Histologic and immunohistochemical comparison of intraductal tubular carcinoma, intraductal papillary-mucinous carcinoma, and ductal adenocarcinoma of the pancreas

Objective: To analyze the differences between intraductal tubular carcinoma (ITC) and intraductal papillary-mucinous carcinoma (IPMC), we performed light microscopic and immunohistochemical analysis of 4 cases of ITC, 6 cases of IPMC, and 9 cases of ductal adenocarcinoma of the pancreas. Methods and Results: Light microscopic examination showed no hyperplasia or adenoma around the carcinoma in ITC, and immunohistochemical analysis showed that the apical side of the cell membrane was positive for MUC-1 in almost all ITC cells. In contrast to ITC cells, all IPMC cells were negative for MUC-1 and ductal adenocarcinoma cells were strongly positive for MUC-1 in the cytoplasm and cell membrane. Immunohistochemical staining patterns of DUPAN-2 in ITC resembled those of MUC-1 in these cancers. ITC and IPMC cells were negative for carcinoembryonic antigen, but ductal adenocarcinoma cells were positive. There were no apparent differences in proliferative activity between ITC and IPMC, but ductal adenocarcinoma showed significantly greater activity than either ITC or IPMC. Conclusion: The PCNA-L. I of IPMC and ITC was lower and the cell atypia of them was more mild compared with those of ductal carcinoma, indicating that IPMC possess low-grade malignant potentials. However, we observed differences of growth patterns and mucous secretion between ITC and IPMC of the pancreas.