DNA flow cytometry and clinicopathology of intraepithelial neoplasms of the pancreas

Introduction: The purpose of this study was to analyze intraepithelial neoplasms of the pancreas, with particular attention to presentation, diagnostic workup, surgery, histopathology, and cytogenetics. We hypothesized that tumor ploidy pattern correlated with biological behavior, malignant potential and prognosis.

Methods: The records of eight patients with pancreatic intraepithelial neoplasms were retrospectively reviewed. Nuclear DNA-content, ploidy, synthetic (S) phase and proliferative fractions of each neoplasm were measured by flow cytometry.

Results: We report 4 cases of pancreatic ductal carcinomas in situ (DCIS), 2 cases of mucinous ductal ectasia (MDE) and 2 cases of atypical ductal hyperplasia (ADH). Presenting symptoms included abdominal pain of greater than one month's duration (n=6), unplanned weight-loss (n=4), and jaundice (n=2). Seven patients were previously diagnosed with pancreatitis. Preoperative work-up included ultrasonography, computed tomography and endoscopic retrograde cholangiopancreatography. Serum chemistries, tumor-associated antigens CEA and CA-19 were within normal limits. All patients had abnormal ERCP studies with ductal filling defects or dilation. Five patients had identifiable masses on abdominal CT. All of the patients had undergone radical resection of the pancreas. All tumors demonstrated diploid stemline with a mean S-phase (proliferative) fraction of 3.7% and a mean DNA index of 0.96. All patients survived and tumor-free through five years follow up.

Conclusion: Intraepithelial neoplasms of the pancreas are rare but surgically curable, localized disease. These preinvasive lesions are diagnosed by ERCP with brush cytology, and cured by radical resection. The diploid DNA pattern and low S-phase fractions correlate with the nonaggressive biological behaviour.