Dilatation of the main pancreatic duct of unknown origin: causes and risk factors of pre-malignancy or malignancy.

INTRODUCTION: A dilatation of the main pancreatic duct (MPD) is mainly due to obstructive causes (pancreatic tumor, chronic pancreatitis) or intraductal papillary mucinous neoplasm (IPMN). This study aims to assess the risk of pre-malignancy or malignancy in case of MPD dilatation with no visible mass nor obstructive calcification on computed tomography scan (CT-scan) in a population operated for it. PATIENTS AND METHODS: All patients operated on from November 2015 to December 2019 in our center for a significant dilatation of the MPD without visible obstructive cause on CT-scan were included. Preoperative work-up included at least CT-scan, magnetic resonance imaging (MRI), and endoscopic ultrasonography (EUS). Primary endpoint was the final pathological diagnosis. Secondary endpoints were predictive factors of malignancy. RESULTS: 101 patients were included, mean age 68 years-old. Final pathological data were pancreatic adenocarcinoma (n = 2), IPMN with high-grade dysplasia (n = 37), high-grade Pancreatic Intraepithelial Neoplasia (PanIN) (n = 2) (total of pre-malignant or malignant lesions: n = 41), neuroendocrine tumor (n = 6), IPMN with low-grade dysplasia (n = 45), low-grade PanIN (n = 5), chronic pancreatitis (n = 3), and benign stenosis (n = 1). On preoperative explorations, the median diameter of MPD was 7 mm [3-35]. MRI and/or EUS showed intraductal material, nodule, or cyst in 22, 32, and 52 patients, respectively; 22 patients without nodule visible on MRI or EUS had still a pre-malignant or malignant lesion. In multivariate analysis, predictive factors for pre-malignancy or malignancy were symptoms before surgery (p = 0.01), MPD dilatation without downstream stenosis (p = 0.046), and the presence of nodule (p = 0.009). CONCLUSION: A dilatation of the MPD without detectable mass or obstructive calcification on CT-scan was associated with a pre-malignant or malignant lesion in 41 patients. Symptoms before surgery, MPD dilatation without duct narrowing, and the presence of nodules on MRI/EUS were associated with the risk of  pre-malignancy or malignancy.

MRI is useful to suggest and exclude malignancy in mucinous cystic neoplasms of the pancreas.

OBJECTIVES: To evaluate the value of MRI in differentiating benign (b-MCN) and malignant (m-MCN) MCN. European guidelines suggest that certain mucinous cystic neoplasms (MCN) of the pancreas can be conservatively managed. METHODS: A retrospective single-center study of consecutive patients with resected MCN. MRIs were independently reviewed by two readers blinded to the pathological results. The authors compared b-MCN (i.e., mucinous-cystadenoma comprising high-grade dysplasia (HGD)) and m-MCN (i.e., cystadenocarcinoma). RESULTS: Sixty-three patients (62 women [98%]) with 63 MCN (6 m-MCN, 2 HGD) were included. m-MCN tumors had a tendency to be larger than b-MCN (median 86 [25-103] vs. 45 [17-130] mm, p = .055). The combination of signal heterogeneity on T2-weighted imaging, wall thickness ≥ 5 mm, the presence of mural nodules ≥ 9 mm, and enhancing septa had an area under the ROC curve of 0.97 (95% CI 0.91-1.00) for the diagnosis of m-MCN. A total of 24 (37%), 20 (32%), 10 (16%), 5 (8%), and 4 (6%) out of 63 MCNs showed 0, 1, 2, 3, and 4 of these features, respectively. The corresponding rate of m-MCN was 0%, 0%, 10%, 20%, and 100%, respectively, with a good-to-excellent inter-reader agreement. Patterns with a high NPV for m-MCN included an absence of enhancing septa or walls (NPV 97% and 100%, respectively), wall thickness < 3 mm (NPV 100%), and no mural nodules (NPV 100%). CONCLUSIONS: A combination of 4 imaging features suggests malignant MCN on MRI. On the other hand, visualization of a thin non-enhancing wall with no mural nodules suggests benign MCN. KEY POINTS: • A heterogenous signal on T2-weighted MRI, a ≥ 5-mm-thick wall, mural nodules ≥ 9 mm, and/or enhancing septa suggest malignant MCNs. • A thin non-enhancing wall with no mural nodules suggests benign MCNs. • MRI should be performed in the pre-therapeutic evaluation of MCN to help determine the therapeutic strategy in these patients.

Are recist criteria adequate in assessing the response to therapy in metastatic NEN?

Response to therapy criteria, known as RECIST (Response Evaluation Criteria in Solid Tumours), are widely used to evaluate neuroendocrine tumours (NET) metastatic to the liver, under treatment. RECIST criteria does not take in account many various distinct features such as tumour growth, secretory capacity and anatomical localisation with wide variation in clinical and biological presentation of different NETs. Key features of RECIST includes definitions of the minimal size of measurable lesions, instructions on how many lesions to measure and follow, and the use of unidimensional, rather than bidimensional, measures for overall evaluation of tumour burden. These measures are currently done with computed tomography (CT) or Magnetic Resonance Imaging (MRI). RECIST criteria are accurate in assessing tumour progression but sometimes inaccurate in assessing tumour response after locoregional therapy or under molecular targeted therapy, tumour vessels being part of the target of such treatments. There is poor correlation between a so called tumour necrosis and conventional methods of response assessment, which poses questions of how best to quantify efficacy of these targeted therapies. Variations in tumour density with computed tomography (CT) could theoretically be associated with tumour necrosis. This hypothesis has been studied proposing alternative CT criteria of response evaluation in metastatic digestive NET treated with targeted therapy. If preliminary results upon the poor relationship between density measured with CT (derived from CHOI criteria) evolution curves at CT and PFS are confirmed by further studies, showing that the correlation between density changing and response to non-targeted treatment is weak, the use of contrast injection, will probably be not mandatory to enable appropriate evaluation.

French reconnection: A conservative pancreato-enteric reconnection for disconnected pancreatic duct syndrome.

BACKGROUND/OBJECTIVES: Disconnectedpancreatic duct syndrome (DPDS), a severe complication of acute necrotizing pancreatitis (ANP), may require surgery, usually by distal splenopancreatectomy, thus increasing the risk of diabetes. We describe a new technique reconnecting the distal pancreas to the digestive tract. METHODS: This technique was proposed after failure of non-surgical treatment and at least 3 months after the onset of ANP in non-diabetic or non-insulin dependent diabetic patients with a distal pancreas of at least 5 cm. The ruptured zone was identified and the distal side was anastomosed to the stomach or the jejunum. RESULTS: From 2013 to June 2019, 36 patients (median age = 49 years) with DPDS underwent a "French reconnection" procedure, indicated for chronic pain/recurrent pancreatitis (n = 35; 97%), persistent pancreatic fistula (n = 33; 91%), or digestive compression/fistulisation (n = 9; 25%). Median preoperative weight loss was 10 kg (4-27), the median number of hospitalisations per patient was 5(1-8) and 24(67%) patients had received endoscopic/percutaneous treatment. Surgery was performed in median 279(90-2000) days after ANP, laparoscopically in 9(25%) patients. The remnant pancreas (median length = 70 mm; range = 50-130) was anastomosed to the stomach (n = 30) or the jejunum (n = 6). There were 13(36%) postoperative grade B/C pancreatic fistulas and 3(10%) bleedings including one death (mortality = 3%). The median hospital stay was 18 (7-121) days. After a median follow-up of 24 (4-53) months, all pancreatic fistulas had healed and the clinical success rate was 91%. Median BMI increased from 22 to 25 kg/m2. In patients with normal pancreatic function, postoperative de novo endocrine and severe exocrine insufficiencies were observed in 4/27 (15%) and 7/22 (32%), respectively. CONCLUSIONS: The "French reconnection" procedure, as an alternative to distal splenopancreatectomy for the treatment of DPDS, provides good control of symptoms and decreases the risk of pancreatic insufficiency.

Diffuse Versus Localized Caroli Disease: A Comparative MRCP Study.

OBJECTIVE. The purpose of this multicenter retrospective study was to assess the MRCP features of Caroli disease (CD). MATERIALS AND METHODS. Sixty-six patients were identified from 2000 to 2019. The inclusion criteria were diagnosis of diffuse or localized CD mentioned in an imaging report, presence of intrahepatic bile duct (IHBD) dilatation, and having undergone an MRCP examination. The exclusion criteria included presence of obstructive proximal biliary stricture and having undergone hepatobiliary surgery other than cholecystectomy. Histopathology records were available for 53 of the 66 (80%) patients. Diffuse and localized diseases were compared by chi-square and t tests and Kaplan-Meier model. RESULTS. Forty-five patients had diffuse bilobar CD ((five pediatric patients [three girls and two boys] with a mean [± SD] age of 8 ± 5 years [range, 1-15 years] and 40 adult patients [26 men and 14 women] with a mean age of 35 ± 11 years [range, 20-62 years]) and 21 patients had localized disease (12 men and 9 women; mean age, 54 ± 14 years). Congenital hepatic fibrosis was found only in patients with diffuse CD (35/45 [78%]), as was a "central dot" sign (15/35 [43%]). IHBD dilatation with both saccular and fusiform features was found in 43 (96%) and the peripheral "funnel-shaped" sign in 41 (91%) of the 45 patients with diffuse CD but in none of the patients with localized disease (p < .001). Intrahepatic biliary calculi were found in all patients with localized disease but in only 16 of the 45 (36%) patients with diffuse CD (p < .001). Left liver atrophy was found in 18 of the 21 (86%) patients with localized disease and in none of the patients with diffuse CD (p < .001). The overall survival rate among patients with diffuse CD was significantly lower than that among patients with localized disease (p = .03). CONCLUSION. Diffuse IHBD dilatation with both saccular and fusiform features associated with the peripheral funnel-shaped sign can be used for the diagnosis of CD on MRCP. Localized IHBD dilatation seems to be mainly related to primary intrahepatic lithiasis.

Correction to: Prediction of pancreatic neuroendocrine tumour grade with MR imaging features: added value of diffusion-weighted imaging.

The original version of this article, published on 19 August 2016, unfortunately contained a mistake.

Unmet Medical Needs in Metastatic Lung and Digestive Neuroendocrine Neoplasms.

Unmet medical needs are not infrequent in oncology, and these needs are usually of higher magnitude in rare cancers. The field of neuroendocrine neoplasms (NENs) has evolved rapidly during the last decade, and, currently, a new WHO classification is being implemented and several treatment options are available in the metastatic setting after the results of prospective phase III clinical trials. However, several questions are still unanswered, and decisions in our daily clinical practice should be made with limited evidence. In the 2016 meeting of the advisory board of the European Neuroendocrine Tumor Society (ENETS), the main unmet medical needs in the metastatic NENs setting were deeply discussed, and several proposals to try to solve them are presented in this article, including biomarkers, imaging, and therapy.

Non-branched microcysts of the pancreas on MR imaging of patients with pancreatic tumors who had pancreatectomy may predict the presence of pancreatic intraepithelial neoplasia (PanIN): a preliminary study.

PURPOSE: To evaluate whether pancreatic parenchymal abnormalities on magnetic resonance imaging (MRI) are associated with pancreatic intraepithelial neoplasia (PanIN) on histology. MATERIALS AND METHODS: Retrospective study approved by institutional review board. One hundred patients (48 men, 52 women; mean age, 53.2 ± 16.29 [SD]) underwent MRI before pancreatectomy for pancreatic tumors analyzed by two independent observers blinded to histopathological results for the presence of non-communicating microcysts and pancreatic atrophy (global or focal) beside tumors. MRI findings were compared to histopathological findings of resected specimens. Interobserver agreement was calculated. The association between parenchymal abnormalities and presence of PanIN was assessed by uni- and multivariate analyses. RESULTS: PanIN was present in 65/100 patients (65%). The presence of microcysts on MRI had a sensitivity of 52.3% (34/65 [95%CI, 51.92-52.70%]), a specificity of 77.1% (27/35 [95%CI, 76.70-77.59]), and accuracy of 61% (61/100 95%CI [50.7-70.6]) for the diagnosis of PanIN while global atrophy had a sensitivity of 24.6% (16/6 [95%CI, 24.28-24.95]) and a specificity of 97.1% (34/35 [95%CI, 96.97-97.32%]). In multivariate analysis, the presence of microcysts (OR, 3.37 [95%CI, 1.3-8.76]) (p = 0.0127) and global atrophy (OR, 9.79 [95%CI, 1.21-79.129]) (p = 0.0324) were identified as independent predictors of the presence of PanIN. The combination of these two findings was observed in 10/65 PanIN patients and not in patients without PanIN (p = 0.013 with an OR of infinity [95%CI, 1.3-infinity]) and was not discriminant for PanIN-3 and lower grade (p = 0.22). Interobserver agreement for the presence of microcysts was excellent (kappa = 0.92), and for the presence of global atrophy, it was good (kappa = 0.73). CONCLUSION: The presence of non-communicating microcysts on pre-operative MRI can be a significant predictor of PanIN in patients with pancreatic tumors. KEY POINTS: • In patients with pancreatic tumors who had partial pancreatectomy, MR non-communicating pancreatic microcysts have a 52.3% sensitivity, a 77.1% specificity, and a 61% accuracy for the presence of PanIN with univariate and with an odds ratio of 3.37 with multivariate analyses. • The association of global atrophy and non-communicating microcysts increases the predictive risk of PanIN.

Routine MRI With DWI Sequences to Detect Liver Metastases in Patients With Potentially Resectable Pancreatic Ductal Carcinoma and Normal Liver CT: A Prospective Multicenter Study.

OBJECTIVE: The purpose of this study was to evaluate the performance of systematic MRI with DWI for the detection of liver metastases (LM) in patients with potentially resectable pancreatic ductal carcinoma and normal liver findings at CT. SUBJECTS AND METHODS: Patients with potentially resectable pancreatic ductal carcinoma and a normal liver at CT were enrolled in a prospective multicenter study between March 2011 and July 2013 and underwent preoperative MRI. The reference standard was pathologic analysis of detected hepatic lesions. RESULTS: A total of 118 patients were enrolled. MRI depicted liver lesions that were not visible at CT in 16 patients. All lesions were visualized both with and without DWI. Lesions were LM in 12 (10.2%) patients and were confirmed in seven patients by preoperative biopsy, four by intraoperative frozen section, and one at 6-month follow-up evaluation after pancreatic resection. All but one liver metastatic lesion diagnosed with MRI were smaller than 10 mm. Four of 118 (3.4%) patients had a false-positive diagnosis of LM at MRI and remained LM free after a follow-up period of 24 months or longer. Three of 102 (2.9%) patients with normal MRI findings had subcapsular LM that were diagnosed intraoperatively. At follow-up, 99 of 118 (83.9%) patients were LM free after a mean of 24 months. The patient-based sensitivity of MRI for the detection of LM was 80.0% (95% CI, 51.9-95.7%); specificity, 96.1% (95% CI, 90.4-98.9%); positive predictive value, 75.0% (95% CI, 47.6-92.7%); and negative predictive value, 97.1% (95% CI, 91.6-99.4%). CONCLUSION: Compared with CT, preoperative MRI improves the detection of LM in patients with potentially resectable pancreatic ductal carcinoma and may change management and the rate of unnecessary laparotomy and pancreatectomy for 10% of patients.

[Imaging of chronic pancreatitis]. / Imagerie de la pancréatite chronique.

Imaging of chronic pancreatitis. Chronic pancreatitis is a combination of imaging pattern: duct abnormalities, with irregularity, enlargement alternating with stenosis, of main pancreatic duct (beading) and enlargement of branch duct (more than 3 thin branch ducts visible); intra ductal or parenchymal calcifications; parenchymal atrophy, global or focal. When CT is typical, no more imaging is needed. On the contrary, MRI with MRCP (2 D one) is necessary to explore doubtful chronic pancreatitis, particularly to find out discrete ductal irregularities. Then pancreas ductal carcinoma could be depicted, particularly with long lasting chronic pancreatitis, and new onset or relapse of pain. The main differential diagnosis with imaging is intra ductal pancreatic mucinous neoplasia (IPMN).

Imagerie de la pancréatite chronique. Le diagnostic de pancréatite chronique repose sur la présence d'anomalies et d'irrégularités de calibre des canaux pancréatiques (principal et secondaires), de calcifications parenchymateuses et/ou intracanalaires, d'une atrophie globale ou localisée. La tomodensitométrie, si elle est typique, suffit au diagnostic. Le protocole d'imagerie par résonance magnétique doit inclure les séquences classiques mais aussi la cholangio-pancréatographie par résonance magnétique 2D qui doit être systématique pour l'exploration du pancréas. Dans un contexte de pancréatite chronique, l'imagerie peut être confrontée à la détection d'un cancer chez un patient dont l'affection évolue depuis de longues années et qui a une récidive des symptômes douloureux, ou à un diagnostic différentiel avec une tumeur intracanalaire papillaire et mucineuse du pancréas (TIPMP) mixte.

Prediction of pancreatic neuroendocrine tumour grade with MR imaging features: added value of diffusion-weighted imaging.

OBJECTIVES: To evaluate the value of MR imaging including diffusion-weighted imaging (DWI) for the grading of pancreatic neuroendocrine tumours (pNET). MATERIAL AND METHODS: Between 2006 and 2014, all resected pNETs with preoperative MR imaging including DWI were included. Tumour grading was based on the 2010 WHO classification. MR imaging features included size, T1-w, and T2-w signal intensity, enhancement pattern, apparent (ADC) and true diffusion (D) coefficients. RESULTS: One hundred and eight pNETs (mean 40 ± 33 mm) were evaluated in 94 patients (48 women, 51 %, mean age 52 ± 12). Fifty-five (51 %), 42 (39 %), and 11 (10 %) tumours were given the following grades (G): G1, G2, and G3. Mean ADC and D values were significantly lower as grade increased (ADC: 2.13 ± 0.70, 1.78 ± 0.72, and 0.86 ± 0.22 10-3 mm2/s, and D: 1.92 ± 0.70, 1.75 ± 0.74, and 0.82 ± 0.19 10-3 mm2/s G1, G2, and G3, all p < 0.001). A higher grade was associated with larger sized tumours (p < 0.001). The AUROC of ADC and D to differentiate G3 and G1-2 were 0.96 ± 0.02 and 0.95 ± 0.02. Optimal cut-off values for the identification of G3 were 1.19 10-3 mm2/s for ADC (sensitivity 100 %, specificity 92 %) and 1.04 10-3 mm2/s for D (sensitivity 82 %, specificity 92 %). CONCLUSION: Morphological/functional MRI features of pNETS depend on tumour grade. DWI is useful for the identification of high-grade tumours. KEY POINTS: • Morphological and functional MRI features of pNETs depend on tumour grade. • Their combination has a high predictive value for grade. • All pNETs should be explored by MR imaging including DWI. • DWI is helpful for identification of high-grade and poorly-differentiated tumours.

Toward a Preoperative Classification of Lymph Node Metastases in Patients with Small Intestinal Neuroendocrine Tumors in the Era of Intestinal-Sparing Surgery.

INTRODUCTION: In patients with small intestinal neuroendocrine tumors (siNETs), surgical resection of the primary tumor and associated mesenteric lymph nodes (LNs) is recommended, but is not well standardized and can be risky in patients with superior mesenteric vessel involvement. OBJECTIVE: We aimed to evaluate the correlation between the length of resected small bowel and the number of removed LNs, and to propose a preoperative morphological classification of siNET-associated LNs. METHODS: The records of patients operated on for siNETs at two expert centers between August 2005 and November 2013 were analyzed. Two specialist radiologists reviewed the preoperative imaging and classified mesenteric LNs into five stages according to their proximity to the trunk and/or branches of the superior mesenteric artery. RESULTS: 72 patients were included. The mean number of removed LNs was 12 ± 15 and the length of removed small intestine was 53 ± 43 cm. No correlation existed between the length of small bowel resection and the number of removed LNs. Overall, 9 (12%), 13 (18%), 36 (50%), 14 (19%) and 0 patients were classified into LN stages 0, I, II, III and IV. The correlation rate between the two observers was 0.98. Patients with LN stage III (hardly resectable) had more removed LNs than those with LN stages 0, I or II (easily removable). CONCLUSION: Optimal lymphadenectomy is not always associated with extended small bowel resection. In the era of small bowel-sparing surgery, the preoperative classification of mesenteric LNs could help to standardize the surgical management of patients with siNETs.

Long-term Prognosis of Resected Pancreatic Neuroendocrine Tumors in von Hippel-Lindau Disease Is Favorable and Not Influenced by Small Tumors Left in Place.

BACKGROUND: Management of pancreatic neuroendocrine tumors (PNETs) associated with von Hippel-Lindau disease (VHL) is challenging because of the malignant potential and difficulty in predicting prognosis. OBJECTIVE: Compare the long-term outcome of resected VHL-PNET and sporadic PNET. METHODS: Data of all patients with VHL (n = 23) operated on for nonmetastatic PNET were reviewed. Patient characteristics and recurrence-free survival rates were compared with those in patients operated on for sporadic PNET, matched for tumor size, stage, and Ki-67 index. RESULTS: Patients in both groups had similar demographic characteristics, except that patients with VHL were younger (36 vs 56 years, P < 0.0001). Median tumor size was 30 mm. Median Ki-67 index was 3% and 4% in the VHL and sporadic groups (P = 0.95), respectively, and lymph node metastases were present in 43% and 30% of cases, respectively (P = 0.45). Sixteen (70%) patients with VHL had multiple PNET; lesions less than 15 mm were left in place in 11 patients. Median postoperative follow-up was 107 months (interquartile range, 57-124 months) and 71 months (interquartile range, 58-131 months) in the VHL and control groups, respectively. Median recurrence-free survival could not have been estimated in the VHL group due to the low number of events (hazard ratio, 5.6; 95% confidence interval, 1.4-22.6; P = 0.013). Five patients with VHL died (3 from VHL-related tumors including 1 from PNET), whereas only one control patient died due to unrelated causes. CONCLUSIONS: The long-term outcome of resected VHL-PNET is better than that of sporadic PNET. PNET less than 15 mm left in place did not progress. A parenchyma-sparing surgical strategy seems appropriate in patients with VHL-PNET, who may develop more life-threatening tumors of other organs.

Parenchyma-sparing pancreatectomy for presumed noninvasive intraductal papillary mucinous neoplasms of the pancreas.

OBJECTIVE: To assess the feasibility and outcomes of parenchyma-sparing pancreatectomy (PSP), including enucleation (EN), resection of uncinate process (RUP), and central pancreatectomy (CP), as an alternative to standard pancreatectomy for presumed noninvasive intraductal papillary and mucinous neoplasms (IPMNs). BACKGROUND: Pancreaticoduodenectomy and distal pancreatectomy are associated with significant perioperative morbidity, a substantial risk of pancreatic insufficiency, and may overtreat noninvasive IPMNs. METHODS: From 1999 to 2011, PSP was attempted in 91 patients with presumed noninvasive IPMNs, after complete preoperative work-up including computed tomography, magnetic resonance imaging, and endoscopic ultrasonography. Intraoperative frozen section examination was routinely performed to assess surgical margins and rule out invasive malignancy. Follow-up included clinical, biochemical, and radiological assessments. RESULTS: Overall PSP was achieved with a feasibility rate of 89% (n = 81), including 44 ENs, 5 RUPs, and 32 CPs. Postoperative mortality rate was 1.3% (n = 1), and overall morbidity was noteworthy (61%; n = 47). Definitive pathological examination confirmed IPMN diagnosis in 95% of patients (n = 77), all except 2 (3%), without invasive component. After a median follow-up of 50 months, both pancreatic endocrine/exocrine functions were preserved in 92% of patients. Ten-year progression-free survival was 76%, and reoperation for recurrence was required in 4% of patients (n = 3). CONCLUSIONS: In selected patients, PSP for presumed noninvasive IPMN in experienced hands is highly feasible and avoids inappropriate standard resections for IPMN-mimicking lesions. Early morbidity is greater than that after standard resections but counterbalanced by preservation of pancreatic endocrine/exocrine functions and a low rate of reoperation for tumor recurrence.

Does tobacco influence the natural history of autoimmune pancreatitis?

UNLABELLED: Tobacco recently appeared as a major independent factor adversely influencing the natural course of alcoholic chronic pancreatitis. However, the role of tobacco in patients with autoimmune pancreatitis (AIP) has never been studied. Type 2 AIP is associated with inflammatory bowel disease, especially ulcerative colitis in which smoking is protective. The aim of our study was to evaluate the influence of smoking on course of AIP. PATIENTS AND METHODS: All consecutive patients followed in our centre for AIP according to ICDC were studied. Tobacco consumption was recorded. A relation between smoking and all event related to AIP was searched for. RESULTS: 96 patients with type 1 (73%) or type 2 (27%) AIP were included; 76% of patients were low smokers (never, ex- or smokers <10 p.y.) and 24% were high smokers (≥10 p.y.). The mean follow-up was 60 months [5-188]. AIP relapse was observed in 26% of patients. At the end-point, smokers ≥10 p.y. presented more frequently diabetes (50% vs 27%, p = 0.04) and imaging pancreatic damages (59% vs 34%, p = 0.02) than low smokers. There was also a non significant tendency to observe more frequently exocrine insufficiency and relapse in smokers ≥10 pack-year. No protective effect of smoking was observed in the subgroup of patients with type 2 AIP and ulcerative colitis. CONCLUSIONS: In patients with AIP, high tobacco intake is associated with the risk of imaging pancreatic damages and with the occurrence of diabetes. Smoking cessation should be recommended.

CT and MR imaging of multilocular acinar cell cystadenoma: comparison with branch duct intraductal papillary mucinous neoplasia (IPMNs).

OBJECTIVES: To describe CT and MR imaging findings of acinar cell cystadenoma (ACC) of the pancreas and to compare them with those of branch duct intraductal papillary mucinous neoplasia (BD-IPMN) to identify distinctive elements. METHODS: Five patients with ACC and the 20 consecutive patients with histologically proven BD-IPMN were retrospectively included. Clinical and biological information was collected and histological data reviewed. CT and MR findings were analysed blinded to pathological diagnosis in order to identify imaging diagnostic criteria of ACC. RESULTS: Patients with ACC were symptomatic in all but one case and were younger than those with BD-IPMN (p = 0.006). Four radiological criteria allowed for differentiating ACC from IPMN: five or more cysts, clustered peripheral small cysts, presence of cyst calcifications and absence of communication with the main pancreatic duct (p < 0.05). Presence of at least two or three of these imaging criteria had a strong diagnostic value for ACC with a sensitivity of 100% and 80% and a specificity of 85% and 100%, respectively. CONCLUSIONS: Preoperative differential diagnosis between ACC and BD-IPMN can be achieved using a combination of four CT and/or MR imaging criteria. Recognition of ACC patients could change patient management and lead to more conservative treatment. KEY POINTS: Four imaging findings are associated with acinar cell cystadenoma (ACC). Imaging could achieve differential diagnosis between ACC and BD-IPMN. Diagnosis on imaging would change patient management and avoid surgical resection.

Ampullary tumors: French Intergroup Clinical Practice Guidelines for diagnosis, treatments and follow-up (TNCD, SNFGE, FFCD, UNICANCER, GERCOR, SFCD, SFED, ACHBT, AFC, SFRO, RENAPE, SNFCP, AFEF, SFP, SFR).

BACKGROUND: Management of ampullary tumors (AT) is challenging because of a low level of scientific evidence. This document is a summary of the French intergroup guidelines regarding the management of AT, either adenoma (AA) or carcinoma (AC), published in July 2023, available on the website of the French Society of Gastroenterology (SNFGE) (www.tncd.org). METHODS: A collaborative work was conducted under the auspices of French medical, endoscopic, oncological and surgical societies involved in the management of AT. Recommendations are based on recent literature review and expert opinions and graded in three categories (A, B, C), according to quality of evidence. RESULTS: Accurate diagnosis of AT requires at least duodenoscopy and EUS. All patients should be discussed in multidisciplinary tumor board before treatment. Surveillance may only be proposed for small AA in familial adenomatous polyposis. For AA, endoscopic papillectomy is the preferred option only if R0 resection can be achieved. When not possible, surgical papillectomy should be considered. For AC beyond pT1a N0, pancreaticoduodenectomy is the procedure of choice. Adjuvant monochemotherapy (gemcitabine, 5FU) may be proposed. For aggressive tumors (pT3/T4, pN+, R1, poorly differentiated AC, pancreatobiliary differentiation) with high risk of recurrence, 6 months polychemotherapy (CAPOX/FOLFOX for the intestinal subtype and mFOLFIRINOX for the pancreatobiliary or the mixed subtype) may be a valid alternative. Clinical and radiological follow up is recommended for 5 years. CONCLUSIONS: These guidelines help to homogenize and highlight unmet needs in the management of AA and AC. Each individual case should be discussed by a multidisciplinary team.

High sensitivity of diffusion-weighted MR imaging for the detection of liver metastases from neuroendocrine tumors: comparison with T2-weighted and dynamic gadolinium-enhanced MR imaging.

PURPOSE: To compare the sensitivity and specificity of diffusion-weighted (DW) magnetic resonance (MR) imaging for identifying liver metastases from neuroendocrine tumor (NET) to those of T2-weighted fast spin-echo (FSE) and three-dimensional dynamic gadolinium-enhanced MR imaging, with surgical and histopathologic findings as the reference standard. MATERIALS AND METHODS: This retrospective study was approved by institutional review board, and informed consent was waived. Fifty-nine patients with NETs (41 patients with 162 liver metastases, and 18 control subjects with no liver metastases) underwent MR imaging that included DW, T2-weighted FSE, and dynamic gadolinium-enhanced MR sequences. Images were retrospectively reviewed by two abdominal radiologists, independently, for the detection and characterization of liver metastases. MR findings were compared with histopathologic and intraoperative ultrasonography findings for metastasis on a lesion-by-lesion basis to determine the sensitivity of each MR sequence alone and combined. Specificity was calculated by using the control population. Interreader agreement for each MR sequence and McNemar test were also calculated. RESULTS: There was excellent agreement between observers 1 and 2 for characterizing liver metastases at per-lesion analysis (κ coefficient: 0.86-1.00). DW MR was more sensitive (observer 1: sensitivity, 71.6% [116 of 162], 95% confidence interval [CI]: 64.2%, 78.0%; observer 2: sensitivity, 71.0% [115 of 162], 95% CI: 63.6%, 77.4%) than T2-weighted FSE (observer 1: sensitivity, 55.6% [90 of 162], 95% CI: 47.9%, 63.0%; observer 2: sensitivity, 55.6% [90 of 162], 95% CI: 47.9%, 63.0%) and dynamic gadolinium-enhanced MR (observer 1: sensitivity, 47.5% [77 of 162], 95% CI: 34.0%, 55.2%; observer 2: sensitivity, 48.1% [78 of 162], 95% CI: 40.6%, 55.8%) (P < .001 for both, McNemar test). The specificity of these sequences ranged from 88.9% to 100% (DW MR vs T2-weighted FSE MR: P > .99, DW MR vs dynamic gadolinium-enhanced MR: P = .61, and T2-weighted FSE MR vs dynamic gadolinium-enhanced MR: P = .61, McNemar test). CONCLUSION: DW MR imaging was more sensitive for the detection and characterization of liver metastases from NETs than T2-weighted FSE and dynamic gadolinium-enhanced MR imaging and should be systematically performed.