Main Duct Thresholds for Malignancy Are Different in Intraductal Papillary Mucinous Neoplasms of the Pancreatic Head and Body-Tail

Risk of pancreatic cancer and high-grade dysplasia in resected main-duct and mixed-type intraductal papillary mucinous neoplasms: A prevalence meta-analysis

BACKGROUND

Current guidelines recommend the resection of main duct- (MD) and mixed-type (MT) intraductal papillary mucinous neoplasms (IPMN) based on specific risk criteria to prevent or treat pancreatic cancer in selected patients. This paradigm follows high rates of malignancy observed in published surgical series. The aim of this systematic review and meta-analysis was to provide robust, pooled rates of invasive carcinoma (IC) and high-grade dysplasia (HGD) in resected MD- and MT-IPMNs of the pancreas.

METHODS

The PubMed, Embase, Scopus, Web of Science, and Cochrane CENTRAL databases were systematically searched. Studies that reported rates of IC or HGD, diagnosed by histopathology of surgical specimens, in MD- or MT-IPMNs were included. Pooled prevalence with 95 % confidence interval (95 % CI) was calculated using a random effects model. Galbraith plots were used to evaluate heterogeneity. Risk of bias was assessed using the National Institutes of Health Quality Assessment Tool.

RESULTS

Based on 51 studies, 59 % (95 % CI: 54 %, 64 %) of resected MD- and MT-IPMN had IC or HGD, with IC in up to 39 % (95 % CI: 33 %, 44 %) of lesions and HGD in 20 % (95 % CI: 16 %, 25 %). Most studies were deemed to be of good quality and Galbraith plots demonstrated high concordance.

CONCLUSIONS

These results confirm the rates of IC and HGD in resected MD/MT-IPMNs. However, a significant proportion of patients have benign lesions, and future research is needed to develop precise diagnostics to distinguish between patients with and without high-risk or cancerous disease.

Prediction of main pancreatic duct involvement in intraductal papillary mucinous neoplasms on magnetic resonance imaging

PURPOSE

To evaluate the measurement of main pancreatic duct (MPD) diameter on MRI for predicting MPD involvement in intraductal papillary mucinous neoplasms (IPMN).

METHODS

This retrospective study included 595 patients with surgically confirmed IPMN who underwent preoperative MRI from 2015 to 2022. Three independent readers measured the maximum MPD diameter on two-dimensional axial and coronal T2-weighted imaging. Inter-plane and inter-reader agreements were assessed using the intraclass correlation coefficient (ICC). Multivariable logistic regression identified clinical and radiological factors associated with MPD involvement. Accuracy, sensitivity, and specificity of MPD diameter cutoffs, including the 5-mm threshold from the 2024 International Consensus Guidelines, were calculated.

RESULTS

Of the 595 patients (mean age: 64.6 years ± 8.6, 394 men), 423 (71.1%) had IPMN with MPD involvement, whereas 172 (28.9%) did not have MPD involvement. The mean maximum MPD diameter was 7.9 ± 5.1 mm. Inter-plane agreement was excellent (ICC = 0.977-0.988), as was inter-reader agreement (ICC = 0.963). Only a large MPD diameter on MRI was independently associated with MPD involvement (odds ratio = 1.29 [95% confidence interval; 1.14-1.47], p <.01). Use of a maximum MPD diameter cutoff of ≥ 5 mm for MPD involvement yielded accuracy, sensitivity, and specificity of 76.0%, 79.2%, and 68.0%, respectively.

CONCLUSION

Despite excellent inter-plane and inter-reader agreement, the MRI-based prediction of MPD involvement in IPMN has limitations.

Comparison of clinical characteristics and prognostic factors in two site-specific categories of ampullary cancer

BACKGROUND

Ampullary cancer is a relatively rare malignant tumor in the digestive system. Its incidence has increased in recent years. As for now, its biological characteristics have not been fully clarified. Recent studies have primarily focused on the histological classification and genetic changes, but there are fewer investigations into the differences among site-specific subgroups. The clinicopathological characteristics of ampullary cancer occurring in different positions have not been elucidated. Furthermore, the role of adjuvant therapy in the treatment of patients with ampullary cancer remains controversial.

AIM

To study the clinicopathological features of the two site-specific subgroups of ampullary cancer and explore the factors affecting prognosis.

METHODS

A total of 356 patients who met the inclusion and exclusion criteria were enrolled. Patients were divided into ampulla of Vater cancer (AVC) and duodenal papilla cancer (DPC) based on the gross and microscopic findings. Baseline data, admission examination results, and perioperative outcomes were collected and analyzed. The Kaplan-Meier curve was used for survival analysis. Univariate and multivariate analysis was performed to explore the independent risk factors affecting the overall survival (OS) of both groups.

RESULTS

The preoperative total bilirubin level in patients with AVC was significantly higher than those with DPC (P = 0.04). The OS for patients with DPC was 58.90 ± 38.74 months, significantly longer than 44.31 ± 35.90 months for patients with AVC (P < 0.01). The independent risk factors affecting the OS of AVC included: Preoperative albumin level (P = 0.009), total bilirubin level (P = 0.017), and number of positive lymph nodes (P = 0.005). For DPC, risk factors included: Age (P = 0.004), tumor size (P = 0.023), number of positive lymph nodes (P = 0.010) and adjuvant treatment (P = 0.020). Adjuvant therapy significantly improved the OS rate of patients with DPC, but not for those with AVC.

CONCLUSION

Patients with AVC had a shorter OS compared to those with DPC. The prognosis factors and the role of adjuvant therapy of two groups were different.

Percentage of Pancreatic Cysts on MRI With a Pancreatic Carcinoma: Systematic Review and Meta-Analysis

BACKGROUND

Pancreatic cystic lesions (PCLs) are frequent on MRI and are thought to be associated with pancreatic adenocarcinoma (PDAC) necessitating long-term surveillance based on older studies suffering from selection bias.

PURPOSE

To establish the percentage of patients with PCLs on MRI with a present or future PDAC.

STUDY TYPE

Systematic review, meta-analysis.

POPULATION

Adults with PCLs on MRI and a present or future diagnosis of PDAC were eligible. MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Scopus were searched to April 2022 (PROSPERO:CRD42022320502). Studies limited to PCLs not requiring surveillance, <100 patients, or those with a history/genetic risk of PDAC were excluded.

FIELD STRENGTH/SEQUENCE

≥1.5 T with ≥1 T2-weighted sequence.

ASSESSMENT

Two investigators extracted data, with discrepancies resolved by a third. QUADAS-2 assessed bias. PDAC was diagnosed using a composite reference standard.

STATISTICAL TESTS

A meta-analysis of proportions was performed at the patient-level with 95% confidence intervals (95% CI).

RESULTS

Eight studies with 1289 patients contributed to the percentage of patients with a present diagnosis of PDAC, and 10 studies with 3422 patients to the percentage with a future diagnosis. Of patients with PCLs on MRI, 14.8% (95% CI 2.4-34.9) had a PDAC at initial MRI, which decreased to 6.0% (2.2-11.3) for studies at low risk of bias. For patients without PDAC on initial MRI, 2.0% (1.1-3.2) developed PDAC during surveillance, similar for low risk of bias studies at 1.9% (0.7-3.6), with no clear trend of increased PDAC for longer surveillance durations. For patients without worrisome features or high-risk stigmata, 0.9% (0.1-2.2) developed PDAC during surveillance. Of 10, eight studies had a median surveillance ≥3 years (range 3-157 months). Sources of bias included retrospectively limiting PCLs to those with histopathology and inconsistent surveillance protocols.

DATA CONCLUSION

A low percentage of patients with PCLs on MRI develop PDAC while on surveillance. The first MRI revealing a PCL should be scrutinized for PDAC.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Main pancreatic duct involved IPMN without high-risk factors: how to judge the degree of malignancy based on MPD dilation?

The aim of this study was to evaluate the cutoff value for identifying malignance in main pancreatic duct (MPD)-involved intraductal papillary mucinous neoplasm (IPMN) with an MPD diameter ranging from 5 to 10 mm. Clinical-radiological characteristics of 142 patients, including MPD-involved IPMNs (n = 53) and branch-duct (BD)-IPMNs (n = 89) were analyzed. Logistic regression analysis was used to determine the risk factors of malignant IPMNs and invasive carcinoma. ROC curves were used to identify different cutoffs in terms of preoperative MPD values to predict the presence of invasive carcinoma as well as malignant IPMNs, and the prediction performance was evaluated. For MPD-involved IPMNs (5 mm < MPD < 10 mm), MPD diameter of 7.5 mm for discriminating malignant IPMNs (area under curve [AUC] = 0.67) and 7.7 mm for discriminating invasive IPMNs (AUC = 0.56) were found to be the optimal cutoff values at receiver operating characteristic curve (ROC) analysis. MPD > 7.5 mm and carbohydrate antigen19-9 (Ca19-9) > 37 U/ml were found to be predictors of malignant IPMNs at univariate, and MPD > 7.5 mm was a predictor in multivariate analysis in MPD-involved IPMNs. The AUC of the ROC curve of MPD (7.5 mm) combined with Ca19-9 in identifying malignant IPMNs was 0.73 in MPD-involved IPMNs. MPD (7.5 mm) combined with Ca19-9 performed well in identifying malignant IPMNs in MPD-involved IPMNs.

Clinical Outcomes of Intraductal Papillary Mucinous Neoplasms With Dilatation of the Main Pancreatic Duct

BACKGROUND & AIMS

Dilatation of the main pancreatic duct (MPD) has been a surgical indication for intraductal papillary mucinous neoplasms (IPMNs). Few studies have investigated long-term outcomes of IPMNs with MPD dilatation.

METHODS

Among 3610 patients diagnosed with pancreatic cysts between 1994 and 2021, we identified 2829 IPMN patients, including 282 patients with MPD ≥5 mm, and examined short-term (≤6 months) and long-term risks of pancreatic carcinoma. Utilizing competing risks proportional hazards models, we estimated subdistribution hazard ratios for incidence of pancreatic carcinoma with adjustment for potential confounders.

RESULTS

In analyses of short-term outcomes of the 282 patients with MPD dilatation, 72 (26%) patients were diagnosed with pancreatic carcinoma based on surgical or nonsurgical exploration. During long-term follow-up of 168 patients, we documented 24 (14%) patients diagnosed with pancreatic carcinoma (18 with IPMN-derived carcinoma and 6 with concomitant ductal adenocarcinoma). The patients with the MPD = 5-9.9 mm had cumulative incidence rates of pancreatic carcinoma diagnosis of 8.1% (95% confidence interval [CI], 4.3%-13.5%) and 10.0% (95% CI, 5.5%-15.9%) at 2 and 5 years, respectively; and the patients with the MPD ≥10 mm had the corresponding rates of 16.0% (95% CI, 3.6-36.5%) and 33.3% (95% CI, 10.3%-58.8%). The multivariable subdistribution hazard ratios were 2.78 (95% CI, 1.57-4.90) and 7.00 (95% CI, 2.58-19.0) for the MPD = 5-9.9 mm and ≥10 mm (vs <5 mm), respectively.

CONCLUSIONS

IPMNs with MPD dilatation at baseline were associated with higher prevalence and incidence of pancreatic carcinoma compared with IPMNs with no MPD dilatation.

Threshold of Main Pancreatic Duct Diameter in Identifying Malignant Intraductal Papillary Mucinous Neoplasm by Magnetic Resonance Imaging

Objective: Intraductal papillary mucinous neoplasm (IPMN) is a rare pancreatic lesion. The identification of malignancy is critical for the establishment of treatment strategies. Main pancreatic duct (MPD) diameter is one critical feature for malignant IPMNs. However, the threshold of 1.0 cm is challenged. In this study, we explored independent risk factors and further calculated the threshold of MPD in identifying malignant IPMNs. Method: A total of 151 IPMN patients were included in this retrospective study. Demographic information, clinicopathological features, laboratory testing, and preoperative radiological characteristics by magnetic resonance imaging were collected. The receiver operating characteristic (ROC) curves were performed to determine the MPD diameter's cutoff levels and evaluate the predicted factors' diagnostic ability. Results: A cutoff value of 0.77 cm MPD (an area under the curve (AUC) = 0.746) in all IPMNs and 0.82 cm (AUC = 0.742) in the main duct involved IPMNs was obtained. MPD diameter (odds ratio (OR), 12.67; 95% confidence interval (CI), 4.80-33.48) and the mural nodule (OR, 12.98; 95% CI, 3.18-52.97) were the independent associated factors with high-risk IPMNs. The combined model with MPD and mural nodule showed a better predictive performance than mural nodule or MPD diameter alone (AUC = 0.803 vs 0.619, 0.746). A nomogram was developed and showed good performance (C index = 0.803). Conclusion: Our data show that mural nodule and MPD diameter are independent risk factors in identifying malignant intraductal papillary mucinous neoplasms. A cutoff value of 0.77 cm of MPD diameter may be a threshold value in identifying malignant intraductal papillary mucinous neoplasms or undergoing surgical resection.

Threshold of main pancreatic duct for malignancy in intraductal papillary mucinous neoplasm at head-neck and body-tail

Background

Main pancreatic duct (MPD) dilation is a high-risk stigmata/worrisome feature of malignancy in intraductal papillary mucinous neoplasms (IPMNs). The threshold of MPD diameter in predicting malignancy may be related to the lesion location. This study aimed to separately identify the thresholds of MPD for malignancy of IPMNs separately for the head-neck and body-tail.

Materials and methods

A total of 185 patients with pathologically confirmed IPMNs were included. Patient demographic information, clinical data, and pathological features were obtained from the medical records. Those IPMNs with high-grade dysplasia or with associated invasive carcinoma were considered as malignant tumor. Radiological data including lesion location, tumor size, diameter of the MPD, mural nodule, and IPMN types (main duct, MD; branch duct, BD; and mixed type, MT), were collected on computed tomography or magnetic resonance imaging. Serum carbohydrate antigen 19-9 levels, serum carcinoembryonic antigen levels, and the medical history of diabetes mellitus, chronic cholecystitis, and pancreatitis were also collected.

Results

Malignant IPMNs were detected in 31.6% of 117 patients with lesions in the pancreatic head-neck and 20.9% of 67 patients with lesions in the pancreatic body-tail. In MPD-involved IPMNs, malignancy was observed in 54.1% of patients with lesions in the pancreatic head-neck and 30.8% of patients with lesions in the pancreatic body-tail (p < 0.05). The cutoff value of MPD diameter for malignancy was 6.5 mm for lesions in the head-neck and 7.7 mm for lesions in the body-tail in all type of IPMNs. In MPD-involved IPMNs, the threshold was 8.2 mm for lesion in pancreatic head-neck and 7.7 mm for lesions in the body-tail. Multivariate analysis confirmed that MPD diameter ≥ 6.5 mm (pancreatic head-neck) and MPD diameter ≥ 7.7 mm (pancreatic body-tail) were independent predictors of malignancy (p < 0.05). Similar results were observed in MPD-involved IPMNs using 8.2 mm as a threshold.

Conclusion

The thresholds of the dilated MPD may be associated with IPMNs locations. Thresholds of 6.5 mm for lesions in the head-neck and 7.7 mm for lesions in the body-tail were observed. For MPD-involved IPMNs alone, threshold for lesions in the head-neck was close to that in the body-tail.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02577-3.

A Case of a gastropancreatic fistula in the setting of intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasms (IPMN) are mucin producing tumors which arise from epithelial cells of the main pancreatic duct, pancreatic branch ducts, or both. They are characterized by mucin-producing columnar cells, papillary ductal proliferation, cyst formation, and varying degrees of dysplasia. IPMNs are classified as main duct or branch duct based upon the pancreatic duct anatomy which the IPMN is arising from. Additionally, they can be classified based on their histologic subtypes, which carry varying associations with dysplasia and/or malignancy. Many patients have incidentally identified IPMNs, which are asymptomatic. However, patients may also present with pancreatitis, elevation of liver enzymes, dilation of the pancreatic duct or bile duct as well as distention of the ampullary pancreatic orifice(s), due to impaction and obstruction with mucus. This is known as an endoscopically visualized “fish eye” sign. Patients may also develop exocrine and endocrine pancreatic insufficiency and maldigestion. Some studies also suggest that patients with IPMNs may also be at increased risk for gastric, colorectal, biliary, renal cell, and thyroid malignancies. Rarely, IPMNs can be complicated by fistulation between the main pancreatic duct and neighboring organs. Herein, we present an unusual case of simultaneous fistulation to both the gastric body and the duodenum.

Indications to total pancreatectomy for positive neck margin after partial pancreatectomy: a review of a slippery ground

The extension of a partial pancreatectomy up to total pancreatectomy because of positive neck margin examined at intraoperative frozen section (IFS) analysis is an accepted procedure in modern pancreatic surgery with good accuracy. The goal of this practice is to improve the rate of radical (R0) resection in malignant tumors, mainly pancreatic ductal adenocarcinoma (PDAC), and to completely resect pre-invasive neoplasms such as intraductal papillary mucinous neoplasms (IPMNs). In the setting of IPMNs there is a consensus for pancreatic re-resection when high-grade dysplasia and invasive cancer are present at the neck margin. The presence of denudation is another indication for further resection in IPMNs. The role of IFS analysis in the management of pancreatic cancer is more debated. The presence of a positive intraoperative transection margin can be considered the surrogate of a biologically aggressive disease associated with a poorer prognosis. There are conflicting data regarding possible advantages of pancreatic re-resection up to total pancreatectomy, and the lack of randomized trials comparing different strategies does not offer a definitive answer. The goal of this review is to provide an up-to-date overview of the role IFS analysis of pancreatic margin and of pancreatic re-resection up to total pancreatectomy considering different pancreatic tumors.