Branch Duct Type Intraductal Papillary Mucinous Neoplasm Research Articles

Effectiveness of contrast-enhanced endoscopic ultrasound for detecting mural nodules in intraductal papillary mucinous neoplasm of the pancreas and for making therapeutic decisions.

Background and Objectives:There have been few studies to date evaluating the effectiveness of contrast-enhanced endoscopic ultrasound (CE-EUS) for detecting mural nodules in patients with branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN) of the pancreas. We aim to evaluate the effectiveness of CE-EUS for detecting mural nodules in BD-IPMN.Patients and Methods:Of the 427 BD-IPMN patients, 21 patients (4.9%) in whom the presence of mural nodules was suggested by CE computed tomography (CT) or magnetic resonance imaging (MRI), or in whom the presence of nodule-like lesions as shown by fundamental EUS, were examined by CE-EUS.Results:The mean diameter of cystic lesions was 29.8 ± 12.8 mm. The mean diameter of mural nodules was 9.5 ± 5.7 mm. BD-IPMN was detected in the pancreatic head in 16 cases, pancreatic body in 2 cases, and pancreatic tail in 3 cases. The mean follow-up period was 17.2 ± 11.9 months. The detection rates of mural nodule-like lesions in BD-IPMN patients on CT, MRI, and fundamental EUS were 36.8%, 63.2%, and 100%, respectively. The detection rates of true mural nodules in BD-IPMN patients on CT, MRI, and fundamental EUS were 85.7%, 71.4%, and 100%, respectively. The echo levels of mural nodule-like lesions on fundamental EUS were hyperechoic in 6 patients, isoechoic in 9 patients, and hypoechoic in 6 patients. The final diagnosis was mucus lumps in 14 patients and mural nodules in 7 patients. The contrast patterns observed were avascular, isovascular, and hypervascular in 14, 3, and 4 patients, respectively. No patients showed a hypovascular pattern. Fourteen patients showing an avascular pattern were diagnosed as having mucus lumps, and they were able to avoid surgical resection. Of the 7 patients who were diagnosed as having mural nodules, 5 underwent surgical resection. The pathological findings were adenocarcinoma in 2 patients and adenoma in 3 patients. Of the 3 adenoma patients, fundamental EUS demonstrated a hypoechoic area in 1 patient and an isoechoic area in 2 patients. Of the 2 adenocarcinoma patients, 1 each showed a hypoechoic area and a hyperechoic area. It was difficult to distinguish between patients with adenoma and patients with adenocarcinoma using the echo levels obtained from fundamental EUS.Conclusions:CE-EUS may be useful for avoiding the overdiagnosis of BD-IPMN with mural nodule-like lesions. However, it has difficulty in distinguishing between clearly benign and malignant lesions in BD-IPMN.

Su1474 Outcome of Over 1 Year Follow up Cases in Multifocal Branch Duct Type IPMN

Introduction: The presence of mural nodule (MN) is an important factor for the management of branch duct type intraductal papillary mucinous neoplasm (BD-IPMN). International consensus guidelines 2012 recommend clinical follow-up to BD-IPMN without MNs. However, it is not clear whether BD-IPMNs with MNs need surgical treatment regardless of the height of MNs. Aim: To compare the pathological and follow-up outcomes between BDIPMNs with MNs ≤6mm in height (MN+) and those without MNs (MN-). Methods: The patients who were diagnosed as BD-IPMNs with MNs ≤6mm or without MNs since April 2004 to December 2013 were retrospectively analyzed. Inclusion criteria were the obtaining of contrast enhanced CT and EUS at initial diagnosis, and surgical resection in our center or follow-up with annual/semi-annual CT/MRCP. The cyst size and main pancreatic duct (MPD) diameter were measured by CT/MRCP, while MN height was measured by EUS. Tumor progression during follow-up was defined as follows; increased cyst size ≥10mm; increased MPD diameter ≥10mm; new development of MN or increased MN height ≥2mm. Evaluation points: 1) pathological diagnosis of resected BD-IPMN, 2) follow-up outcomes Results: Among 656 patients of BD-IPMNs diagnosed in our center, MN height was evaluated as less than or equal to 6mm in 511(78%; MN+ 50, MN352). After initial diagnosis, 17(3%; MN+ 8, MN9) of them underwent immediate resection and 385(75%; MN+ 42, MN343) of them received regular follow-up, who were eligible for this analysis. The median cyst size and MPD diameter were 20(10-70) mm and 3(2-12) mm, respectively. The median height of MNs in MN+ were 3(1-6) mm. 1) The pathological diagnosis of the patients with MNwere all low/intermediate-grade dysplasia (LID), while those of the patients with MN+ were LID in 5, high-grade dysplasia (HD) in 2, and invasive carcinoma (IC) in 1. There were no significant differences in pathological diagnosis between MN+ and MN(p=0.17, chi-square test). 2) During a median follow-up period of 3.4(0.5-10.6) years, 49(13%; MN+ 9, MN40) patients exhibited tumor progression. The 5-years cumulative tumor progression rate was higher in MN+ than those in MN(MN+ 19% vs MN9%; p<0.01, Log-rank test). Among 49 patients with tumor progression, 11(22%; MN+ 4, MN7) patients underwent surgical resection, whose pathological diagnosis were LID in 6(MN+ 2, MN4), HD in 3(MN+ 1, MN2), and IC with minimal invasion in 2(MN+ 1, MN1). The other 38 patients continued to be followed during a median period of 0.6(0.0-4.2) years. Meanwhile, concomitant pancreatic ductal adenocarcinoma (PDAC) was appeared in 9(2%; MN+ 1, MN8) patients. Conclusion: Although tumor progression rate was higher, BD-IPMN with MNs ≤6mm in height on EUS could be managed conservatively. However, careful attention should be paid to the development of PDAC during follow-up.

Su1471 Clinical Observation Is Possible for Branch Duct Type Intraductal Papillary Mucinous Neoplasms With Mural Nodules ≤6mm

Introduction: The presence of mural nodule (MN) is an important factor for the management of branch duct type intraductal papillary mucinous neoplasm (BD-IPMN). International consensus guidelines 2012 recommend clinical follow-up to BD-IPMN without MNs. However, it is not clear whether BD-IPMNs with MNs need surgical treatment regardless of the height of MNs. Aim: To compare the pathological and follow-up outcomes between BDIPMNs with MNs ≤6mm in height (MN+) and those without MNs (MN-). Methods: The patients who were diagnosed as BD-IPMNs with MNs ≤6mm or without MNs since April 2004 to December 2013 were retrospectively analyzed. Inclusion criteria were the obtaining of contrast enhanced CT and EUS at initial diagnosis, and surgical resection in our center or follow-up with annual/semi-annual CT/MRCP. The cyst size and main pancreatic duct (MPD) diameter were measured by CT/MRCP, while MN height was measured by EUS. Tumor progression during follow-up was defined as follows; increased cyst size ≥10mm; increased MPD diameter ≥10mm; new development of MN or increased MN height ≥2mm. Evaluation points: 1) pathological diagnosis of resected BD-IPMN, 2) follow-up outcomes Results: Among 656 patients of BD-IPMNs diagnosed in our center, MN height was evaluated as less than or equal to 6mm in 511(78%; MN+ 50, MN352). After initial diagnosis, 17(3%; MN+ 8, MN9) of them underwent immediate resection and 385(75%; MN+ 42, MN343) of them received regular follow-up, who were eligible for this analysis. The median cyst size and MPD diameter were 20(10-70) mm and 3(2-12) mm, respectively. The median height of MNs in MN+ were 3(1-6) mm. 1) The pathological diagnosis of the patients with MNwere all low/intermediate-grade dysplasia (LID), while those of the patients with MN+ were LID in 5, high-grade dysplasia (HD) in 2, and invasive carcinoma (IC) in 1. There were no significant differences in pathological diagnosis between MN+ and MN(p=0.17, chi-square test). 2) During a median follow-up period of 3.4(0.5-10.6) years, 49(13%; MN+ 9, MN40) patients exhibited tumor progression. The 5-years cumulative tumor progression rate was higher in MN+ than those in MN(MN+ 19% vs MN9%; p<0.01, Log-rank test). Among 49 patients with tumor progression, 11(22%; MN+ 4, MN7) patients underwent surgical resection, whose pathological diagnosis were LID in 6(MN+ 2, MN4), HD in 3(MN+ 1, MN2), and IC with minimal invasion in 2(MN+ 1, MN1). The other 38 patients continued to be followed during a median period of 0.6(0.0-4.2) years. Meanwhile, concomitant pancreatic ductal adenocarcinoma (PDAC) was appeared in 9(2%; MN+ 1, MN8) patients. Conclusion: Although tumor progression rate was higher, BD-IPMN with MNs ≤6mm in height on EUS could be managed conservatively. However, careful attention should be paid to the development of PDAC during follow-up.

Su1473 Risk Factor for Appearance of Invasive Carcinoma During Follow Up in Branch Duct Type IPMN

Su1473 Risk Factor for Appearance of Invasive Carcinoma During Follow Up in Branch Duct Type IPMN

Predictors of early stages of histological progression of branch duct IPMN.

An appropriate timing for surgical resection of branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN) to achieve sufficient postoperative survival is still unknown. Of 80 patients with histologically proven IPMNs, 61 patients who had BD-IPMN without pancreatic cancer concomitant with IPMN were enrolled in this study. We divided BD-IPMN into four groups according to disease progression: low to intermediate grade of dysplasia (LGD/IGD-IPMN), high grade of dysplasia (HGD-IPMN), minimally invasive IPMN (MI-IPMN: T1a), and invasive IPMN (IN-IPMN: ≥T1b). Indicators of surgical resection were investigated on the basis of pathological findings and postoperative prognosis. Postoperative survival was distinctly worse for patients with IN-IPMN than for patients with MI-IPMN, HGD-IPMN, and LGD/IGD-IPMN. Postoperative disease-specific 5-year survival rate was 100 % in patients with IN-IPMN, HGD-IPMN, and LGD/IGD-IPMN, by contrast, 40 % in patients with IN-IPMN. The presence of two of the three factors (pancreatitis, serum carbohydrate antigen [CA] 19-9 levels >13 U/mL, and mural nodules) could distinguish HGD-IPMN from LGD/IGD-IPMN with a sensitivity of 92.9 %, specificity of 90.2 %, positive predictive value of 76.5 %, negative predictive value of 97.4 %, and accuracy of 90.9 %. To manage patients with BD-IPMN and achieve a good postoperative prognosis, surgical resection should be performed before progression to IN-IPMN.

Surgical treatment and prognosis of 96 cases of intraductal papillary mucinous neoplasms of the pancreas: A retrospective cohort study

Introduction: The indications, the extent and type of surgery for intraductal papillary mucinous neoplasm (IPMN) are still controversial. This study aimed to investigate clinical manifestation, individualized surgical treatment, and prognosis of IPMN of pancreas. Methods: The clinical data of 96 IPMN cases treated in our hospital between January 2006 and December 2013 were retrospectively analyzed. Among the 96 patients (58 male and 38 female), 46 were main-duct type, 29 were branch-duct type, 21 were mixed type. Pancreatectomy was performed on 78 cases, including pancreaticoduodenectomy on 43 patients, distal pancreatectomy on 25, segmental pancreatectomy on 6, and total pancreatectomy on 4. A regular follow-up without surgical treatment was performed on 18 cases with asymptomatic side branch IPMN less than 3 cm in diameter. Results: The overall postoperative morbidity rate was 33.3%, and there was no perioperative mortality. 46 cases were non-invasive IPMN, 32 cases were invasive IPMN including 14 cases with lymph node metastasis. The five-year survival rate for patients with non-invasive and invasive carcinomas was 96.2% and 35.2%, respectively. The prognosis of invasive cases with lymph node metastasis was significantly worse than those without lymph node metastasis. No progression was found during the follow-up in 18 asymptomatic small branch duct type IPMN patients. Conclusion: IPMN has a relative good prognosis. Main duct type and mixed type IPMN have a higher malignant potential, and should receive surgical treatment. Patients of branch duct type IPMN with lesion <3 cm in diameter and without clinical manifestations can be managed with close follow-up.

Pancreatic main-duct involvement in branch-duct IPMNs: an underestimated risk.

This study aimed to analyze a large single-center population of resected intraductal papillary mucinous neoplasms (IPMN) of the pancreas with respect to risk factors of malignant transformation. There is international consensus that main-duct (MD) as well as mixed-type IPMNs should be treated surgically due to a high risk of malignancy. In contrast, there is an ongoing controversy about surgery of branch-duct type IPMN (BD-IPMN). All consecutive patients who underwent surgery for IPMN between January 2004 and December 2012 were included. Clinical characteristics and preoperative imaging were correlated with histopathological features. A total of 512 patients underwent pancreatic surgery and had a histological proof of IPMN. According to preoperative imaging, 74 patients had MD-IPMN (14%), 205 mixed-type (40%), and 233 suspected BD-IPMN (46%). On histopathology, 162 of 512 patients revealed low-grade, 105 moderate, and 52 high-grade dysplasia. One hundred ninety-three IPMN patients (38%) suffered from invasive carcinoma. Among invasive IPMNs, the majority (58%) were mixed-type lesions according to preoperative imaging. Of 141 Sendai negative BD-IPMNs, a malignancy rate of 18% (high-grade dysplasia and invasive carcinoma) was found. Most interesting, 29% of suspected BD-IPMNs (67/233) revealed histological involvement of the main pancreatic duct not evident in preoperative imaging. All subtypes of IPMNs display a relevant risk for malignant transformation. By abdominal imaging, many IPMNs are misclassified as BD-IPMNs but reveal mixed-type lesions in histopathology. Because currently available preoperative diagnostics are not sufficient to reliably diagnose BD-IPMNs, surgical resection for suspected small branch-duct IPMN should be considered in patients fit for surgery.

Prediction of Malignancy With Endoscopic Ultrasonography in Patients With Branch Duct–Type Intraductal Papillary Mucinous Neoplasm

We evaluated the accuracy of a new endoscopic ultrasonography (EUS) scoring system to predict malignancy in branch duct-type intraductal papillary mucinous neoplasms (BD-IPMNs). We performed a retrospective multicenter study of patients who underwent EUS within 3 months before surgery and were diagnosed as having BD-IPMNs by postoperative pathologies at 8 hospitals in Korea from August 2002 to December 2011. To predict the malignancy, we applied the EUS scoring system consisting of pancreatic cyst size, height of mural nodules, main duct dilatation, septal thickening, and patulous orifice. We evaluated the diagnostic accuracy of the new EUS scoring system and compared it with previous individual risk factors. Eighty-four patients (male-to-female ratio, 55:29; mean [SD] age, 64.7 [7.1] years) had 68 benign BD-IPMNs and 16 malignant intraductal papillary mucinous neoplasms. The EUS scoring system showed 75.0% sensitivity and 94.1% specificity at 7 points. This system (area under the curve, 0.939; 95% confidence interval, 0.884-0.994) resulted in a more accurate prediction than the previous known other factors including Sendai criteria, dilatation of ducts, size of the cyst, and presence of septal thickening and mural nodules. The EUS scoring system predicted BD-IPMN malignancy more accurately than the Sendai criteria and individual risk factors.

Risk factors for malignancy in branched-type intraductal papillary mucinous neoplasms of the pancreas during the follow-up period.

The international consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas were revised in 2012 Tanaka (Pancreatology 12(3):183-197, 2012), making the indications for operation less aggressive. Therefore, the number of branch duct-type IPMN (BD-IPMN) patients requiring follow-up care is expected to increase in the future. The aim of this study was to identify risk factors for malignancy in BD-IPMN patients during the follow-up period. This study included 47 BD-IPMN patients without a mural nodule (MN) at the time of initial diagnosis and who subsequently underwent resection after a follow-up period of more than 3 months. Data for the patients were reviewed retrospectively, and the clinicopathological factors were investigated. In a univariate analysis, age (≧ 65 years), an increase in the main pancreatic duct (MPD) diameter, the MPD diameter at resection (≧ 5 mm), and the occurrence of MN were significantly associated with malignancy. The occurrence of MN was the only significant factor in a multivariate analysis. In addition, 7 of the 17 patients (41.2 %) who only exhibited an increase in the cyst diameter during the follow-up period were diagnosed as having malignancies. All 6 patients who exhibited an increase in the cyst diameter of 100 % or more were diagnosed as having carcinoma. During the follow-up period, the incidence of malignancy was higher among patients with BD-IPMNs and the occurrence of MN, an increase in the MPD diameter, or an increase ratio of 100 % or more in cyst diameter than the others; resection was recommended for these patients.

Surgical outcomes of multifocal branch duct intraductal papillary mucinous neoplasms of pancreas.

Backgrounds/AimsAppropriate management for multifocal branch duct type intraductal papillary mucinous neoplasms (BD-IPMNs) of the pancreas is still controversial. This study was intended to reveal surgical outcomes of surgical resection for multifocal BD-IPMNs, with BD-IPMNs in the remnant pancreas.MethodsBetween January 1995 and December 2013, 699 patients underwent the pancreatic resection due to IPMN of pancreas in our institution. Among them, 37 patients showed multifocal BD-IPMNs. After excluding patients who had BD-IPMNs completely resected, medical records of 22 patients with remained BD-IPMNs in the remnant pancreas were retrospectively reviewed.ResultsMean patient age was 65±6.4 years. Types of surgery included central pancreatectomy (n=1), distal pancreatectomy (n=14), and standard pylorus-preserving pancreaticoduodenectomy (n=7). Specimen pathology showed that IPMN was either at low/intermediate-grade dysplasia (n=17) or at high-grade dysplasia (n=2). Three patients had IPMN associated with invasive carcinoma. Their mean follow-up period was 40.4 months. During follow-up, one mortality occurred 35.2 months after the operation which was not associated with IPMN. There was no clinically significant disease progression or recurrence of IPMN in the remnant pancreas during the follow-up period.ConclusionsOur results support that we can safely preserve the pancreas parenchyma with multifocal BD-IPMNs. Benign-looking multifocal BD-IPMNs in the remnant pancreas do not affect the survival of patients.

Imaging pitfalls of pancreatic serous cystic neoplasm and its potential mimickers.

The aim of this article is to clarify diagnostic pitfalls of pancreatic serous cystic neoplasm (SCN) that may result in erroneous characterization. Usual and unusual imaging findings of SCN as well as potential SCN mimickers are presented. The diagnostic key of SCN is to look for a cluster of microcysts (honeycomb pattern), which may not be always found in the center. Fibrosis in SCN may be mistaken for a mural nodule of intraductal papillary mucinous neoplasm (IPMN). The absence of cyst wall enhancement may be helpful to distinguish SCN from mucinous cystic neoplasm. However, oligocystic SCN and branch duct type IPMN may morphologically overlap. In addition, solid serous adenoma, an extremely rare variant of SCN, is difficult to distinguish from neuroendocrine tumor.

A Case of Acute Recurrent Pancreatitis Caused by Branch Duct Type IPMN and Ampulla of Vater Adenoma with High Grade Dysplasia

Acute pancreatitis is an inflammatory disease that can extend to extra-pancreatic tissues and distant organs. Detecting the underlying cause is important because it helps provide an appropriate treatment plan and improve prognosis. An underlying cause cannot be identified after initial evaluation in 10-30% of patients with acute pancreatitis, and they are diagnosed with idiopathic acute pancreatitis. Here, we report a case of a 77-year-old woman with acute recurrent pancreatitis caused by a branch duct-type intraductal papillary mucinous neoplasm (IPMN) and an ampulla of Vater adenoma. Abdominal computed tomography and magnetic resonance cholangiopancreatography revealed only IPMN. However, endoscopic retrograde cholangiopancreatography revealed a mucosal abnormality of the ampulla of Vater. The mucosal abnormality was documented to be an ampulla of Vater adenoma with high-grade dysplasia. (Korean J Med 2014;87:579-584)

O2–023 - The Clinical Features of Branch Duct Type Ipmns of the Pancreas with Classification of Histological Subtypes

Background: Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are divided into two types, the main duct type and the branch duct type. Generally, the branch duct type grows slowly and has a good prognosis compared to the main branch type. According to International consensus guidelines for the management of IPMN, if lesion is < 10mm in size, the interval between follow-up examination would appear reasonable to be every 2-3 years. However, there were reportedly some cases of the branch duct type IPMNs were known to show rapidly growing and progression to malignancy. Recently, IPMNs of the pancreas are classified into 4 types-gastric (G type), intestinal (I type), pancreatobiliary (PB type), and oncocytic (O type) on the basis of their morphology and immunohistochemistry. The G types and I types are known to have less malignant potential than that of the PB type, and invasive carcinomas derived from two types is known to be less invasive and slower growing than those derived from the PB type. But we have had no minute examination of the clinical features of each type. So, we investigated the resected cases of 22 patients with branch duct type IPMNs, which were classified into 4 types and compared with the speed of cystic lesion with IPMNs and the frequency of invasive carcinoma of each type. Methods: We classified the 22 patients with branch duct type IPMNs resected between January 2005 and February 2012 in our institutes, into 4 types on the basis of their morphology and immunohistochemistry, and revealed the speed of cystic lesion with IPMNs and the frequency of invasive carcinoma of each type. Results: Fifteen patients (68%) were G type, 4 patients (18%) were I type, 3 patients (14%) were PB type. There is no patient of O type. Their median age was 73.2 years (range 57-84), 77 years (range 64-84), and 71.3 years (range 59-79), respectively. The frequency of invasive adenocarcinoma derived from IPMN was 2/15 (13%), 1/4 (25%), and 3/3 (100%) respectively. The growing speed of cystic lesion of patients who could be observed over 1 year (mean ± SD mm/year) was 3.0 ± 0.9, 3.54 ± 1.6, and 15.2 ± 9.2 respectively (p < 0.05). Conclusion: PB type showed rapid growing and high frequent progression to malignancy compared to G and I type. Our findings suggest that PB type should be followed for shorter period.

Surgical indication based on malignant predictors for the patients with branch duct type IPMN

Surgical indication based on malignant predictors for the patients with branch duct type IPMN

Results of a surveillance protocol for pancreatic BD-IPMNs

s / Pancreatology Methods: We retrospectively analysed the clinicopathological factors of 184 patients (114 men, median age 63 yr) undergoing resection for branch duct type IPMNs at 14 tertiary hospitals in Korea, to identify malignant predictors of this neoplasm. Malignant IPMNs were defined as those with noninvasive and invasive intraductal papillary mucinous carcinoma. Results: Among 184 patients with branch duct type IPMN, eighty-two patients had adenoma, 78 borderline, 10 noninvasive carcinoma, and 14 invasive carcinoma. Malignant pancreatic tumor distinct from IPMN developed in 7 patients (3.8%). We found significant factors for malignancy in these patients in a univariate analysis; cyst size > 3 cm (P 3 cm, and main pancreatic duct dilatation were independent factors associated with malignancy. By receiver operating characteristics curve analysis, a tumor size of > 3 cm was the most valuable cutoff point. In patients (n1⁄4110) who had endoscopic ultrasonography (EUS), an increase in the size of mural nodule with EUS significantly affected the sensitivity to predict malignancy. The area under the curve for the size of predictors for malignant branch duct IPMNs was 0.7998, and the sensitivity and specificity were 72.7% and 78.8%, respectively, when the cutoff value was set at 7.5 mm. Conclusions: We identified 3 useful predictive factors for malignancy in branch duct type IPMN; a mural nodule size, cyst size > 3 cm, and main pancreatic duct diameter. The size of mural nodule with EUS showed high predictative ability.

Tu1230 Malignant Predictors for Branch Duct Type IPMN

Tu1230 Malignant Predictors for Branch Duct Type IPMN

Invasive carcinoma derived from branch duct-type IPMN may be a more aggressive neoplasm than that derived from main duct-type IPMN

The present study aimed to evaluate the long-term follow-up results of patients with intraductal papillary mucinous neoplasm (IPMN) and to estimate the degree of IPMN malignancy based on pathological and molecular features of resected specimens. The detection rate of IPMN has increased over the last decade; however, the management of this neoplasm remains controversial. This is particularly so for branch duct-type IPMN, which carries a high potential for malignancy and risk of recurrence. We retrospectively reviewed a single institution’s prospective pancreatic resection database to identify IPMN patients who underwent pancreatectomy with curative intent. The clinicopathological variables of 100 patients resected for IPMN were analyzed with a detailed review of histopathological results (borderline lesions, non-invasive carcinoma and invasive carcinoma) to determine the grade of IPMN malignancy based on transforming growth factor (TGF)-β/SMAD4 signaling. The incidence of malignant change was significantly higher in patients with main duct-type IPMN (69.7%) compared with branch duct-type IPMN cases (17.9%). However, patients with an invasive carcinoma had a significantly worse outcome if it was derived from branch duct-type IPMN compared with those derived from main duct-type IPMN, and TGF-β mRNA expression was significantly increased in the former patient group. Immunohistochemistry also showed higher numbers of SMAD4-positive cells in patients with carcinoma derived from branch duct-type IPMN. Our results demonstrated that invasive carcinoma derived from branch duct-type IPMN is more aggressive than that derived from main duct-type IPMN, once invasive morphological change takes place. Determining TGF-β and/or SMAD4 status at initial diagnosis may be useful for stratifying IPMN patients into treatment regimens.

Pancreatic duct lavage cytology with the cell block method for discriminating benign and malignant branch-duct type intraductal papillary mucinous neoplasms

Differentiation between benign and malignant branch-duct type intraductal papillary mucinous neoplasms (IPMNs) remains challenging. To examine the usefulness of pancreatic duct lavage cytology with cell block method for discriminating benign and malignant branch-duct type IPMNs. Between December 2007 and April 2011, patients with branch-duct type IPMNs having mural nodules on EUS were examined by pancreatic duct lavage cytology by using the cell block method. Cell block sections underwent hematoxylin and eosin staining and mucin immunostainings (MUCs 1, 2, 5AC, and 6). Single-center, prospective study. Academic medical center. The sensitivity and specificity of cytology were assessed. The agreement between cytological and histological results for MUC was also examined. Cytology with this method was investigated in 44 patients. Cell block diagnosis was cancer positive (class V or IV) in 11 patients and negative (classes I, II, III, and noninformative) in 33. The sensitivity, specificity, and positive and negative predictive values of this method were 92%, 100%, 100%, and 97%, respectively. The cytological and histological results of MUCs 1, 2, 5AC, and 6 agreed in 88% (15/17), 94% (16/17), 88% (15/17), and 100% (17/17), respectively. Single center and small number of patients. Pancreatic duct lavage cytology with the cell block method may be useful to differentiate between benign and malignant IPMNs preoperatively and as well as to determine their mucin type.

Synchronous pancreatic solid pseudopapillary neoplasm and intraductal papillary mucinous neoplasm

Solid pseudopapillary neoplasm (SPN) is a rare and low-grade malignant pancreatic neoplasm composed of poorly cohesive monomorphic neoplastic cells forming solid and pseudopapillary structures with frequent hemorrhagic-cystic degeneration. Intraductal papillary mucinous neoplasm (IPMN) is a pancreatic exocrine tumor composed of intraductal papillary growth of mucin containing neoplastic cells in the main pancreatic duct or its major branches. In the case presented here, a 53-year-old, Japanese man was found to have multiple cystic lesions and dilatation of the main pancreatic duct in the neck of the pancreas. Histological examination revealed a main-duct and branch-duct type IPMN, of the gastric-type, involving the neck of the pancreas, associated with a 0.5 cm SPN in the caudal side of the IPMN. We diagnosed this case as synchronous SPN and IPMN. As far as we know, only one other case of synchronous SPN and IPMN has been reported. Both the present case and the previously reported case showed abnormal nuclear expression of β-catenin in SPN, whereas IPMN showed no abnormal nuclear expression. These results suggest that β-catenin abnormality is not a common pathogenetic factor of synchronous SPN and IPMN.

Localized type 1 autoimmune pancreatitis superimposed upon preexisting intraductal papillary mucinous neoplasms

A 70-year-old woman was found to have 2 cystic lesions in the head of the pancreas on abdominal ultrasonography during a routine medical examination. Endoscopic ultrasonography (EUS) and magnetic resonance cholangiopancreatography showed multilocular cysts in the head of the pancreas without dilation of the main pancreatic duct. The patient was followed-up semiannually with imaging studies for suspected branch duct-type intraductal papillary mucinous neoplasm (IPMN). At 3 years after initial presentation, hypoechoic lesions were observed around each pancreatic cyst by EUS. Diffusion-weighted imaging showed high-intensity regions corresponding to these lesions. Therefore, a diagnosis of invasive carcinoma derived from IPMN could not be excluded, and subtotal stomach-preserving pancreaticoduodenectomy was performed. The macroscopic examination of the surgical specimen showed whitish solid masses in the head of the pancreas, with multilocular cysts within each mass. Microscopically, each solid mass consisted of inflammatory cells such as lymphocytes and plasma cells. Furthermore, immunochemical staining revealed immunoglobulin G4-positive cells, and many obliterating phlebitides were observed. The cysts consisted of mucus-producing epithelial cells and showed a papillary growth pattern. Based on these findings, we diagnosed multiple localized type 1 autoimmune pancreatitis occurring only in the vicinity of the branch duct-type IPMN.