Outcome of Invasive and Noninvasive Intraductal Papillary-Mucinous Neoplasms of the Pancreas (IPMN): A 10-year Experience

BACKGROUND: Intraductal papillary-mucinous neoplasms (IPMN) were officially introduced into the TNM classification in 1996. Based on a two-center database, we reevaluated histopathological findings, clinicopathological pattern, predictive markers for malignancy, and outcome. METHODS: Between 1996 and 2006, a total of 1424 pancreatic resections were performed in the University Hospitals Dresden and Mannheim. Pathologists of both institutions reviewed the IPMN diagnoses and other with cystic or solid tumor diagnoses. All possible markers, such as diabetes, jaundice, etc., were analyzed for prediction of malignancy. We performed a survival analysis based on the morphologic classification to determine the prognosis of IPMN. RESULTS: There were 43 patients of primarily diagnosed IPMN along with 1174 patients with diagnoses, such as ductal adenocarcinoma. In 207 patients, the diagnoses revealed other cystic or small solid tumors. A histopathological review of the latter patients revealed 54 IPMNs, resulting in a total of 97 IPMN patients (29 noninvasive, 68 invasive). All IPMN patients had a median survival of 36 months. Recurrence occurred more frequently in invasive IPMN. Predictive markers of malignancy were pain, preoperative weight loss, jaundice, and elevated CA 19.9. The strongest independent prognostic factor was invasive growth. The survival analysis revealed excellent prognosis for noninvasive IPMN. CONCLUSIONS: Since the introduction of IPMN in 1996, even specialized centers have had to deal with a learning curve. By reevaluating all cystic or small solid tumors, centers can improve and their patients' treatment can be optimized. Because the preoperative diagnostic methods are not sensitive enough to differentiate between benign and malignant lesions, surgery is advocated for all main duct IPMN, because they have a high malignant potential. For branch duct IPMN, surgery is advocated if the lesion is symptomatic, >3 cm, or has enlarged nodules.