Neuroendocrine differentiation in pancreatic duct carcinoma special emphasis on duct-endocrine cell carcinoma of the pancreas.

To evaluate the significance of neuroendocrine differentiation in duct carcinoma of the pancreas, we investigated 79 pancreatic carcinomas, applying histochemistry and immunohistochemistry (chromogranin A, Leu-7, synaptophysin and neuron-specific enolase (NSE), and correlated the morphologic differentiation pattern with clinicopathological characteristics. There were two types of neuroendocrine differentiation: scattered (n = 23) and diffuse (n = 3). The scattered type of pancreatic duct carcinoma contained scattered endocrine cells amounting to less than 10% of the neoplastic cells and was seen more frequently in well-differentiated carcinomas. There was no characteristic clinical feature found in the scattered type when compared with the tumors devoid of endocrine cells (n = 53). In contrast, the diffuse type showed diffuse immunostaining with NSE and synaptophysin in tumor cells and dense core granules ultrastructurally. These tumors showed a greater hypervascularity in angiography (p < 0.01) and the patients had relatively longer survival (33.3 months, p < 0.05) than unresectable cases of other histological types of pancreatic cancer. Two types of neuroendocrine differentiation (scattered and diffuse) existed in pancreatic ductal carcinoma. The diffuse type (Duct-Endocrine Cell Carcinoma of the Pancreas) showed synchronous duct and endocrine differentiation and particular clinical features.