Intraepithelial neoplasms of the pancreas.

Intraepithelial neoplasms of the pancreas have been recently described and relatively rare, but these lesions represent a distinct, however pathologically heterogeneous entity with shared clinical features. We analyzed the clinicopathologic and cytogenetic characteristics of eight patients with intraepithelial neoplasms. Based on our hypothesis that tumor ploidy pattern correlates with ploidy, synthetic (S) phase and proliferative fractions of each neoplasm by flow cytometry. Analysis of the nuclear DNA content of pancreatic intraepithelial neoplasms in this study supports our hypothesis. Each neoplasm demonstrated diploid stemline, with a low S-phase fraction. The diploid DNA pattern and the low proliferative activity are consistent with the nonaggressive behavior of the tumors and, in part, explain the favorable prognosis of intraepithelial neoplasms. Intraepithelial neoplasms of the pancreas constitute a rare, but surgically curable, localized disease with a good prognosis following radical resection. The most valuable tool in the diagnosis of these preinvasive lesions is ERCP combined with brush cytology. This study supports the potential value of flow cytometric DNA analysis in determining outcome, as the diploid DNA pattern and low S-phase fractions correlate with the nonaggressive biological behavior.