IPMN can resemble ITPN. Immunohistochemical stains of MUC5AC and MUC6 can also be helpful. Most of the IPMNs are positive for MUC5AC and negative for MUC6, with the exception of oncocytic type IPMN, while the opposite is true for ITPN. There are 4 subtypes of IPMN based on the epithelial cell lineage: Gastric, intestinal, pancreatobiliary and oncocytic types. Differentiating IPMN subtypes has clinical significance as they are associated with diverse prognosis. In the end, the most important question to address when evaluating IPMN or ITPN resection specimens is whether there is an invasive carcinoma component, because the prognosis is largely dependent on the answer of this question. A thorough examination of the lesion is desired to rule out an invasion.