Development of ductal carcinoma of the pancreas during follow-up of branch duct intraductal papillary mucinous neoplasm of the pancreas

Pancreatic Fat Content Detected by Computed Tomography and Its Significant Relationship With Intraductal Papillary Mucinous Neoplasm

OBJECTIVES

Intraductal papillary mucinous neoplasms (IPMNs) are premalignant lesions of pancreatic ductal adenocarcinomas (PDACs). Fat accumulation in the pancreas is increasingly recognized as a cause of PDAC. We aimed to identify factors that are relevant between IPMN and metabolic-related factors, including pancreatic fat.

METHODS

The database for 781 subjects who underwent a health checkup and upper abdominal magnetic resonance imaging was searched and computed tomography attenuation indexes (pancreatic and spleen attenuation, pancreas-to-spleen attenuation ratio) were decided by measuring the regions of interest in the pancreas and spleen on nonenhanced images, using Hounsfield units. Eighty-five subjects from each of the IPMN and noncyst groups were matched for age, sex, and glycemic status and statistically compared in clinical characteristics.

RESULTS

There was no difference in metabolic-related factors except for apolipoprotein A1 and high-density lipoprotein cholesterol between the 2 groups in univariate analysis. Multivariate logistic regression analysis showed that both indexes were significantly associated with IPMN (odds ratio, 0.905 [95% confidence intervals, 0.851-0.963; P = 0.002]; odds ratio, 0.006 [95% confidence intervals, 0.000-0.152; P = 0.002]).

CONCLUSIONS

Pancreatic fat content measured by computed tomography was significantly associated with IPMN. These results suggest that IPMN may develop secondary to pancreatic steatosis that could be an overlapping risk factor for PDAC and IPMN.

Value of additional endoscopic ultrasonography for surveillance after surgical removal of intraductal papillary mucinous neoplasms

BACKGROUND AND AIM

This study evaluated the utility of endoscopic ultrasonography (EUS) combined with contrast-enhanced harmonic EUS (CH-EUS) for surveillance of the remnant pancreas after surgery for intraductal papillary mucinous neoplasm (IPMN).

METHODS

This was a single-center, retrospective, descriptive study. A total of 134 consecutive patients who underwent surgical resection for IPMN between April 2009 and March 2015 were evaluated. Rates of recurrence and development of IPMN-concomitant pancreatic ductal adenocarcinoma (PDAC) during follow up were assessed. Clinical findings of patients with recurrence or development of PDAC were also evaluated.

RESULTS

Of 134 resected IPMN 56 (41.8%) and 78 (58.2%) were classified as benign and malignant, respectively. Patients were followed up for a median of 29 months, 33 (24.6%) by both contrast-enhanced computed tomography (CE-CT) and EUS, and 101 (75.4%) by computed tomography (CT) alone. Thirteen patients (9.7%) showed tumor recurrence, five with intra-pancreatic recurrence and eight with extra-pancreatic metastases. An enhancing mural nodule within the dilated main pancreatic duct was successfully detected by EUS in one patient, but not by CE-CT. Two patients developed IPMN-concomitant PDAC during follow up. EUS combined with CH-EUS successfully detected small IPMN-concomitant PDAC in two patients, whereas these lesions were not detected by CT. CH-EUS was useful for better visualization of the margins of IPMN-concomitant PDAC in one of these two patients.

CONCLUSION

Endoscopic ultrasonography combined with CH-EUS may improve follow up of patients with resected IPMN.

Multifocal cysts and incidence of pancreatic cancer concomitant with intraductal papillary mucinous neoplasm

OBJECTIVES

The present study was conducted in order to elucidate the relationship between the number of cyst-existing regions and incidence of pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm (IPMN), which currently remains unclear.

METHODS

Subjects comprised 141 patients undergoing resection for IPMN (Non-invasive IPMN (IPMN with low-to high-grade dysplasia): N = 94, invasive IPMN: N = 31, and PDAC concomitant with IPMN: N = 16) between November 2000 and February 2017. A logistic regression analysis was performed to assess the relationship between the number of cyst-existing regions (one region/two or more regions) and incidence of PDAC concomitant with IPMN, adjusted by clinical characteristics. Cyst-existing regions were defined by the number of anatomical parts of the pancreas: the head/body/tail of the pancreas.

RESULTS

Multiple cyst-existing regions (two or more regions) correlated with the incidence of PDAC concomitant with IPMN (PDAC concomitant with IPMN in one region vs. two or more regions: 3/66 vs. 13/75, multivariable odds ratio [OR] = 4.11, 95% confidence interval [CI] = 1.22 to 18.8, P = 0.02). In contrast, multiple cyst-existing regions did not correlate with the incidence of IPMN (invasive IPMN in one region vs. two or more regions: 13/66 vs. 18/75, OR = 1.19, 95% CI = 0.52 to 2.76, P = 0.67).

CONCLUSIONS

Multifocal cysts correlated with the incidence of PDAC concomitant with IPMN, and may be a high-risk factor for PDAC concomitant with IPMN.

Intraductal Papillary Mucinous Neoplasm of the Pancreas as the Main Focus for Early Detection of Pancreatic Adenocarcinoma

For early detection of pancreatic cancer, interests are now focused on the detection of high-risk individuals to undergo screening examinations. Intraductal papillary mucinous neoplasm (IPMN) is a unique dual precursor of pancreatic cancer, characterized by progression to invasive cancer and the development of pancreatic adenocarcinoma either concomitantly (synchronous occurrence) or even after resection of IPMN (metachronous occurrence). Careful examination and surveillance of patients with IPMN may therefore lead to early detection of pancreatic cancer. By reviewing only reports describing detailed breakdown of the morphological types of IPMN and numbers of patients with noninvasive and invasive carcinoma in each type, the rough frequencies of noninvasive carcinoma in main duct IPMNs and branch duct IPMNs (BD-IPMNs) are 20% and 10%, respectively, and those of invasive carcinoma are 40% and 13%, respectively. Roughly 5% of all patients with IPMN had concomitant adenocarcinoma. The real frequency of carcinoma in BD-IPMNs would be far lower because most patients with small asymptomatic BD-IPMNs do not undergo resection. Intraductal papillary mucinous neoplasm can be the main focus for early detection of pancreatic cancer to achieve favorable prognosis after surgical resection. The optimal protocol for surveillance and method for early detection of pancreatic cancer are to be determined.

Curative resection of pancreatic ductal adenocarcinoma developing in the remnant pancreas 13 years after distal pancreatectomy for intraductal papillary mucinous neoplasms: A case report

Intraductal papillary mucinous neoplasms (IPMNs) are characterized by the papillary proliferation of atypical mucinous epithelial cells in the pancreatic ductal system. There are two recurrence patterns following resection of IPMNs: Metachronous multifocal occurrence of IPMNs, and distinct pancreatic ductal adenocarcinoma (PDAC) in the remnant pancreas. Several recent studies investigated the development of distinct PDAC during follow-up evaluation of IPMNs and the incidence rate ranged from 4.5 to 8%. Thus, IMPNs may be a good predictor for the early detection of PDAC during observation or after the resection of IPMNs. We herein report the rare case of a patient who underwent resection of PDAC that developed in the remnant pancreas 13 years after distal pancreatectomy with splenectomy for IPMNs. PDAC may develop in the remnant pancreas after pancreatectomy for IPMNs; thus, careful long-term follow-up with periodic surveillance, at least every 6 months, is warranted.

Early Diagnosis to Improve the Poor Prognosis of Pancreatic Cancer

Pancreatic cancer (PC) has a poor prognosis due to delayed diagnosis. Early diagnosis is the most important factor for improving prognosis. For early diagnosis of PC, patients with clinical manifestations suggestive of PC and high risk for developing PC need to be selected for examinations for PC. Signs suggestive of PC (e.g., symptoms, diabetes mellitus, acute pancreatitis, or abnormal results of blood examinations) should not be missed, and the details of risks for PC (e.g., familial history of PC, intraductal mucin producing neoplasm, chronic pancreatitis, hereditary pancreatitis, or life habit) should be understood. Multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) can be performed for diagnosing PC, but the diagnostic ability of these examinations for PC is limited. Endoscopic diagnostic procedures, such as endoscopic ultrasonography, including fine-needle aspiration, and endoscopic retrograde pancreatocholangiography, including Serial Pancreatic-juice Aspiration Cytologic Examination (SPACE), could be recommended for a detailed examination to diagnose pancreatic carcinoma earlier.

Resection of benign side-branch intraductal papillary mucinous neoplasm of the pancreas-is long term follow-up indicated?: A case report and review of the literature

RATIONALE

Intraductal papillary mucinous neoplasms of the pancreas (IPMNs) are benign cystic tumors with a relevant risk of malignant transformation over time. Currently, follow-up after surgical resection of benign IPMNs remains controversial.

PATIENT CONCERNS

This is a case report of a 68-year-old male who underwent pancreatic head resection for a multicystic side-branch IPMN with low-grade epithelial dysplasia in March 2009 at the Katharinenhospital Stuttgart, Germany.

DIAGNOSES

During postoperative follow-up, a new solid, slightly hypodense lesion in the tail of the pancreas measuring 2.4 cm in diameter was diagnosed in July 2016. Preoperative staging revealed no signs of distant metastasis.

INTERVENTION

Subsequently, the patient underwent pancreatic tail resection including splenectomy. Histology revealed IPMN-associated adenocarcinoma of the pancreas pT3, pN1 (2/24), M0, R0.

OUTCOMES

Patients with IPMN bare a relatively high overall risk of developing pancreatic cancer. The 5-year incidence has been described to be as high as 6.9%. The current Consensus-Guidelines therefore recommend a structural life-time follow-up. In contrast, in 2015 the American Gastroenterological Association (AGA) explicitly states that follow-up is not recommended for resected benign IPMN. Currently, a general and international consensus is lacking.

LESSONS

The presented case demonstrates that even more than 5 years following resection of benign IPMN, pancreatic cancer can occur in a separate location of the pancreatic gland. We believe that IPMNs can be considered as indicator lesions for pancreatic cancer. Patients with resected side-branch IPMN should therefore undergo long term follow-up.

An elevated expression of serum exosomal microRNA-191, - 21, -451a of pancreatic neoplasm is considered to be efficient diagnostic marker

BACKGROUND

Pancreatic cancer is associated with an extremely poor prognosis, so new biomarkers that can detect the initial stages are urgently needed. The significance of serum microRNA (miR) levels in pancreatic neoplasm such as pancreatic cancer and intraductal papillary mucinous neoplasm (IPMN) diagnosis remains unclear. We herein evaluated the usefulness of miRs enclosed in serum exosomes (ExmiRs) as diagnostic markers.

METHODS

The ExmiRs from patients with pancreatic cancer (n = 32) or IPMN (n = 29), and patients without neoplasms (controls; n = 22) were enriched using ExoQuick-TC™. The expression of ExmiRs was evaluated using a next-generation sequencing analysis, and the selected three miRs through this analysis were confirmed by a quantitative real-time polymerase chain reaction.

RESULTS

The expression of ExmiR-191, ExmiR-21 and ExmiR-451a was significantly up-regulated in patients with pancreatic cancer and IPMN compared to the controls (p < 0.05). A receiver operating characteristic curve analysis showed that the area under the curve and the diagnostic accuracy of ExmiRs were 5-20% superior to those of three serum bulky circulating miRs (e.g.; ExmiR-21: AUC 0.826, accuracy 80.8%. Circulating miR-21: AUC 0.653, accuracy 62.3%). In addition, high ExmiR-451a was associated with mural nodules in IPMN (p = 0.010), and high ExmiR-21 was identified as a candidate prognostic factor for the overall survival (p = 0.011, HR 4.071, median OS of high-ExmiR-21: 344 days, median OS of low-ExmiR-21: 846 days) and chemo-resistant markers (p = 0.022).

CONCLUSIONS

The level of three ExmiRs can thus serve as early diagnostic and progression markers of pancreatic cancer and IPMN, and considered more useful markers than the circulating miRs (limited to these three miRs).

Natural history of pancreatic cystic lesions: A multicenter prospective observational study for evaluating the risk of pancreatic cancer

BACKGROUND AND AIM

The aim of this study is to elucidate the natural history of pancreatic cystic lesions (PCLs), including branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN), via midterm follow-up analysis of a multicenter prospective observational study (NSPINAL study).

METHODS

From July 2011 to October 2016, 881 patients with PCLs were enrolled in NSPINAL study, and 664 patients with > 12 months of follow up were analyzed. Every patient was asymptomatic, and endoscopic ultrasound was performed at the initial diagnosis to exclude high-risk individuals. Follow up included endoscopic ultrasound, computed tomography, or magnetic resonance imaging at least once a year. Serial morphological changes and the pancreatic cancer (PC) incidence, including malignant progression of PCLs, were evaluated.

RESULTS

The 664 patients (358 men) were followed for a median of 33.5 months (interquartile range 29). The cyst and main pancreatic duct sizes were 16.6 ± 9.3 and 2.3 ± 1.0 mm, respectively. Morphologically, 518 cases were multilocular, 137 were unilocular, and 9 had a honeycomb pattern; 269 cases involved multifocal lesions. Ninety-six patients (14.5%) showed worsening progression on imaging. There were two resectable and four unresectable cases of pancreatic ductal adenocarcinoma and three cases of malignant BD-IPMN. The 3-year risk of developing PC was 1.2%. The standardized incidence ratio for PC among PCLs was 10.0 (95% confidence interval 3.5-16.5), and the standardized incidence ratio among BD-IPMN was 16.6 (95% confidence interval 5.1-28.1). Multivariate analysis showed that development of symptoms and worsening progression were significant predictors of PC.

CONCLUSIONS

Malignant progression of PCLs, including PC development, is not uncommon. Patients with PCLs should be carefully monitored to detect pancreatic ductal adenocarcinoma at early stages.

Surveillance of patients with intraductal papillary mucinous neoplasm with and without pancreatectomy with special reference to the incidence of concomitant pancreatic ductal adenocarcinoma

BACKGROUND

The presence of an intraductal papillary mucinous neoplasm is important in the detection of concomitant pancreatic ductal adenocarcinoma. The aim of this study was to elucidate the incidence and timing of development of concomitant pancreatic ductal adenocarcinoma in patients with and without pancreatectomy for intraductal papillary mucinous neoplasm.

METHODS

We reviewed retrospectively the surveillance data for 22 patients who underwent pancreatectomy for pancreatic ductal adenocarcinoma concomitant with intraductal papillary mucinous neoplasm (pancreatic ductal adenocarcinoma-resection group), 180 who underwent pancreatectomy for intraductal papillary mucinous neoplasm (intraductal papillary mucinous neoplasm-resection group), and 263 whose intraductal papillary mucinous neoplasms were left untreated (nonresection group). The incidence and timing of the development of a concomitant pancreatic ductal adenocarcinoma during the surveillance of patients with and without partial pancreatectomy for intraductal papillary mucinous neoplasm were investigated using the Kaplan-Meier method.

RESULTS

During a median surveillance period of 40 months (range 6-262 months), 5 patients in the pancreatic ductal adenocarcinoma-resection group, 6 in the intraductal papillary mucinous neoplasm-resection group, and 8 in the nonresection group developed concomitant pancreatic ductal adenocarcinoma. The estimated 5-year (17%) and 10-year (56%) cumulative incidences of secondary pancreatic ductal adenocarcinoma in the pancreatic ductal adenocarcinoma-resection group were significantly greater than those in the other two groups (P < .01). Conversely, the difference in the estimated cumulative incidence of concomitant pancreatic ductal adenocarcinoma between the intraductal papillary mucinous neoplasm-resection and nonresection groups was not significant (5-year, 5.0% vs 2.2%; 10-year, 5.0% vs 8.7%; P = .87).

CONCLUSION

Long-term (≥5-year) surveillance in patients with intraductal papillary mucinous neoplasm is necessary and important because of the potential for development of concomitant pancreatic ductal adenocarcinoma. Those with a history of resection of concomitant pancreatic ductal adenocarcinoma at the time of the initial operation are at quite high risk for the development of secondary pancreatic ductal adenocarcinoma.

Long-term Risk of Pancreatic Malignancy in Patients With Branch Duct Intraductal Papillary Mucinous Neoplasm in a Referral Center

BACKGROUND & AIMS

Little is known about the development of branch duct intraductal papillary mucinous neoplasms (BD-IPMNs). We evaluated long-term outcomes of a large cohort of patients with BD-IPMNs to determine risk of malignancy and define a subset of low-risk BD-IPMNs.

METHODS

We performed a retrospective analysis of data from 577 patients with suspected or presumed BD-IPMN under surveillance at the Massachusetts General Hospital. Patients underwent cross-sectional imaging analysis at 3 months or later after their initial diagnosis. The diagnosis of BD-IPMN was based on the presence of unilocular or multilocular cysts of the pancreas and a non-dilated main pancreatic duct (<5 mm). We collected demographic, clinical, and pathology data. Cysts were characterized at the time of diagnosis and during the follow-up period. Follow-up duration was time between initial cyst diagnosis and date of last visit or death for patients without development of pancreatic cancer, date of surgery for patients with histologically confirmed malignancy, or date of first discovery of malignancy by imaging analysis for patients with unresectable tumors or who underwent neoadjuvant treatment before surgery. The primary outcome was risk of malignancy, with a focus on patients followed for 5 years or more, compared with that of the US population, based on standardized incidence ratio.

RESULTS

Of the 577 patients studied, 479 (83%) were asymptomatic at diagnosis and 363 (63%) underwent endoscopic ultrasound at least once. The median follow-up time was 82 months (range, 6-329 months) for the entire study cohort; 363 patients (63%) underwent surveillance for more than 5 years, and 121 (21%) for more than 10 years. Malignancies (high-grade dysplasia or invasive neoplasm) developed after 5 years in 20 of 363 patients (5.5%), and invasive cancer developed in 16 of 363 patients (4.4%). The standardized incidence ratio for patients with BD-IPMNs without worrisome features of malignancy at 5 years was 18.8 (95% confidence interval, 9.7-32.8; P < .001). One hundred and eight patients had cysts ≤1.5 cm for more than 5 years of follow-up; only 1 of these patients (0.9%) developed a distinct ductal adenocarcinoma. By contrast, among the 255 patients with cysts >1.5 cm, 19 (7.5%) developed malignancy (P = .01).

CONCLUSIONS

In a retrospective analysis of patients with BD-IPMNs under surveillance, their overall risk of malignancy, almost 8%, lasted for 10 years or more, supporting continued surveillance after 5 years. Cysts that remain ≤1.5 cm for more than 5 years might be considered low-risk for progression to malignancy.

Overdiagnosis: An Understudied Issue in Hepatocellular Carcinoma Surveillance

Overdiagnosis, the detection of clinically insignificant disease that would not otherwise impact the patient's lifespan, is a phenomenon that has been described in several solid tumors, such as prostate, breast, thyroid, and lung cancers. Population-based efforts to reduce hepatocellular carcinoma (HCC) mortality in cirrhosis patients by screening and early detection may result in the overdiagnosis of HCC. One of the harms of overdiagnosis is subsequent overtreatment, which can result in increased costs, as well as physical side effects, psychological harms, and poorer quality of life. In this review, the authors explore the potential for overdiagnosis in HCC.

Progression of Unresected Intraductal Papillary Mucinous Neoplasms of the Pancreas to Cancer: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

It is not clear how best to manage patients with low-risk intraductal papillary mucinous neoplasms (IPMNs) of the pancreas because little is known about IPMN progression to cancer. We sought to determine the cumulative incidence of development of pancreatic cancer in persons with unresected IPMNs (particularly low-risk IPMNs).

METHODS

We performed a systematic search of the MEDLINE and Embase databases through November 30, 2016 for studies reporting the cumulative incidence of pancreatic cancer in patients with unresected IPMNs or studies that provided data in sufficient detail for us to calculate cumulative incidence values. We categorized patient series as studies on low-risk IPMNs (lesions without main pancreatic duct involvement or mural nodules) or non-low-risk IPMNs. We calculated meta-analytic cumulative incidence values for pancreatic cancer at 1, 3, 5, and 10 years of follow-up by using the inverse variance method and random-effects model.

RESULTS

Among 1514 articles screened, we identified 10 studies of low-risk IPMNs (n = 2411) and 9 studies of non-low-risk IPMNs (n = 825). In studies of low-risk IPMNs, the meta-analytic cumulative incidence values for pancreatic cancer were 0.02% at 1 year (95% confidence interval [CI], 0.0%-0.23%; I²= 0.0%), 1.40% at 3 years (95% CI, 0.58%-2.48%; I² = 58.5%), 3.12% at 5 years (95% CI, 1.12%-5.90%; I² = 88.0%), and 7.77% at 10 years (95% CI, 4.09%-12.39%; I² = 79.8%). These values were much higher in studies of non-low-risk IPMNs; cumulative incidence values for pancreatic cancer were 1.95% at 1 year (95% CI, 0.0%-5.99%; I² = 84.2%), 5.69% at 3 years (95% CI, 1.10%-12.77%; I² = 89.9%), 9.77% at 5 years (95% CI, 3.04%-19.27%; I² = 92.0%), and 24.68% at 10 years (95% CI, 14.87%-35.90%; I² = 74.3%). The pooled cumulative incidence steadily increased linearly as the follow-up duration increased.

CONCLUSIONS

In a systematic review and meta-analysis, we found that low-risk IPMNs have almost 8% chance of progressing to pancreatic cancer within 10 years, and higher-risk IPMNs have almost 25% chance of progressing to cancer in 10 years; incidence values increase linearly with time. Continued long-term surveillance is therefore vital for patients with low-risk IPMNs.

Endoscopic Ultrasound Imaging for Diagnosing and Treating Pancreatic Cysts

Cystic pancreatic lesions are increasingly diagnosed owing to the abundant use of cross-sectional imaging. Given their malignant potential, true pancreatic cysts should be considered for resection or periodic follow-up. Cystic lesions of the pancreas (CLPs) require further evaluation and management. Therefore, it is important to establish a solid diagnosis at the time of detection. Endoscopic ultrasound examination is the imaging modality of choice. Fine needle aspiration provides fluid for cytologic, biochemical, and molecular assays to classify lesions and predict biological behavior. This review provides an overview of the diagnosis and management of various types of commonly encountered true CLPs.

Fukuoka criteria accurately predict risk for adverse outcomes during follow-up of pancreatic cysts presumed to be intraductal papillary mucinous neoplasms

OBJECTIVE

Fukuoka consensus guidelines classify pancreatic cystic lesions (PCLs) presumed to be intraductal papillary mucinous neoplasms (IPMNs) into Fukuoka positive (FP) (subgroups of high-risk (HR) and worrisome features (WFs)) and Fukuoka negative (FN) (non-HR feature/WF cysts). We retrospectively estimated 5-year risk of pancreatic cancer (PC) in FN, WF and HR cysts of patients with PCL-IPMN.

DESIGN

From Mayo Clinic databases, we randomly selected 2000 patients reported to have a PCL; we excluded inflammatory or suspected non-IPMN cysts and those without imaging follow-up. We re-reviewed cross-sectional imaging and abstracted clinical and follow-up data on PCL-IPMNs. The study contained 802 patients with FN cysts and 358 with FP cysts.

RESULTS

Patients with PCL-IPMN had median (IQR) follow-up of 4.2 (1.8-7.1) years. Among FN cysts, 5-year PC risk was low (2-3%) regardless of cyst size (p=0.67). After excluding events in the first 6 months, 5-year PC risk remained low (0-2%) regardless of cyst size (p=0.61). Among FP cysts, HR cysts (n=66) had greater 5-year PC risk than WF cysts (n=292) (49.7% vs 4.1%; p<0.001). In HR cysts, 3-year PC risk was greatest for obstructive jaundice versus enhancing solid component or main pancreatic duct >10 mm (79.8% vs 37.3% vs 39.4%, respectively; p=0.01).

CONCLUSIONS

Fukuoka guidelines accurately stratify PCL-IPMNs for PC risk, with FN cysts having lowest and HR cysts having greatest risk. After 6-month follow-up, WF and FN cysts had a low 5-year PC risk. Surveillance strategies should be tailored appropriately.

Incidental, Small (< 3 cm), Unilocular, Pancreatic Cysts: Factors That Predict Lesion Progression during Imaging Surveillance

OBJECTIVE

To explore the features that predict size increase and development of potential malignant features in incidentally detected, unilocular cystic pancreatic lesions (CPLs) less than 3 cm in diameter, during subsequent follow-up.

MATERIALS AND METHODS

We retrieved data of patients diagnosed with unilocular CPLs less than 3 cm in diameter during the period from November 2003 through December 2014, using a computerized search. All serial CT and MR images were analyzed to identify the number, size, and location of CPLs; dilatation of the main pancreatic duct; and occurrence of worrisome features and high-risk stigmata of malignancy in the lesion. The characteristics of CPLs were compared between the increase (i.e., size increase during subsequent follow-up) and no-increase groups. For CPLs in the increase group, subgroup analysis was performed according to the lesion size at the last follow-up (< 3 cm vs. ≥ 3 cm).

RESULTS

Among 553 eligible patients, 132 (23.9%) had CPLs that increased in size, and 421 (76.1%) had CPLs that did not, during follow-up. Of the 132, 12 (9.1%) CPLs increased to diameters ≥ 3 cm at the final follow-up. Among the various factors, follow-up duration was a significant independent factor for an interval size increase of CPLs (p < 0.001). In the increase group, initial cyst size was a significant independent factor to predict later size increase to or beyond 3 cm in diameter (p < 0.001), and the initial cyst diameter ≥ 1.5 cm predicted such a growth with a sensitivity and specificity of 83% and 72%, respectively. No significant factors to predict the development of potential malignant features were identified.

CONCLUSION

Follow-up duration was associated with an interval size increase of CPLs. Among the growing CPLs, initial cyst size was associated with future lesion growth to and beyond 3 cm.

[Branch duct intraductal papillary mucinous neoplasm - contra resection]

Due to improvements in imaging modalities the diagnosis of branch duct intraductal papillary mucinous neoplasms (BD-IPMN) has been significantly increased in recent years. A BD-IPMN is frequently diagnosed as an incidental finding in asymptomatic patients. The optimal management of BD-IPMN is the subject of controversial discussions. Numerous studies have shown that an individualized therapeutic strategy with a follow-up observation of most BD-IPMNs is feasible and safe, considering age, comorbidities and patient preference. An accurate evaluation of BD-IPMN with a detailed anamnesis, high-resolution imaging techniques and endoscopic ultrasound is necessary. Symptomatic patients as well as patients with so-called high-risk stigmata should undergo resection. Asymptomatic patients with so-called worrisome features can either undergo surveillance or surgical resection, taking age and comorbidities into account. For BD-IPMN patients without high-risk stigmata and worrisome features and showing no symptoms, surveillance of the pancreatic lesion is the preferred approach. The high prevalence of BD-IPMN, limitations in differential diagnostics, an overestimation of the risk of malignancy due to an overrepresentation of symptomatic and suspected BD-IPMN in resected cohorts, an overestimated role of BD-IPMN as precursor lesions for pancreatic carcinoma and evidence of the safety of follow-up surveillance, underline the enormous importance of surveillance. Based on this and considering the background of a notable mortality and morbidity of pancreatic surgery, aggressive management with prophylactic surgical resection is not justified for all BD-IPMN, in particular for low-risk lesions.

Targeted DNA Sequencing Reveals Patterns of Local Progression in the Pancreatic Remnant Following Resection of Intraductal Papillary Mucinous Neoplasm (IPMN) of the Pancreas

OBJECTIVE

The aim of this study was to characterize patterns of local progression following resection for pancreatic intraductal papillary mucinous neoplasms (IPMN) using targeted next-generation sequencing (NGS).

BACKGROUND

Progression of neoplastic disease in the remnant pancreas following resection of IPMN may include development of a new IPMN or ductal adenocarcinoma (PDAC). However, it is not clear whether this progression represents recurrence of the same neoplasm or an independent second neoplasm.

METHODS

Targeted-NGS on genes commonly mutated in IPMN and PDAC was performed on tumors from (1) 13 patients who developed disease progression in the remnant pancreas following resection of IPMN; and (2) 10 patients who underwent a resection for PDAC and had a concomitant IPMN. Mutations in the tumors were compared in order to determine the relationship between neoplasms. In parallel, clinical and pathological characteristics of 260 patients who underwent resection of noninvasive IPMN were reviewed to identify risk factors associated with local progression.

RESULTS

We identified 3 mechanisms underlying local progression in the remnant pancreas: (1) residual microscopic disease at the resection margin, (2) intraparenchymal spread of neoplastic cells, leading to an anatomically separate but genetically related recurrence, and (3) multifocal disease with genetically distinct lesions. Analysis of the 260 patients with noninvasive IPMNs showed that family history of pancreatic cancer (P = 0.027) and high-grade dysplasia (HGD) (P = 0.003) were independent risk factors for the development of an IPMN with HGD or an invasive carcinoma in the remnant pancreas.

CONCLUSIONS

Using NGS, we identify distinct mechanisms for development of metachronous or synchronous neoplasms in patients with IPMN. Patients with a primary IPMN with HGD or with positive family history are at an increased risk to develop subsequent high-risk neoplasms in the remnant pancreas.

[Branch duct intraductal papillary mucinous neoplasm - surgical approach]

Due to increasing precision of modern imaging modalities, intraductal papillary mucinous neoplasms (IPMN) of the pancreas are found with increasing prevalence. Despite their malignant potential IPMN are often kept under surveillance and are not immediately resected. The 2012 International Consensus Guidelines of Fukuoka have been widely accepted for the management of IPMN. They recommend surgical resection for branch duct IPMN with "high risk stigmata", while branch duct IPMN with "worrisome features" should undergo observation without immediate resection. Consequently, patients with asymptomatic branch duct IPMN and a presumed low malignant potential mostly undergo primary surveillance to avoid surgery-related morbidity and mortality following pancreatic resection; however, with respect to the cumulative risk of malignant transformation over time, surgical resection might also be indicated for patients with branch duct IPMN with "worrisome features". This article discusses the indications for surgery and different options of resection of branch duct IPMN.

Validation of the American Gastroenterological Association guidelines on management of intraductal papillary mucinous neoplasms: more than 5 years of follow-up

OBJECTIVES

Recent guidelines suggest that imaging surveillance be conducted for 5 years for patients with at most one high-risk feature. If there were no significant changes, surveillance is stopped. We sought to validate this follow-up strategy.

METHODS

In study 1, data were analysed for 392 patients with intraductal papillary mucinous neoplasms (IPMNs) and at most one high-risk feature who were periodically followed up for more than 1 year with imaging tests. In study 2, data were analysed for 159 IPMN patients without worsening high-risk features after 5 years (stop surveillance group).

RESULTS

In study 1, pancreatic cancer (PC) was identified in 12 patients (27.3%) in the endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) indication group and none in the non-EUS-FNA indication group (P < 0.01). In the EUS-FNA indication group, 11 patients (25%) died, whereas 29 (8.3%) died in the non EUS-FNA indication group (P < 0.01). In study 2 (stop surveillance group), PC was identified in three patients (1.9%) at 84, 103 and 145 months.

CONCLUSIONS

PC risk and mortality for IPMNs not showing significant change for 5 years is likely to be low, and the non-EUS-FNA indication can provide reasonable decisions. However, three patients without worsening high-risk features for 5 years developed PC. The stop surveillance strategy should be reconsidered.

KEY POINTS

• The AGA guidelines provide reasonable clinical decisions for the EUS-FNA indication. • In stop surveillance group, PC was identified in 3 patients (1.9%). • In stop surveillance group, 2 of 3 PC patients died from PC. • Risk of pancreatic cancer in "stop surveillance" group is not negligible.

Revisions of international consensus Fukuoka guidelines for the management of IPMN of the pancreas

The management of intraductal papillary mucinous neoplasm (IPMN) continues to evolve. In particular, the indications for resection of branch duct IPMN have changed from early resection to more deliberate observation as proposed by the international consensus guidelines of 2006 and 2012. Another guideline proposed by the American Gastroenterological Association in 2015 restricted indications for surgery more stringently and recommended physicians to stop surveillance if no significant change had occurred in a pancreatic cyst after five years of surveillance, or if a patient underwent resection and a non-malignant IPMN was found. Whether or not it is safe to do so, as well as the method and interval of surveillance, has generated substantial debate. Based on a consensus symposium held during the meeting of the International Association of Pancreatology in Sendai, Japan, in 2016, the working group has revised the guidelines regarding prediction of invasive carcinoma and high-grade dysplasia, surveillance, and postoperative follow-up of IPMN. As the working group did not recognize the need for major revisions of the guidelines, we made only minor revisions and added most recent articles where appropriate. The present guidelines include updated information and recommendations based on our current understanding, and highlight issues that remain controversial or where further research is required.

Active Surveillance Beyond 5 Years Is Required for Presumed Branch-Duct Intraductal Papillary Mucinous Neoplasms Undergoing Non-Operative Management

OBJECTIVES

To evaluate the results of active surveillance beyond 5 years in patients with branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) without worrisome features (WF) and high-risk stigmata (HRS) undergoing non-operative management.

METHODS

Patients with a minimum follow-up of 5 years who underwent surveillance with at least yearly magnetic resonance imaging were included. New onset of and predictors of WF/HRS during follow-up as well as long-term survival were analyzed.

RESULTS

In all, 144 patients were followed for a median of 84 months. At diagnosis multifocal BD-IPMNs were found in 53% of cases and mean size of the largest cyst was 15.5 mm. Changes during follow-up were observed in 69 patients (48%). New onset of WF/HRS were observed in 26 patients (18%) but the rate of HRS was only 4%. WF and HRS developed after a median follow-up of 71 and 77.5 months from diagnosis, respectively, and without previous changes in 19/26 patients. Independent predictors of WF/HRS development were size at diagnosis>15 mm, increase in number of lesions, main pancreatic duct growth rate ≥0.2 mm/year, cyst growth rate >1 mm/year. Overall, the rate of pancreatic invasive malignancy was 2% and the 12-year disease-specific survival was 98.6%.

CONCLUSIONS

Long-term nonoperative management is safe for BD-IPMNs without WF and HRS. Discontinuation of surveillance cannot be recommended since one out of six patients developed WF/HRS far beyond 5 years of surveillance and without previous relevant modifications. An intensification of follow-up should be considered after 5 years.

Natural history of intraductal papillary mucinous neoplasm and non-neoplastic cyst: long-term imaging follow-up study

BACKGROUND

To identify differences in incidence and mortality of pancreatic cancer (PC) between intraductal papillary mucinous neoplasm (IPMN) and non-neoplastic cyst.

METHODS

Patients with pancreatic cyst (n = 526; 263 with IPMN and 263 with non-neoplastic cyst matched for age, sex, and diagnosis year) were periodically followed-up with imaging. Hazard ratio (HR), standardized incidence ratio (SIR), and standardized mortality ratio (SMR) for PC and PC-related mortality were estimated.

RESULTS

During a mean follow-up of 57.5 months with 3,376 computed tomography scans and 1,079 magnetic resonance imaging scans, 5-year cumulative PC incidence was 4.0% for IPMN and 0% for non-neoplastic cyst, respectively (HR 5.2; P = 0.031). During a mean follow-up of 73.1 months, 5-year cumulative PC-related mortality was 2.6% for IPMN and 0% for non-neoplastic cyst, respectively (HR 4.5; P = 0.05). Compared with the general population in Japan, patients with IPMN, but not those with non-neoplastic cyst, had significantly increased risks of PC incidence (SIR 22.03) and related mortality (SMR 15.9).

CONCLUSIONS

During long-term imaging follow-up, patients with IPMN developed PC over time, whereas none of the patients with non-neoplastic cyst developed it within 5 years. Compared with the general population, patients with IPMN, but not those with non-neoplastic cyst, were at risk of PC and related mortality.

Comparison of guidelines for intraductal papillary mucinous neoplasm: What is the next step beyond the current guidelines?

Management of intraductal papillary mucinous neoplasm is controversial, and several guidelines have aimed to establish an adequate strategy for surgical resection and surveillance. We compared various intraductal papillary mucinous neoplasm guidelines and considered new matters that are pivotal for improved treatment of intraductal papillary mucinous neoplasm. We identified and compared 11 published guidelines, three of which were major guidelines that mainly referred to the diagnosis and treatment of intraductal papillary mucinous neoplasm (International Association of Pancreatology 2012 guidelines, European Study Group on Cystic Tumours of the Pancreas 2013 guidelines, and American Gastroenterological Association 2015 guidelines). The main concerns of these three guidelines were indication for surgery and follow up of non-resected lesions. Among the differences between the three guidelines, the period of surveillance recommended was the most controversial matter. Meanwhile, several nomograms have been proposed to improve the diagnosis of intraductal papillary mucinous neoplasm from the level of experts' experiences to that of rational systems. We discuss the adequate strategy of surveillance for intraductal papillary mucinous neoplasm with and without pancreatectomy and nomograms aiming to predict the risk of malignancy in patients with intraductal papillary mucinous neoplasm.

Predictive Factors for the Metachronous Development of High-risk Lesions in the Remnant Pancreas After Partial Pancreatectomy for Intraductal Papillary Mucinous Neoplasm

OBJECTIVE

To identify factors predicting the development of high-risk lesions in the remnant pancreas after surgery for intraductal papillary mucinous neoplasm (IPMN).

BACKGROUND

IPMN has unique features, including multifocality, adenoma-carcinoma sequence, and the development of distinct pancreatic ductal adenocarcinoma (PDAC) in the same pancreas. Careful attention should, therefore, be paid to the metachronous occurrence of high-risk lesions, including high-grade dysplasia or invasive carcinoma (HGD/INV) of IPMN and concomitant PDAC in the remnant pancreas after partial pancreatectomy for IPMN.

METHODS

Clinicopathologic and surveillance data for 195 patients who underwent partial pancreatectomy for IPMN were reviewed retrospectively.

RESULTS

Thirteen patients exhibited metachronous development of high-risk lesions including 6 HGD/INV and 7 concomitant PDACs in the remnant pancreas. The 5- and 10-year cumulative incidences of metachronous high-risk lesions in the remnant pancreas were 7.8% and 11.8%, respectively. Twelve of 13 patients had high-risk lesions at the time of initial surgery, and 10 of the 13 IPMNs were located in the distal pancreas. The IPMN subtypes initially resected were gastric in 6 patients, intestinal in 5, and pancreatobililary in the remaining 2. Univariate and multiple regression analyses identified pathologic results of HGD/INV and IPMN located in the distal pancreas as independent predictive factors for metachronous HGD/INV of IPMN, and the pancreatobiliary subtype of IPMN and presence of concomitant PDAC for metachronous PDAC.

CONCLUSIONS

Patients undergoing partial pancreatectomy for IPMN are at high risk of developing lesions requiring surgery in the remnant pancreas, and close, long-term surveillance should be considered in these patients.

Early diagnosis of pancreatic cancer: Current trends and concerns

Early detection of pancreatic cancer (PC) is essential for a better prognosis. Some recent studies have demonstrated that a slight dilatation of the main pancreatic duct (MPD) and small cystic lesions were detected initially in most cases diagnosed at an early stage. Detecting these abnormal findings in cases with high risk factors through an effective screening system including image diagnosis, some biological markers, or familial cancer registrations should contribute to early diagnosis of PC. It has been reported that endoscopic ultrasonography (EUS) is essential for detecting tumors <10 mm with a favorable prognosis. Additionally, EUS‐guided fine‐needle aspiration biopsy is useful for confirming final histological diagnosis. For the diagnosis of stage 0 PC, local irregular stenosis of MPD should be an important initial abnormal sign detected by EUS or magnetic resonance cholangiopancreatography. Cytodiagnosis multiple times using pancreatic juice obtained by endoscopic nasopancreatic drainage should be essential for the final diagnosis. Recently, activities of regional networks between specialist doctors in medical centers and general practitioners for early diagnosis of PC have been reported in Japan. In the future, these activities may play an important role in the early diagnosis of PC.

Natural courses of branch duct intraductal papillary mucinous neoplasm

PURPOSE

The study was done to elucidate the clinico-radiologic predictive factors for cancerous change detected by disease progression (PD) mainly defined by interval increase in cyst size and change of cyst morphology, for branch duct intraductal papillary mucinous neoplasm (BD-IPMN) patients with relatively long-term follow-up.

METHODS

Retrospective analysis of medical records and imaging findings were performed on 107 patients with BD-IPMN enrolled from July 2005 to May 2013, in whom the communication between the cystic lesion and pancreatic duct was confirmed by either endoscopic ultrasonography (EUS), magnetic resonance cholangiopancreatography (MRCP), or endoscopic retrograde cholangiopancreatography (ERCP).

RESULTS

During the mean ± SD follow-up period of 51.5 ± 24.5 months, PD was noticed in 43 (40.2%) of 107 BD-IPMN patients. Among these 107 patients, 21 (19.6%) displayed cancerous change. By univariate analyses, septated/multilocular cyst morphology, cyst size larger than 30 mm, cyst wall thickening, mural nodules, and the presence of symptoms were significant predictive factors for cancerous changes in BD-IPMN patients. A Cox forward stepwise linear regression model revealed that cyst wall thickening (OR 9.187, 95% CI 1.883~44.820, P < 0.01) and mural nodules (OR 6.224, 95% CI 1.311~29.549, P = 0.021) were significant and independent predictive factors for cancerous change in BD-IPMN patients.

CONCLUSIONS

A significant proportion of patients with BD-IPMN showed PD and cancerous change during the long-term follow-up. Cyst wall thickening and mural nodules were significant and independent predictive factors of cancerous change in patients with BD-IPMN.

Low progression of intraductal papillary mucinous neoplasms with worrisome features and high-risk stigmata undergoing non-operative management: a mid-term follow-up analysis

OBJECTIVE

To evaluate mid-term outcomes and predictors of survival in non-operated patients with pancreatic intraductal papillary mucinous neoplasms (IPMNs) with worrisome features or high-risk stigmata as defined by International Consensus Guidelines for IPMN. Reasons for non-surgical options were physicians' recommendation, patient personal choice or comorbidities precluding surgery.

METHODS

In this retrospective, multicentre analysis, IPMNs were classified as branch duct (BD) and main duct (MD), the latter including mixed IPMNs. Univariate and multivariate analysis for overall survival (OS) and disease-specific survival (DSS) were obtained.

RESULTS

Of 281 patients identified, 159 (57%) had BD-IPMNs and 122 (43%) had MD-IPMNs; 50 (18%) had high-risk stigmata and 231 (82%) had worrisome features. Median follow-up was 51 months. The 5-year OS and DSS for the entire cohort were 81% and 89.9%. An invasive pancreatic malignancy developed in 34 patients (12%); 31 had invasive IPMNs (11%) and 3 had IPMN-distinct pancreatic ductal adenocarcinoma (1%). Independent predictors of poor DSS in the entire cohort were age >70 years, atypical/malignant cyst fluid cytology, jaundice and MD >15 mm. Compared with MD-IPMNs, BD-IPMNs had significantly better 5-year OS (86% vs 74.1%, p=0.002) and DSS (97% vs 81.2%, p<0.0001). Patients with worrisome features had better 5-year DSS compared with those with high-risk stigmata (96.2% vs 60.2%, p<0.0001).

CONCLUSIONS

In elderly patients with IPMNs that have worrisome features, the 5-year DSS is 96%, suggesting that conservative management is appropriate. By contrast, presence of high-risk stigmata is associated with a 40% risk of IPMN-related death, reinforcing that surgical resection should be offered to fit patients.

Differential diagnosis between intraductal papillary mucinous neoplasm with an associated invasive carcinoma and pancreatic ductal adenocarcinoma on ultrasonography: the utility of echo intensity and contrast enhancement

Purpose

The aim of this study was to investigate the utility of echo intensity and contrast enhancement in the differential diagnosis between intraductal papillary mucinous neoplasm with an associated invasive carcinoma (IPMN-IC) and pancreatic ductal adenocarcinoma (PDAC) on ultrasonography.

Methods

This study included eight and 37 patients who had pathologically confirmed IPMN-IC and PDAC, respectively, and were enrolled for a comparative analysis of the sonographic features of the tumors. In the quantitative echo intensity evaluation, the two groups were compared with respect to the difference between the tumor intensity and the pancreatic intensity (TI-PI) and between the tumor intensity and the vascular intensity (TI-VI). In the quantitative contrast enhancement evaluation, the increase in echo intensity (ΔTI) and increase in echo intensity per unit of time (slope) were compared between the groups. The echo intensity and contrast enhancement were also compared between the two groups in patients with T3-T4 disease. In addition, the correlations of the histological type, tumor size, stromal type, and T factor with echogenicity and contrast enhancement were analyzed.

Results

IPMN-IC had significantly greater echo intensity and contrast enhancement than PDAC (TI-PI, P=0.004; TI-VI, P=0.001; ΔTI, P=0.012; slope, P=0.002). In T3-T4 disease, IPMN-IC also showed greater echo intensity and faster enhancement than PDAC. Echo intensity and contrast enhancement were correlated with histological type (TI-PI, P=0.003; TI-VI, P<0.001; ΔTI, P=0.007; slope, P<0.001).

Conclusion

IPMN-IC and PDAC can be differentiated by the quantitative evaluation of echo intensity and contrast enhancement.

MDCT vs. MRI for incidental pancreatic cysts: measurement variability and impact on clinical management

PURPOSE

To investigate incidental pancreatic cysts (IPCs) size discrepancy in a cohort of patients receiving both computed tomography (CT) and magnetic resonance imaging (MRI) and its impact on clinical management based on the 2010 American College of Radiology (ACR) guidelines.

METHODS

This was a HIPAA-compliant, retrospective, IRB-approved study. Informed consent was waived. Patients with known IPCs and at least one case-pair, consisting of an abdominal CT and MRI examination within 180 days between 05/1999 and 12/2011, were included. Maximum diameter of cysts was measured in both the CT and MR examinations. A subset of 30 patients was measured by three radiologists independently to assess inter-observer variability. Absolute difference in diameter measurements between CT and MRI was calculated. Influence of cyst size, cyst location, and patient characteristics such as weight, height, and body mass index (BMI) on variability of size measurements were evaluated. Clinical impact in terms of current ACR guidelines was assessed.

RESULTS

Overall, 267 case-pairs of cysts in 113 patients were included in this study. 59/267 cysts were visualized on MRI but not on CT (22.1%, 95% CI 17.1%-27.1%; 32 patients, 64.6 ± 11.7 years, BMI 28.5 ± 4.8 kg/m²), with a median MRI cyst size of 7.8 mm, IQR 6.0-9.0 mm, range 2-17.8 mm. 208 case-pairs in 113 patients with a mean BMI of 26.9 ± 5.1 kg/m² (range 16.9-39.5 kg/m²) and mean cysts size of 13.4 ± 8.1 mm (range 3-49 mm) were seen in both CT and MRI. The mean absolute size difference for IPCs measured on MRI and CT was 2.1 ± 1.8 mm (median 1.5 mm, IQR 0.9-2.9 mm, range 0-9 mm). Absolute size difference between CT and MRI measurements increased with size of the cyst (r = 0.31, p < 0.001), whereas location of the cyst did not influence the absolute difference between CT and MRI measurements (p = 0.44). Patient weight and BMI had a negative correlation with the difference in cyst size between CT and MRI (weight r = -0.17, p = 0.023; BMI r = -0.17, p = 0.027), with cyst measurements being larger on MRI in thin patients and on CT in obese patients. Inter-reader variability was excellent (ICC = 0.99). In 12/208 (5.7%, 95% CI 2.7%-9.1%), variability between CT and MRI would have changed ACR-based follow-up recommendation.

CONCLUSION

There was a median difference of 1.5 mm between measurements of IPCs on CT vs. MRI. If imaging modality was switched during follow-up, variability of measurements may lead to inappropriate change of follow-up regimen in 6% of all cases. A single follow-up CT for incidental IPCs does not seem sufficient due to a high number (22%) of missed IPCs on CT.

Screening for Pancreatic Cancer

Pancreatic cancer (PC) is a highly fatal disease that can only be cured by complete surgical resection. However, most patients with PC have unresectable disease at the time of diagnosis, highlighting the need to detect PC and its precursor lesions earlier in asymptomatic patients. Screening is not cost-effective for population-based screening of PC. Individuals with genetic risk factors for PC based on family history or known PC-associated genetic syndromes, however, can be a potential target for PC screening programs. This article provides an overview of the epidemiology and genetic background of familial PC and discusses diagnostic and management approaches.

Intraductal papillary mucinous neoplasms of the pancreas: reporting clinically relevant features

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas can exhibit a wide spectrum of macroscopic and microscopic appearances. This not only causes occasional difficulties for the reporting pathologist in distinguishing these tumours from other lesions, but is also relevant clinically. As evidence accumulates, it becomes clear that multiple macroscopic and histological features of these neoplasms are relevant to the risk for malignant transformation and, consequently, of prime importance for clinical patient management. The need for detailed reporting is therefore increasing. This review discusses the panoply of gross and microscopic features of IPMN as well as the recommendations from recent consensus meetings regarding the pathology reporting on this tumour entity.

Branch Duct Intraductal Papillary Mucinous Neoplasms of the Pancreas Involving Type 1 Localized Autoimmune Pancreatitis with Normal Serum IgG4 Levels Successfully Diagnosed by Endoscopic Ultrasound-guided Fine-needle Aspiration and Treated without Pancreatic Surgery

We herein report a 68-year-old man with branch duct intraductal papillary mucinous neoplasms of the pancreas (BD-IPMNs) involving type 1 localized autoimmune pancreatitis (AIP) with normal serum IgG4 levels. Although he was referred to our medical center due to suspicion of pancreatic cancer concomitant with BD-IPMNs, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) revealed a mass suspected of being pancreatic cancer to be type 1 AIP. Steroid administration notably reduced the mass. Although the clinical diagnosis of pancreatic masses in patients with IPMN can be occasionally challenging, performing a pathological examination by EUS-FNA may prevent unnecessary pancreatic surgery in cases of possible AIP.

Survival Analysis and Risk for Progression of Intraductal Papillary Mucinous Neoplasia of the Pancreas (IPMN) Under Surveillance: A Single-Institution Experience

Purpose

While surveillance of the majority of patients with IPMN is considered best practice, consensus regarding the duration of follow-up is lacking. This study assessed the survival rate and risk for progression of IPMN under surveillance.

Methods

All patients diagnosed with and surveyed for IPMN between January 2008 and December 2013 were identified and assigned to two groups: patients without indication for surgery (Group 1), and patients whose IPMN required surgery but were inoperable for general reasons (Group 2). Disease progression and survival data were compared between both groups.

Results

In total 503 patients were identified, of whom 444 (88.3%) were followed up. Group 1 included 395 patients, and Group 2 had 49. In Group 1, IPMN-specific 1-, 5-, and 10-year survival rates were 100, 100, and 94.2%, respectively. Four patients died of associated or concomitant pancreatic cancer, and 230 patients (58.2%) experienced disease progression. The 1-, 4-, 10-year cumulative risk for progression and for surgery was 11.2, 70.6, 97.5, and 2.9, 26.2, 72.1%, respectively. In Group 2, the 1-, 5-, 10-year IPMN-specific survival rate was 90.7, 74.8, and 74.8%, respectively.

Conclusions

This study confirmed the safety of surveillance for patients with IPMN who do not require surgery. However, the risk for disease progression and for surgery increases significantly over time. The study results support International and European guidelines not to discontinue IPMN surveillance and validate the European recommendation to intensify follow-up after 5 years. The fairly good prognosis of patients whose IPMN requires surgery but cannot undergo resection suggests a relatively indolent disease biology.

Outcome of long interval radiological surveillance of side branch pancreatic duct-involved intraductal papillary mucinous neoplasm in selected patients

INTRODUCTION

Side branch IPMN (SB-IPMN) of the pancreas has a malignancy rate between 10 and 20%. We hypothesized that surveillance at longer intervals on selected patients with SB-IPMN might be indicated.

METHODS

This is a retrospective study of prospectively collected data of 276 patients presenting from 2000 to 2010. After 2007, we opted to screen our patients with longer intervals, initially at 12 months then 24 months using MR if no "worrisome features" were present.

RESULTS

Complete data sets for 261 patients were analysed and patients were aged 78 (40-91) years. 232 patients had sole SB-IPMN while 92% were incidental (n = 209) and 8% were symptomatic (n = 24). Single SB-IPMN accounted for 84% (n = 195) of all cases; maximum diameter of 15.5 (5-60) mm. The median follow up duration was 46 (32-53) months. Short interval radiological surveillance (3-9 months) was 39% (n = 90), while long interval surveillance (12-36 months) was performed in 61% (n = 142). The rate of pancreatic resection, due to concern for the development of pancreatic cancer, in the short and long interval surveillance groups was 4.4% (n = 4) and 3.5% (n = 5) respectively; p = 0.78.

CONCLUSION

Our data suggests no difference in outcome between long and short interval MR surveillance of SB-IPMN patients.

Management of branch-duct intraductal papillary mucinous neoplasms: a large single-center study to assess predictors of malignancy and long-term outcomes

BACKGROUND AND AIMS

Management of branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) remains challenging. We determined factors associated with malignancy in BD-IPMNs and long-term outcomes.

METHODS

This retrospective cohort study included all patients with established BD-IPMNs by the International Consensus Guidelines (ICG) 2012 and/or pathologically confirmed BD-IPMNs in a tertiary care referral center between 2001 and 2013. Main outcome measures were the association between high-risk stigmata (HRS)/worrisome features (WFs) of the ICG 2012 and malignant BD-IPMNs, performance characteristics of EUS-FNA for the diagnosis of malignant BD-IPMNs, and recurrence and long-term outcomes of BD-IPMN patients undergoing surgery or imaging surveillance.

RESULTS

Of 364 BD-IPMN patients, 229 underwent imaging surveillance and 135 underwent surgery. Among the 135 resected BD-IPMNs, HRS/WFs on CT/magnetic resonance imaging (MRI) were similar between the benign and malignant groups, but main pancreatic duct (MPD) dilation (5-9 mm) was more frequently identified in malignant lesions. On EUS-FNA, mural nodules, MPD features suspicious for involvement, and suspicious/positive malignant cytology were more frequently detected in the malignant group with a sensitivity, specificity, and accuracy of 33%, 94%, and 86%; 42%, 91%, and 83%; and 33% 91%, and 82%, respectively. Mural nodules identified by EUS were missed by CT/MRI in 28% in the malignant group. Patients with malignant lesions had a higher risk of any IPMN recurrence during a mean follow-up period of 131 months (P = .01).

CONCLUSIONS

Among HRS and WFs of the ICG 2012, an MPD size of 5 to 9 mm on CT/MRI was associated with malignant BD-IPMNs. EUS features including mural nodules, MPD features suspicious for involvement, and suspicious/malignant cytology were accurate and highly specific for malignant BD-IPMNs. Our study highlights the incremental value of EUS-FNA over imaging in identifying malignant BD-IPMNs, particularly in patients without WFs and those with smaller cysts. Benign IPMN recurrence was observed in some patients up to 8 years after resection.

Treatment of branch-duct intraductal papillary mucinous neoplasms of the pancreas: state of the art

The diagnosis of branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) has been dramatically increased. BD-IPMNs are frequently discovered as incidental findings in asymptomatic individuals, mainly in elderly patients. An accurate evaluation of BD-IPMNs with high-resolution imaging techniques and endoscopic ultrasound is necessary. Patients with high-risk stigmata (HRS, obstructive jaundice, enhanced solid component) should undergo resection. Patients with worrisome features (WF, cyst size ≥3 cm, thickened enhanced cyst walls, non-enhanced mural nodules, and clinical acute pancreatitis) may undergo either a strict surveillance based on patients' characteristics (age, comorbidities) or surgical resection. Non-operative management is indicated for BD-IPMNs without HRS and WF. Patients with BD-IPMN who do not undergo resection may develop malignant change over time as well as IPMN-distinct pancreatic cancer. However, non-operative management of BD-IPMNs lacking WF and HRS is safe and the risk of malignant degeneration seems relatively low. The optimal surveillance protocol is currently unclear.

Distinction of Invasive Carcinoma Derived From Intraductal Papillary Mucinous Neoplasms From Concomitant Ductal Adenocarcinoma of the Pancreas Using Molecular Biomarkers

OBJECTIVES

To clarify the usefulness of molecular biomarkers for distinguishing invasive carcinoma derived from intraductal papillary mucinous neoplasms (IPMNs [Inv-IPMN]) from concomitant pancreatic ductal adenocarcinoma (PDAC).

METHODS

Data from 19 patients with resected concomitant PDAC were retrospectively reviewed. KRAS/GNAS mutations and immunohistochemical (IHC) expression of p53 and p16/CDKN2A were assessed in both IPMN and distinct PDAC. As controls, KRAS/GNAS mutations and IHC labeling were assessed between invasive and noninvasive components in 1 lesion of 22 independent patients.

RESULTS

KRAS/GNAS mutation status of invasive and noninvasive components in Inv-IPMN was consistent in 18 (86%) of 21 patients. Conversely, mutational patterns in IPMN and distinct PDAC in the same pancreas differed from each other in 17 (89%) of 19. There were 10 (53%) and 8 (42%) of 19 patients who showed the same p53 and p16/CDKN2A staining between concomitant PDAC and distinct IPMN. In the Inv-IPMN cohort, 19 (86%) of 22 patients showed the same IHC expression pattern between the noninvasive and invasive components.

CONCLUSIONS

It may be possible to distinguish Inv-IPMN from concomitant PDAC by assessing these molecular biomarkers. More precise distinction of Inv-IPMN and concomitant PDAC will lead to adequate recognition of the natural history of IPMNs and hence optimal management.

Is It Time to Expand the Role of Total Pancreatectomy for IPMN?

Intraductal papillary mucinous neoplasms (IPMN) are cystic precursors to pancreatic cancer believed to arise within a widespread neoplastic field defect. The tendency for some patients to present with multifocal disease and/or develop additional lesions over time argues in favor of a field defect and complicates surgical management decisions. Surgery usually consists of partial pancreatic resection, which leaves behind a pancreatic remnant at risk for recurrent disease and progression to cancer. As an alternative, total pancreatectomy (TP) provides the most complete oncologic resection, but postoperative morbidity and quality of life (QoL) issues have generally limited its use to only the highest risk patients. Significant progress has been made in the management of the post-TP apancreatic state and studies now show less morbidity with acceptable QoL comparable to type 1 diabetic and post-pancreaticoduodenectomy patients. These improvements do not yet justify the routine use of TP, but they have opened the door for expansion to additional subsets of non-invasive IPMN. Here, we have identified several groups of patients that we believe would benefit from TP over partial resection based on the most current literature.

Risk of pancreatic malignancy and mortality in branch-duct IPMNs undergoing surveillance: A systematic review and meta-analysis

BACKGROUND

Safety of non-operative management for low-risk branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) is debated.

AIM

To perform a systematic review/meta-analysis to determine their risk of developing pancreatic malignancy and of pancreatic malignancy-related deaths.

METHODS

A MEDLINE search was performed and methodology was based on PRISMA statement. Incidence rates of overall pancreatic malignancy, malignant BD-IPMN, IPMN-distinct PDAC, and of pancreatic malignancy-related death rates were calculated by dividing the total number of events by the total number of person-years (pyrs) of follow-up. Heterogeneity was determined by I(2) statistic.

RESULTS

20 studies including 2177 patients were included. Mean follow-up ranged from 29.3 to 76.7 months. Overall, 82 patients (3.7%) developed a pancreatic malignancy with a pooled estimate rate of 0.007/pyrs (I(2)=32.8%). The pooled estimate rate of malignant IPMN was 0.004/pyrs (I(2)=40.8%), and the pooled estimate rate of distinct PDAC 0.002/pyrs (I(2)=0%). The rate of death due to pancreatic malignancy during follow-up was 0.9%, with an overall pooled estimate rate of death of 0.002/pyrs (I(2)=0%).

CONCLUSION

Non-operative management of low-risk BD-IPMN is safe, with a very low risk of malignant transformation of IPMN and of distinct PDAC. The rate of pancreatic malignancy-related mortality is low, particularly when compared with the mortality of pancreatic surgery.

The role of endoscopic ultrasound in pancreatic cancer screening

Pancreatic cancer (PC) is a highly lethal cancer. Despite a significant advancement in cancer treatment, the mortality rate of PC is nearly identical to the incidence rates. Early detection of tumor or its precursor lesions with dysplasia may be the most effective approach to improve survival. Screening strategies should include identification of the population at high risk of developing PC, and an intense application of screening tools with adequate sensitivity to detect PC at an early curable stage. Endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) seem to be the most promising modalities for PC screening based on the data so far. EUS had an additional advantage over MRI by being able to obtain tissue sample during the same examination. Several questions remain unanswered at this time regarding the age to begin screening, frequency of screening, management of asymptomatic pancreatic lesions detected on screening, timing of resection, and extent of surgery and impact of screening on survival. Novel techniques such as needle-based confocal laser endomicroscopy (nCLE), along with biomarkers, may be helpful to identify pancreatic lesions with more aggressive malignant potential. Further studies will hopefully lead to the development of strategies combining EUS with other technological/biological advancements that will be cost-effective and have an impact on survival.

International consensus on the management of intraductal papillary mucinous neoplasm of the pancreas

International consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas revised in 2012 (Fukuoka consensus) seem to be accepted well worldwide. Division of various factors to predict malignant transformation into two categories, i.e., "high-risk stigmata" and "worrisome features", is also accepted as practically useful for stratifying the risk factors. Our current interest resides in the development of noninvasive and/or invasive pancreatic cancer in areas of the pancreas distinct from IPMN. Invasive pancreatic cancers derived from and concomitant with IPMN should be distinguished to clarify the incidence of each entity, although some more definitive method for differentiation has to be devised in some cases where histological distinction is obscure. IPMN is a clue to early detection of pancreatic cancer. The optimal surveillance protocol for IPMN on observation should be determined in consideration of both of these different pancreatic cancers.

Imaging patterns of intraductal papillary mucinous neoplasms of the pancreas: an illustrated discussion of the International Consensus Guidelines for the Management of IPMN

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.

Effective screening for early diagnosis of pancreatic cancer

Diagnosis of pancreatic cancer (PC) at an early stage with curative surgery should improve long-term patient outcome. At present, improving survival should lie in identifying those cases with high-risk factors or precursor lesions through an effective screening including ultrasonography, some biological markers, or national familial pancreatic cancer registration. Recently, cases with PC < 10 mm with a favorable prognosis have been reported. For the diagnoses of cases with PC < 10 mm, the rate of tumor detection was higher on endoscopic ultrasonography (EUS) than on CT or other modalities, and EUS-guided fine needle aspiration was helpful in confirming the histologic diagnosis. Additionally, for the diagnosis of cases with PC in situ, EUS and magnetic resonance cholangiopancreatography (MRCP) may play important roles in detecting the local irregular stenosis of the pancreatic duct. Cytodiagnosis of pancreatic juice using endoscopic nasopancreatic drainage multiple times may be useful in the final diagnosis.