Characterization of scattered neuroendocrine cells in ductal carcinoma of the pancreas.

INTRODUCTION

Scattered neuroendocrine cells, identified by chromogranin A (CGA) immunoreactivity, have been observed in pancreatic ductal carcinomas, accounting for <1% of the entire tumor cell population.

AIMS AND METHODOLOGY

To determine the characteristics of scattered CGA-positive cells, the differentiation markers for the cells of epithelial origin (cytokeratin [CK] 19) and of endocrine origin (CGA) were evaluated by immunohistochemistry and double immunofluorescent staining.

RESULTS

Some of these CGA-positive cells scattered amid malignant cells also express CK19, suggesting that they are neuroendocrine-differentiated carcinoma cells. However, scattered CGA-positive cells, mostly located at the basal and/or outer portions of malignant ducts, did not express CK19, indicating that these cells are probably entrapped endocrine cells. Examination of the lymph node metastases for CGA in 19 patients showed no staining with CGA, suggesting that neuroendocrine-differentiated tumor cells have a different behavior.

CONCLUSION

The current study did not show any clinical significance of these scattered neuroendocrine cells.