Cystic pancreatic schwannoma in a 46-year-old man. 
Pancreatic schwannomas are a rare benign mesenchymal neoplasm of the pancreas.  They are thought to arise from the epineurium of either autonomic sympathetic or parasympathetic fibers, which course through the pancreas with the vagus nerve.  Large pancreatic schwannomas often undergo cystic change, which causes them to be often confused with other more common cystic pancreatic neoplasms preoperatively.  The radiological, histologic, and immunohistochemical findings of pancreatic schwannomas are consistent with those of neoplasms found in other sites.  Treatment is by surgical resection, and the prognosis is excellent.  The awareness and, to some extent, knowledge of less common tumors in the pancreas are needed to achieve the diagnosis.  We discuss the clinical and pathologic features and differential diagnosis of cystic pancreatic tumors.