Pancreatic neuroma-like lesions after upper abdominal surgery: a clinicopathological postmortem study

To elucidate poorly understood pancreatic neural changes after upper abdominal surgery (UAS), we histologically examined 57 postmortem pancreases after gastrectomy, esophagectomy, and esophageal transection, and also investigated each clinical manifestation. Six pancreases (10.5%) had unique histopathological lesions composed of prominently thickened and/or proliferated neural fascicles. They focally or multifocally involved the pancreatic lobules and/or interlobular septa and mimicked traumatic neuroma. Three of the six lesions were accompanied by moderate to severe chronic pancreatitis/pancreatic fibrosis. All six patients were asymptomatic, although only one exhibited a low-echoic pancreatic mass. There were no statistically significant associations between the pancreatic neural lesions and the patients' sex, age, the time interval between the surgery and the patients' death, impaired glucose tolerance, the presence of hyalinized pancreatic islets, or the presence of moderate to severe chronic pancreatitis/pancreatic fibrosis. No similar prominent neural lesions were identified in an additional 57 age- and sex-matched control pancreases. We concluded that these prominent neural lesions were pancreatic neuroma-like lesions following UAS. This study failed to demonstrate the distinct pathogenesis of the neuroma-like lesions and further investigation may be needed. However, this report is the first to delineate that asymptomatic neuroma-like lesions can occur following UAS. Consideration of this possible development would be useful for accurate follow-up of patients who undergo UAS, although its occurrence may be infrequent.