Circulating Epithelial Cells in Intraductal Papillary Mucinous Neoplasms and Cystic Pancreatic Lesions

Objectives Circulating epithelial cells (CECs) are identified in the blood of patients with intraductal papillary mucinous neoplasms (IPMNs) despite the absence of malignancy. We assessed the blood of patients undergoing resection for IPMN or other benign pancreatic lesions for CECs. Methods Peripheral blood was collected from 26 patients prior to pancreatic resection and filtered by the ISET (Isolation by Size of Epithelial Tumor Cells) method. Circulating epithelial cells were identified with antibodies to cytokeratin and Pdx1 (pancreas and duodenal homeobox protein 1), a pancreas marker. Results Nineteen patients underwent resection of an IPMN without associated malignancy. Eleven patients (58%) had cytokeratin-positive CECs. Circulating epithelial cells were significantly more likely to be found in patients with IPMNs with high-grade dysplasia (P = 0.04). In addition, 10 of the 11 patients with cytokeratin-positive CECs also had separate populations of cytokeratin-positive, Pdx1-positive CECs, suggesting a pancreatic source. Dual-staining CECs were more frequently found in patients with high-grade dysplasia (P = 0.04). Patients with IPMNs were significantly more likely to have pan-cytokeratin CECs in the blood compared with those without IPMNs (P = 0.01). Conclusions Circulating epithelial cells staining with potential pancreas-specific markers have been found in patients with IPMNs, even without malignancy. Circulating epithelial cells may help to differentiate patients with high-grade IPMN from lower grades of dysplasia and other pancreatic cysts.