Comprehensive Characterization of Intraductal Oncocytic Papillary Neoplasm of the Pancreas: A Systematic and Critical Review.

Intraductal oncocytic papillary neoplasm (IOPN) of the pancreas is a recently recognized pancreatic tumor. Here, we aimed to determine its most essential features with the systematic review tool. PubMed, Scopus, and Embase were searched for studies reporting data on pancreatic IOPN. The clinicopathologic, immunohistochemical, and molecular data were extracted and summarized. Then, a comparative analysis of the molecular alterations of IOPN with those of pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasm from reference cohorts (including The Cancer Genome Atlas) was conducted. The key findings from 414 IOPNs were as follows: 1) The male-to-female ratio was 1.5:1. Pancreatic head was the most common site (131/237; 55.3%), but a diffuse tumor extension involving more than one pancreatic segment was described in about 1 out of 5 cases (49/237; 20.6%). The mean size was 45.5 mm. An associated invasive carcinoma was present in 50% of cases (168/336). In those cases, most tumors were pT1 or pT2 and pN0 (>80%), and vascular invasion was uncommon (20.6%). Regarding survival, more than 90% of patients were alive after surgical resection. 2) Immunohistochemical and molecular features were as follows. The most commonly expressed mucins were MUC5AC (110/112; 98.2%) and MUC6 (78/84; 92.8%). Compared with pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasm, the classic pancreatic drivers KRAS, TP53, CDKN2A, SMAD4, and GNAS were less altered in IOPN (P < .01). Moreover, fusions involving PRKACA or PRKACB gene were detected in all of the 68 cases examined, with PRKACB::ATP1B1 being the most common (27/68 cases; 39.7%). These genomic events emerged as an entity-defining molecular alteration of IOPN (P < .01). Thus, such fusions represent a promising biomarker for diagnostic purposes. Recent evidence also suggests their role in influencing the acquisition of oncocytic morphology. IOPN is a distinct pancreatic neoplasm with specific clinicopathologic and molecular features. Considering the clinical or prognostic implications, its recognition is essential for pathologists and, ultimately, patients' management.

Efficacy and Toxicity Analysis of mFOLFIRINOX in High-Grade Gastroenteropancreatic Neuroendocrine Neoplasms.

BACKGROUND: High-grade neuroendocrine neoplasms (NENs) comprise both well-differentiated grade 3 neuroendocrine tumors (G3 NETs) and poorly differentiated neuroendocrine carcinomas (NECs). Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) nearly always include poorly differentiated NEC as the neuroendocrine component. The efficacy and safety of frontline mFOLFIRINOX chemotherapy has never been investigated in patients with high-grade NENs. PATIENTS AND METHODS: We conducted a multi-institutional retrospective analysis of patients with advanced high-grade NEN of the gastroenteropancreatic tract or of unknown origin seen between February 2016 and April 2023 who received treatment with frontline mFOLFIRINOX. RESULTS: A total of 35 patients were included (G3 NETs: n=2; NECs: n=25; MiNENs: n=8; stage III: n=5; stage IV: n=30). The objective response rate was 77% (complete response: 3%; partial response: 74%). Median progression-free survival was 12 months (95% CI, 9.2-16.2 months) and median overall survival was 20.6 months (95% CI, 17.2-30.6 months). No significant differences in efficacy were seen according to primary site, histopathology, and Ki-67 proliferative index. All 5 patients with stage III disease who received mFOLFIRINOX obtained an objective response and underwent radical surgery or definitive radiotherapy with curative intent, with a recurrence rate of 40%. Grade 3 or 4 adverse events were observed in 43% of patients (mainly neutropenia and diarrhea). Females were at significantly increased risk of developing severe toxicities. CONCLUSIONS: mFOLFIRINOX shows antitumor activity against high-grade NENs. Well-designed, prospective clinical trials are needed to assess the efficacy of mFOLFIRINOX in both the neoadjuvant and metastatic settings.

Ultrasound-derived fat fraction for detection of hepatic steatosis and quantification of liver fat content.

PURPOSE: To compare ultrasound (US) and US-derived fat fraction (UDFF) with magnetic resonance proton density fat fraction (MRI-PDFF) for the detection of hepatic steatosis and quantification of liver fat content. MATERIALS AND METHODS: Between October and December 2022, 149 patients scheduled for an abdominal MRI agreed to participate in this study and underwent MRI-PDFF, US and UDFF. Inclusion criteria were: (a) no chronic liver disease or jaundice; (b) no MRI motion artifacts; (c) adequate liver examination at US. Exclusion criteria were: (a) alcohol abuse, chronic hepatitis, cirrhosis, or jaundice; (b) MRI artifacts or insufficient US examination. The median of 10 MRI-PDFF and UDFF measurements in the right hepatic lobe was analyzed. UDFF and MRI-PDFF were compared by Bland-Altman difference plot and Pearson's test. Sensitivity, specificity, positive and negative predictive values, accuracy, and area under the receiver-operator curve (AUC-ROC) of US and UDFF were calculated using an MRI-PDFF cut-off value of 5%. p values ≤ 0.05 were statistically significant. RESULTS: 122 patients were included (61 men, mean age 60 years, standard deviation 15 years). The median MRI-PDFF value was 4.1% (interquartile range 2.9-6); 37.7% patients had a median MRI-PDFF value ≥ 5%. UDFF and MRI-PDFF had high agreement (p = 0.11) and positive correlation (⍴ = 0.81, p < 0.001). UDFF had a higher diagnostic value than US for the detection of steatosis, with AUC-ROCs of 0.75 (95% CI 0.65, 0.84) and 0.53 (95% CI 0.42, 0.64), respectively. CONCLUSIONS: UDFF reliably quantifies liver fat content and improves the diagnostic value of US for the detection of hepatic steatosis.

US-Guided Percutaneous Radiofrequency Ablation of Locally Advanced Pancreatic Adenocarcinoma: A 5-Year High-Volume Center Experience.

PURPOSE: The aim of this study was to investigate the safety and effectiveness of percutaneous radiofrequency ablation (RFA) in locally advanced pancreatic cancer (LAPC) of the pancreatic body by assessing the overall survival of patients and evaluating the effects of the procedure in the clinical and radiological follow-up. MATERIALS AND METHODS: Patients with unresectable LAPC after failed chemoradiotherapy for at least six months were retrospectively included. Percutaneous RFA was performed after a preliminary ultrasound (US) feasibility evaluation. Contrast-enhanced computed tomography (CT) and CA 19.9 sampling were performed before and 24 hours and 30 days after the procedure to evaluate the effects of the ablation. Patients were followed-up after discharge considering the two main endpoints: procedure-related complications and death. RESULTS: 35 patients were included, 5 were excluded. All patients underwent RFA with no procedure-related complications reported. The mean size of tumors was 49 mm before treatment. The mean dimension of the ablated necrotic zone was 32 mm, with a mean extension of 65 % compared to the whole tumor size. Tumor density was statistically reduced one day after the procedure (p < 0.001). The mean CA 19.9 levels before and 24 hours and 30 days after the procedure were 285.8 U/mL, 635.2 U/mL, and 336.0 U/mL, respectively, with a decrease or stability at the 30-day evaluation in 80 % of cases. The mean survival was 310 (65-718) days. CONCLUSION: Percutaneous RFA of LAPC is a feasible technique in patients who cannot undergo surgery, with great debulking effects and a very low complication rate.

A case of acute bilateral iodine-induced submandibular sialadenitis: Ultrasound findings.

Acute sialadenitis is a rare adverse reaction to iodine-based contrast agents. Ultrasound (US) is usually the preferred imaging method to evaluate the salivary glands; along with clinical and anamnestic data, US allows the diagnosis of contrast-induced sialadenitis. We present a case of acute bilateral submandibular sialadenitis induced by intravenous administration of iodine-based contrast media for a contrast-enhanced computed tomography scan diagnosed by US.

Liver metastases in pancreatic ductal adenocarcinoma: a predictive model based on CT texture analysis.

PURPOSE: To develop a predictive model for liver metastases in patients with pancreatic ductal adenocarcinoma (PDAC) based on textural features of the primary tumor extracted by computed tomography (CT) images. MATERIALS AND METHODS: Patients with a pathologically proved PDAC who underwent CT between December 2020 and January 2022 were retrospectively identified. Treatment-naïve patients were included. Sex, age, tumor size, vascular infiltration and 39 arterial and portal phase textural features were analyzed. The variables significantly correlated to tumor size according to the Pearson's product-moment correlation test were excluded from analysis; the remaining variables were compared between metastatic (M +) and non-metastatic (M-) patients using Fisher's or Mann-Whitney test. The features with a significant difference between groups were entered into a binomial logistic regression test to develop a predictive model for liver metastases. RESULTS: This study included 220 patients. Eight variables (tumor size, arterial HU_MAX, arterial GLRLM_LRLGE, arterial GLZLM_SZHGE, arterial GLZLM_LZLGE, portal GLCM_CORRELATION, portal GLRLM_LRLGE, and portal GLZLM_SZHGE) were significantly different between groups. The logistic regression model was statistically significant (χ2 = 81.6, p < .001) and correctly classified 80.9% of cases. Sensitivity, specificity, positive and negative predictive values of the model were 58.6%, 91.3%, 75.9% and 82.5%, respectively. The area under the ROC curve of the model was 0.850 (95% CI, 0.793-0.907). Tumor size, arterial HU_MAX, arterial GLZLM_SZHGE and portal GLCM_CORRELATION were significant predictors of the likelihood of liver metastases, with odds ratios of 1.1, 0.9, 1, and 1.49, respectively. CONCLUSIONS: CT texture analysis of PDAC can identify features that may predict the likelihood of liver metastases.

Magnetic resonance (MR) for mural nodule detection studying Intraductal papillary mucinous neoplasms (IPMN) of pancreas: Imaging-pathologic correlation.

PURPOSE: Magnetic Resonance (MR) is recommended to diagnose Intraductal Papillary Mucinous Neoplasms (IPMN) and in the follow-up of borderline lesions. The purpose of this work is to evaluate the diagnostic accuracy of dynamic MR with Diffusion Weighted Imaging (DWI) in the identification of mural nodules of pancreatic IPMN by using pathological analysis as gold standard. MATERIALS AND METHODS: Ninety-one preoperative MR with histopathological diagnosis of IPMN were reviewed by two radiologists. Presence, number and size of mural nodule, signal intensity of the nodule on T1-weighted imaging (T1-WI) after contrast medium administration and on DWI. Inter-observer agreement was evaluated. RESULTS: Significant correlation (p < 0.0001) were found for presence of nodules > 5 mm on MR and pathological specimen, size and number of mural nodules evaluated on pathological review and degree of dysplasia, size and number of mural nodules evaluated on MR and tumoral dysplasia, presence of nodule > 5 mm with enhancement after contrast medium administration and hyperintensity on DWI and degree of dysplasia. Interobserver agreement was moderate for the presence of mural nodule (K = 0.56), for the presence of high signal intensity on DWI (K = 0.57) and enhancement of mural nodule (K = 0.58). Apparent Diffusion Coefficient (ADC) map histogram analysis showed a correlation between Entropy of the entire cystic lesion and the degree of dysplasia (p < 0.034). CONCLUSIONS: MR with dynamic and DWI sequences was an accurate method for the identification of ≥ 5 mm solid nodules of the IPMNs and correlate with the lesion malignancy. Entropy, calculated from the histogram analysis of the IPMN ADC map, correlated with the lesion dysplasia.

Impact of coronavirus disease 2019 (COVID-19) emergency on Italian radiologists: a national survey.

OBJECTIVES: To perform an online survey aimed at evaluating the impact of COVID-19 on Italian radiology departments. METHODS: We launched a survey composed of 25 questions about how COVID-19 has changed the safety and organization of daily activity in Italian radiology units. RESULTS: A total of 2136/10,564 (20.2%) radiologists of the Italian Society of Medical and Interventional Radiology participated. Two-thirds performed at least one diagnostic/interventional procedure on COVID-19 patients. The 88.1% reported a reduction in the elective imaging volumes, with US, mammography, and MRI having shown the greater decrease (41.1%, 23.9%, and 21.1%, respectively). In 69.6% of cases, institutions had trouble getting personal protective equipment (PPE), especially public hospitals and southern institutions. Less than 30% of participants were subjected to RT-PCR swab test, although 81.5% believed that it should be done on all health workers and 70% suggested it as the most important measure to improve safety at work. Slightly more than half of participants declared to work safely and felt to be adequately protected by their institutions. Up to 20% of northern participants were redeployed to clinical services. The first imaging examination performed by admitted COVID-19 patients was chest radiography in 76.3% of cases. Almost half of participants reported that less than 30% of health workers were infected in their radiology department, with higher rates in northern regions and public institutions. CONCLUSIONS: This snapshot of the current situation in Italian radiology departments could be used to harmonize the organization of working activity in order to safely and effectively face this pandemic. KEY POINTS: • More than two-thirds of institutions had trouble getting PPE for health workers, with public hospitals and southern institutions that presented more procurement problems • A substantial drop of imaging volumes was observed in the vast majority of Italian radiology departments, mostly due to the decrease of ultrasound, mammography, and MRI, especially in private practice were working activity was stopped in 13.3% of institutions • RT-PCR swab to health workers was reported as the most suggested measure by Italian radiologists to improve safety at work, as more than 80% of them believed that it should be performed to all health workers, although less than 30% were subjected to this test.

The Evolution of Surgical Strategies for Pancreatic Neuroendocrine Tumors (Pan-NENs): Time-trend and Outcome Analysis From 587 Consecutive Resections at a High-volume Institution.

OBJECTIVE: The objective of the present analysis is 2-fold: first, to define the evolution of time trends on the surgical approach to pancreatic neuroendocrine neoplasms (Pan-NENs); second, to perform a complete analysis of the predictors of oncologic outcome. BACKGROUND: Reflecting their rarity and heterogeneity, Pan-NENs represent a clinical dilemma. In particular, there is a scarcity of data regarding their long-term follow-up after surgical resection. METHODS: From the Institutional Pan-NEN database, 587 resected cases from 1990 to 2015 were extracted. The time span was arbitrarily divided into 3 discrete clusters enabling a balanced comparison between patient groups. Analyses for predictors of recurrence and survival were performed, together with conditional survival analyses. RESULTS: Among the 587 resected Pan-NENs, 75% were nonfunctioning tumors, and 5% were syndrome-associated tumors. The mean age was 54 years (±14 years), and 51% of the patients were female. The median tumor size was 20 mm (range 4 to 140), 62% were G1, 32% were G2, and 4% were G3 tumors. Time trends analysis revealed that the number of resected Pan-NENs constantly increased, while the size (from 25 to 20 mm) and G1 proportion (from 65% to 49%) decreased during the study period. After a mean follow-up of 75 months, recurrence analysis revealed that nonfunctioning tumors, tumor grade, N1 status, and vascular invasion were all independent predictors of recurrence. Regardless of size, G1 nonfunctioning tumors with no nodal involvement and vascular invasion had a negligible risk of recurrence at 5 years. CONCLUSIONS: Pan-NENs have been increasingly diagnosed and resected during the last 3 decades, revealing reliable predictors of outcome. Functioning and nodal status, tumor grade, and vascular invasion accurately predict survival and recurrence with resulting implications for patient follow-up.

Patterns of Recurrence after Resection for Pancreatic Neuroendocrine Tumors: Who, When, and Where?

BACKGROUND/AIMS: Pancreatic neuroendocrine tumors (pan-NENs) represent an increasingly common indication for pancreatic resection, but there are few data regarding possible recurrence after surgery. The aim of the study was to describe the frequency, timing, and patterns of recurrence after resection for pan-NENs with consequent implications for postoperative follow-up. METHODS: We performed a retrospective analysis of pan-NENs resected between 1990 and 2015 at The Pancreas Institute, University of Verona Hospital Trust. Predictors of recurrence were assessed. Survival analysis was conducted using the Kaplan-Meier and conditional survival (CS) methods. RESULTS: The cohort consisted of 487 patients with a median follow-up of 71 months. Recurrence developed in 12.3%: 54 (11.1%) liver metastases, 11 (2.3%) local recurrence, 10 (2.1%) nodal recurrence, and 8 (1.6%) metastases in other organs. Thirty-one (6.4%) died due to disease recurrence. Size > 21 mm, G3 grade, nodal metastasis, and vascular infiltration were independent predictors of overall recurrence. Recurrence occurred either during the first year of follow-up (n = 9), or after 10 years (n = 4). CS analysis revealed that nonfunctioning G1 pan-NEN ≤20 mm without nodal metastasis or vascular invasion had a negligible risk of developing recurrence. In the present series, after 5 years of follow-up without developing recurrence, tumor recurrence occurred only in the form of liver metastases. CONCLUSIONS: Recurrence of pan-NENs is rare and is predicted by tumor size, nodal metastasis, grading, and vascular invasion. Patients with G1 pan-NEN without nodal metastasis and vascular invasion may be considered cured by surgery. After 5 years without recurrence, follow-up should focus on excluding the development of liver metastases.

Solid Pseudopapillary Neoplasms of the Pancreas: Clinicopathologic and Radiologic Features According to Size.

OBJECTIVE. The purpose of this study was to retrospectively analyze and correlate clinicopathologic and radiologic features of resected solid pseudopapillary neoplasms of the pancreas according to their size. MATERIALS AND METHODS. Clinicopathologic and radiologic features of 106 resected solid pseudopapillary neoplasms of the pancreas over a 20-year period were retrospectively analyzed. Tumors were divided into three groups according to their size (≤ 30 mm, 31-50 mm, and ≥ 51 mm). Clinicopathologic and radiologic features were compared among groups using Kruskal-Wallis and Fisher exact tests. RESULTS. Forty-one tumors that were 30 mm or smaller, 30 tumors between 31 and 50 mm, and 35 tumors that were 51 mm or larger were included. Preoperative MRI of 76 patients and CT of 40 patients were examined. Patients with tumors that were 30 mm or smaller were significantly older than the other groups of patients (p = 0.038). Large tumors (31-50 and ≥ 51 mm) were more frequently located in the pancreatic body or tail (p = 0.008). Most tumors had well-defined margins (87.7%) and a mixed solid and cystic appearance (54.7%) at imaging; tumors that were 30 mm or smaller were more frequently entirely solid (p = 0.028). At histologic analysis, 13 tumors had at least one feature of malignancy; nodal and liver metastases were found in one patient (0.9%). No significant differences between groups were found regarding the presence of malignant histologic features (p = 0.932). The rate of incorrect preoperative diagnosis was higher in tumors 30 mm or smaller, albeit without significant differences between groups (p = 0.561). CONCLUSION. Malignancy in solid pseudopapillary neoplasms is not correlated with tumor size; tumors that are 30 mm or smaller may present atypical imaging features, which may overlap those of other solid tumors of the pancreas.

Screening/surveillance programs for pancreatic cancer in familial high-risk individuals: A systematic review and proportion meta-analysis of screening results.

BACKGROUND/OBJECTIVES: Screening/surveillance programs for pancreatic cancer (PC) in familial high-risk individuals (FPC-HRI) have been widely reported, but their merits remain unclear. The data reported so far are heterogeneous-especially in terms of screening yield. We performed a systematic review and meta-analysis of currently available data coming from screening/surveillance programs to evaluate the proportion of screening goal achievement (SGA), overall surgery and unnecessary surgery. METHODS: We searched MEDLINE, Embase, PubMed and the Cochrane Library database from January 2000 to December 2016to identify studies reporting results of screening/surveillance programs including cohorts of FPC-HRI. The main outcome measures were weighted proportion of SGA, overall surgery, and unnecessary surgery among the FPC-HRI cohort, using a random effects model. SGA was defined as any diagnosis of resectable PC, PanIN3, or high-grade dysplasia intraductal papillary mucinous neoplasm (HGD-IPMN). Unnecessary surgery was defined as any other final pathology. RESULTS: In a meta-analysis of 16 studies reporting on 1551 FPC-HRI cases, 30 subjects (1.82%), received a diagnosis of PC, PanIN3 or HGD-IPMNs. The pooled proportion of SGA was 1.4%(95% CI 0.8-2, p < 0.001, I2 = 0%). The pooled proportion of overall surgery was 6%(95% CI 4.1-7.9, p < 0.001, I2 = 60.91%). The pooled proportion of unnecessary surgery was 68.1%(95% CI 59.5-76.7, p < 0.001, I2 = 4.05%); 105 subjects (6.3%) received surgery, and the overall number of diagnoses from non-malignant specimens was 156 (1.5 lesion/subject). CONCLUSIONS: The weighted proportion of SGA of screening/surveillance programs published thus far is excellent. However, the probability of receiving surgery during the screening/surveillance program is non-negligible, and unnecessary surgery is a potential negative outcome.

Are Cystic Pancreatic Neuroendocrine Tumors an Indolent Entity Results from a Single-Center Surgical Series.

INTRODUCTION: Cystic pancreatic neuroendocrine tumors (CPanNETs) represent an uncommon variant of pancreatic neuroendocrine tumors (PanNETs). Due to their rarity, there is a lack of knowledge with regard to clinical features and postoperative outcome. METHODS: The prospectively maintained surgical database of a high-volume institution was queried, and 46 resected CPanNETs were detected from 1988 to 2015. Clinical, demographic, and pathological features and survival outcomes of CPanNETs were described and matched with a population of 92 solid PanNETs (SPanNETs) for comparison. RESULTS: CPanNETs accounted for 7.8% of the overall number of resected PanNETs (46/587). CPanNETs were mostly sporadic (n = 42, 91%) and nonfunctioning (39%). Two functioning CPanNETs were detected (4.3%), and they were 2 gastrinomas. The median tumor diameter was 30 mm (range 10-120). All tumors were well differentiated, with 38 (82.6%) G1 and 8 (17.4%) G2 tumors. Overall, no CPanNET showed a Ki-67 >5%. A correct preoperative diagnosis of a CPanNET was made in half of the cases. After a median follow-up of >70 months, the 5- and 10-year overall survival of resected CPanNETs was 93.8 and 62.5%, respectively, compared to 92.7 and 84.6% for SPanNETs (p > 0.05). The 5- and 10-year disease-free survival rates were 94.5 and 88.2% for CPanNETs and 81.8 and 78.9% for SPanNETs, respectively (p > 0.05). CONCLUSION: In the setting of a surgical cohort, CPanNETs are rare, nonfunctional, and well-differentiated neoplasms. After surgical resection, they share the excellent outcome of their well-differentiated solid counterparts for both survival and recurrence.

Can histogram analysis of MR images predict aggressiveness in pancreatic neuroendocrine tumors?

OBJECTIVES: To evaluate MRI derived whole-tumour histogram analysis parameters in predicting pancreatic neuroendocrine neoplasm (panNEN) grade and aggressiveness. METHODS: Pre-operative MR of 42 consecutive patients with panNEN >1 cm were retrospectively analysed. T1-/T2-weighted images and ADC maps were analysed. Histogram-derived parameters were compared to histopathological features using the Mann-Whitney U test. Diagnostic accuracy was assessed by ROC-AUC analysis; sensitivity and specificity were assessed for each histogram parameter. RESULTS: ADCentropy was significantly higher in G2-3 tumours with ROC-AUC 0.757; sensitivity and specificity were 83.3 % (95 % CI: 61.2-94.5) and 61.1 % (95 % CI: 36.1-81.7). ADCkurtosis was higher in panNENs with vascular involvement, nodal and hepatic metastases (p= .008, .021 and .008; ROC-AUC= 0.820, 0.709 and 0.820); sensitivity and specificity were: 85.7/74.3 % (95 % CI: 42-99.2 /56.4-86.9), 36.8/96.5 % (95 % CI: 17.2-61.4 /76-99.8) and 100/62.8 % (95 % CI: 56.1-100/44.9-78.1). No significant differences between groups were found for other histogram-derived parameters (p >.05). CONCLUSIONS: Whole-tumour histogram analysis of ADC maps may be helpful in predicting tumour grade, vascular involvement, nodal and liver metastases in panNENs. ADCentropy and ADCkurtosis are the most accurate parameters for identification of panNENs with malignant behaviour. KEY POINTS: • Whole-tumour ADC histogram analysis can predict aggressiveness in pancreatic neuroendocrine neoplasms. • ADC entropy and kurtosis are higher in aggressive tumours. • ADC histogram analysis can quantify tumour diffusion heterogeneity. • Non-invasive quantification of tumour heterogeneity can provide adjunctive information for prognostication.

Vanishing Pancreatic Cysts during Follow-Up: Another Step Towards De-Emphasizing Cyst Size as a Major Clinical Predictor of Malignancy.

INTRODUCTION: In the management of pancreatic cystic neoplasms (PCN), size plays a crucial role as the expression of disease progression. While many evidences regarding the natural history of growing pancreatic cysts exist, almost no data are available regarding cysts with a reduction in size. METHODS: Radiological and clinical data from patients of the dedicated pancreatic cysts outpatient clinic of the Department of General and Pancreatic Surgery, University of Verona Hospital were retrospectively reviewed. Patients diagnosed with PCNs reducing in size during follow-up were reviewed. RESULTS: From a total of 3,146 patients, we identified 12 (0.38%) vanishing/reducing cysts without a history of pancreatitis. Most of them were presumed IPMN (66.6%). The median follow-up was 69 months and the median cyst's size 30 mm (range 10-49). Most of the patients (75%) experienced a reduction in cyst size (median reduction of 8 mm, range 6-22) after a median time of 12 months (range 6-63), 3 patients experienced a complete disappearance of the cyst. CONCLUSION: Cyst size reduction during follow-up is a rare phenomenon of unknown explanation. It adds to the debate regarding the role of size as a clinical predictor whenever a definite diagnosis of a PCN cannot be reached.

Prevent Pancreatic Fistula after Pancreatoduodenectomy: Possible Role of Ultrasound Elastography.

BACKGROUND: The purpose of the study is to evaluate the utility of acoustic radiation force impulse (ARFI) on pancreatic tissue as a preoperative predictor of postoperative pancreatic fistula (POPF). Studied patients underwent exclusively to pancreaticoduodenectomy (PD) surgery. METHODS: Shear wave velocity of pancreas was measured using ARFI in 71 patients scheduled for PD. An intraoperative pancreas palpation was made by surgeons. A postoperative clinical evaluation to detect occurrence of POPF was performed. Sensitivity, specificity, positive and negative predictive values together with the accuracy of the method were investigated. RESULTS: Incidence of fistula observed in 17 patients with soft pancreas was approximately 53% vs. 47% without fistula. Percentage of patients without fistula was higher (66%) among 24 patients with medium parenchymal texture values, and was even higher (69%) in 26 patients with hard pancreas. Comparing ARFI and intraoperative pancreatic palpation, low wave velocity values (≤1.40 m/s) match 60% with soft parenchyma assessed by palpation and high values (>2 m/s) match 59% with hard pancreas on palpation. CONCLUSIONS: This study shows that ARFI elastography may be clinically useful as a preoperative predictor of pancreatic fistula following PD.

Digital Subtraction of Magnetic Resonance Images Improves Detection and Characterization of Pancreatic Neuroendocrine Neoplasms.

OBJECTIVE: The aim of this study was to evaluate the usefulness of digital image subtraction of contrast-enhanced magnetic resonance (MR) images for detection and characterization of pancreatic neuroendocrine neoplasms (PanNENs). METHODS: Magnetic resonance examinations of 50 histologically verified PanNENs were retrospectively evaluated by 2 radiologists; 50 ductal adenocarcinomas were included as a control group. Late arterial phase images and correspondent subtracted images were analyzed. Tumor detectability on a subjective 3-point scale and contrast-to-noise ratios were compared across sequences using paired Student t tests. Tumor signal intensity was compared between sequences using χ or Fisher exact tests. RESULTS: Subjective conspicuity and contrast-to-noise ratios of PanNENs were significantly higher on subtracted images compared with correspondent late arterial phase images (P < 0.001 and P = 0.002). The rate of clearly hyperenhancing PanNENs was higher on subtracted images compared with arterial phase images (76% vs 36%). CONCLUSIONS: Digital image subtraction improves tumor conspicuity and allows better characterization of PanNENs compared with late arterial phase images.

Acoustic radiation force impulse with shear wave speed quantification of pancreatic masses: A prospective study.

BACKGROUND: Acoustic Radiation Force Impulse (ARFI) is a new ultrasound technique that evaluates mechanical properties of tissues. To evaluate the use of ARFI with shear waves speed quantification for pancreatic masses characterization during the ultrasound examination. METHODS: 123 pancreatic lesions were prospectively evaluated. Median shear waves speeds were compared with Mann-Whitney U test. Two reading methods were applied for the characterization of adenocarcinoma: more than one measurement above the top shear waves speed (SWS) value. Two reading methods were applied to diagnose mucinous lesion: at least 2 (method 1) or 3 (method 2) numerical measurements. Sensitivity, specificity, positive and negative predictive values and accuracy of each reading method were calculated. Forty volunteers were included for normal ARFI values. RESULTS: In the adenocarcinoma group median SWS value was 2.74 m/s. In the volunteers group the median SWS value was 1.17 m/s. Significant difference between SWS median values of adenocarcinoma and normal pancreas was found (P < 0.05). For the diagnosis of pancreatic solid masses if more than one measurement is above the top SWS value of 4.00 m/s results in the study, the diagnosis of ductal adenocarcinoma is highly specific with specificity and PPV of 100%. Good sensitivity (73.3%) and specificity (83.3%) were obtained for the characterization of mucinous cystic lesions. CONCLUSIONS: Acoustic Radiation Force Impulse imaging could help in the non-invasive characterization of solid and cystic lesions of the pancreas during a conventional US examination.