Intraductal Papillary Mucinous Neoplasm: Is It Safe to Watch and Wait?

Abstract

Intraductal Papillary Mucinous Neoplasm: Is It Safe to Watch and Wait? Mohammad Al-Haddad, Hugo Bonatti, Surakit Pungpapong, Kyung W. Noh, Seth A. Gross, Massimo Raimondo, Timothy A. Woodward, Michael B. Wallace Introduction: Intraductal papillary mucinous neoplasms of the pancreas (IPMN) are increasingly recognized in clinical practice. They represent a unique clinicopathologic entity that is characterized by mucin production, cystic dilation of the pancreatic ducts, and intraductal papillary growth. Published literature suggests that up to 45% of IPMN are malignant and should be resected however these data are based on larger, primarily symptomatic lesions. The risk of malignancy and need for surgical resection in smaller, lower risk lesions is not known. Aim: To identify predictors of a benign natural history in patients with IPMN. Methods: Patients with cystic lesions of the pancreas suspicious for IPMN were evaluated for known and potential clinical predictors of malignancy. Surgery was advised for those with a ‘‘high risk’’ features (mass, mural nodule, malignant cytology or CEA O 200 ng/ml on EUS-fine needle aspiration or pancreatic symptoms). Other patients were managed with serial imaging (CT or MRI) and clinical follow up. Potential predictors were compared to a gold standard of surgical pathology or long term clinical follow up without progression. Results: Sixty five patients with IPMN were included. Fortyfour patients IPMN were followed conservatively and were compared to 21 patients who underwent surgical resection based on high-risk features. Cancer or dysplasia was found in 9/21 (43%) of resected patients. None of the conservative group developed cancer during a median follow up of 7 months (2-52 months). The presence of a mass on EUS, main duct involvement and younger age were all predictors of malignancy (Table 1). Although there was an observed difference between the 2 groups in regards to presence of symptoms and mural nodules, it did not reach statistical significance. None of the other factors were found to be significant in predicting malignancy. Conclusions: 1Conservative management of IPMN with no features of malignancy is probably safe 2. This study confirms the previously described predictors for development of malignancy in IPMN including main pancreatic duct involvement and presence of masses. We found an unexpected inverse association with age that requires further studies to evaluate.