Retrospective analysis of clinicopathological features of solid pseudopapillary neoplasm of the pancreas.

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare neoplasm that accounts for 2-3% of all primary pancreatic neoplasms. This study aimed to characterize clinicopathological features associated with SPNs and to retrospectively evaluate the relationship of these features with predictive parameters associated with aggressive behavior. We reviewed 16 cases of SPN of the pancreas that had been diagnosed between 2005 and 2014 at our pathology department. A total of 16 cases, 15 female and one male, were evaluated in this study. The patient age ranged from 13 years to 63 years with a median of 35.70 years. The mean tumor diameter ranged from 2 cm to 18 cm with a mean diameter of 5.90 cm. We identified a significant association between the presence of clear cells and perineural invasion (p=0.019), which was considered to be a predictive factor for aggressive behavior. Other features (i.e., localization, nuclear grooves, central hyalinization, myxoid stroma, eosinophilic bodies, foamy histiocyte aggregates, multinucleated cells, and calcification) were not significantly associated with predictive factors for aggressive behavior. One patient died as a result of a pancreatic fistula that developed as a postoperative complication. The remaining 15 patients are alive and have not demonstrated any signs of recurrence or metastasis. The current study suggested that the presence of clear cells might serve as a possible prognostic indicator of perineural invasion, which is a predictive parameter associated with aggressive behavior in SPN.