With the widespread use and advances in radiographic imaging, Intraductal Papillary Mucinous Neoplasms (IPMNs) of the pancreas are identified with increasing frequency. Although many studies have addressed its biology and treatment, true understanding of its natural history continues to elude us. Its malignant potential places careproviders in a clinical dilemma of balancing the morbidity of pancreatectomy against the risk of malignant transformation while under continuous surveillance. Recently, there have been conflicting data published in the literature, generating more uncertainty in the field. In this article, we critically analyze the contrasting consensus guidelines from the International Association of Pancreatology and the American Gastroenterology Association, and address lingering questions and controversies. We also synthesize newly published data in the context of current standard of care, and provide a comprehensive review and recommendations for the clinical diagnosis, treatment, and follow-up strategy in the management of patients with Intraductal Papillary Mucinous Neoplasms.

Management of cystic lesions of the pancreas (CLP) is controversial. In this study, we sought to evaluate national changes in the resection of CLP over time, to better understand the impact of evolving guidelines on CLP management.

We used Medicare data to examine CLP resection among patients undergoing pancreatic resection between 2001 and 2012. Patients with a diagnosis of CLP were identified and compared to patients with non-CLP indications. We then examined changes over time in patient and hospital characteristics and outcomes among patients with a CLP diagnosis.

We identified 56,419 Medicare patients undergoing pancreatic resection, of which 2129 had a CLP diagnosis. The annual number of CLP resections, and proportion of all resections performed for CLP increased significantly during the period, from 2.1% (65/3072) resections in 2001, to 4.5% (286/6348) in 2012 (p < 0.001). The proportion of CLP resections with a malignant diagnosis did not change (15.5% in 2001-2003 vs. 13.1% in 2010-2012, p = 0.4). Overall rates of 30-day mortality decreased significantly during the period (9.6% in 2001-2003 vs. 5.5% in 2010-2012, p < 0.001).

CLP resections were performed with increasing frequency in Medicare patients between 2001 and 2012, but this did not correspond to increased diagnosis of malignancy. Additional research is needed to understand the influence of recent guidelines on management of CLP.

Intraductal papillary mucinous neoplasms (IPMN) are being diagnosed with increasing frequency, necessitating an algorithm to help stratify patients into low- and high-risk groups, for follow-up versus more invasive evaluation. New evidence concerning their natural history and overall risk of malignancy has emerged since the 2006 International Association of Pancreatology consensus guidelines, prompting an update in 2012, that distinguishes radiologic 'worrisome features' from 'high-risk stigmata'. The aim of this article is to illustrate, with case examples, the variable imaging patterns of IPMN and how their radiologic features, such as cyst size and mural nodules, are interpreted in the context of the new 2012 guidelines. The 2012 and 2006 guidelines will be compared and discussed with reference to additional studies that have since been published. Despite these guidelines, lingering uncertainty remains about the natural history of IPMN, a source of unease to both radiologists and referring clinicians alike, mandating further refinement of clinical and radiologic parameters predictive of malignancy. Emerging data regarding the risk of extrapancreatic malignancy, as well as synchronous or metachronous pancreatic ductal adenocarcinoma remote in location from a branch duct IPMN are also reviewed. With the expanding research and evolving understanding of this clinicopathologic entity across the globe, radiologists will continue to play an important role in the management of patients with IPMN.

International consensus guidelines to guide management of intraductal papillary mucinous neoplasms (IPMN) were revised in Fukuoka and published in 2012. However, despite widespread acceptance of the Fukuoka Consensus Guidelines (FCG), the utility of these guidelines have not been well-validated. This systematic review was performed to evaluate the clinical utility of the FCG.

A computerized search of the PubMed and Scopus databases was performed to identify all studies evaluating the utility of the FCG in surgically resected IPMN. IPMN were stratified according to the FCG as high risk (HR), worrisome risk (WR), and low risk (LR). HR and WR IPMN were termed FCG+ve and LR IPMN were termed FCG-ve.

Seven studies analyzing 1,382 patients were included. There were 402 malignant neoplasms (29%), including 242 invasive IPMNs. There were 1,000 IPMN classified as FCG+ve. The FCG+ve group had a positive predictive value (PPV) ranging from 27 to 62% and the FCG-ve group had negative predictive value ranging from 82 to 100%. Pooled analysis demonstrated that there was 362 of 1,000 (36%) malignant FCG+ve IPMN and 342 of 382 (90%) benign FCG-ve IPMN. PPV of the HR group and the WR groups alone were 104 of 158 (66%) and 75 of 261 (29%), respectively. Forty of 382 (11%), including 22 (6%) invasive FCG-ve IPMN, were malignant. Twenty-six malignant including 18 invasive FCG-ve IPMN were reported from a single study. When the results from this study were excluded, there were only 14 of 241 malignant neoplasms (6%), including 4 of 241 (2%) invasive FCG-ve IPMN in the remaining 6 studies.

The FCG+ve criteria had a similarly low PPV compared with the 2006 consensus criteria. Stratification of IPMN into HR and WR groups resulted in a higher PPV in the HR group. Some malignant and even invasive IPMN may be missed by the FCG criteria.

The management of intraductal papillary mucinous neoplasms (IPMN) is presently evolving as a result of the improved understanding of the natural history and biological behavior of the different pancreatic cystic neoplasms; and better preoperative diagnosis of these neoplasms due to advancement in preoperative diagnostic tools. International consensus guidelines for the management of IPMN were first formulated in 2006 and subsequently revised in 2012. Both these guidelines were constructed based on expert opinion and not on robust clinical data. The main limitation of the original Sendai guidelines was that it had a low positive predictive value resulting in many benign neoplasms being resected. Hence, these guidelines were revised in 2012. However, although the updated guidelines resulted in an improvement in the positive predictive value over the Sendai Guidelines, the results of several studies validating these guidelines demonstrated that its positive predictive value remained low. Furthermore, although both guidelines were associated with high negative predictive values, several investigators have demonstrated that some malignant IPMNs may be missed. Finally, it is imperative to emphasize that major considerations when managing a patient with IPMN including the patient's surgical risk, life-expectancy and even cost of investigations are not taken into account in current guidelines. The management of a patient with IPMN should be individualized and tailored according to a patient's risk benefit profile for resection vs surveillance.

Widespread use of cross-sectional imaging and increasing age of the general population has increased the number of detected pancreatic cystic lesions. However, several pathological entities with a variety in malignant potential have to be discriminated to allow clinical decision making. Discrimination between mucinous pancreatic cystic neoplasms (PCNs) and nonmucinous pancreatic lesions is the primary step in the clinical work-up, as malignant transformation is mostly associated with mucinous PCN. We performed a retrospective analysis of all resected PCN in our tertiary center from 2000 to 2014, to evaluate preoperative diagnostic performance and the results of implementation of the consensus guidelines over time. This was followed by a prospective cohort study of patients with an undefined pancreatic cyst, where the added value of cytopathological mucin evaluation to carcinoembryonic antigen (CEA) in cyst fluid for the discrimination of mucinous PCN and nonmucinous cysts was investigated. Retrospective analysis showed 115 patients operated for a PCN, with a correct preoperative classification in 96.2% of the patients. High-grade dysplasia or invasive carcinoma was observed in only 32.3% of mucinous PCN. In our prospective cohort (n = 71), 57.7% of patients were classified as having a mucinous PCN. CEA ≥ 192 ng/mL had an accuracy of 63.4%, and cytopathological mucin evaluation an accuracy of 73.0%. Combining these 2 tests further improved diagnostic accuracy of a mucinous PCN to 76.8%. CEA level and mucin evaluation were not predictive of the degree of dysplasia. These findings show that adding cytopathology to cyst fluid biochemistry improves discrimination between mucinous PCN and nonmucinous cysts.