Clinical aspects of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) is a spectrum of neoplasia in the pancreatic duct epithelium characterized by cystic dilation of the main and/or branch pancreatic duct. According to the site of involvement IPMNs are classified into three categories, i.e., main duct type, branch duct type, and combined type. Most branch duct IPMNs are benign, whereas the other two types are often malignant. A large size of branch duct IPMN and marked dilation of the main pancreatic duct indicate the presence of adenoma at least. The additional existence of large mural nodules increases the possibility of malignancy in all types. Of recent interest is the relatively high prevalence of synchronous and/or metachronous malignancy in various organs, including the pancreas. The prognosis is favorable after complete resection of benign and noninvasive malignant IPMNs. Malignant IPMNs acquiring aggressiveness after parenchymal invasion necessitate adequate lymph node dissection. On the other hand, asymptomatic branch duct IPMNs without mural nodules can be observed without resection for a considerably long time. This review addresses available data, current understanding, controversy, and future directions.     

Management of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a distinct entity characterized by papillary proliferations of mucin-producing epithelial cells with excessive mucus production and cystic dilatation of the pancreatic ducts. IPMNs have malignant potential and exhibit a broad histologic spectrum, ranging from adenoma to invasive carcinoma. IPMNs are classified into main duct and branch duct types, based on the site of tumor involvement. IPMN patients have a favorable prognosis if appropriately treated. The postoperative 5-year survival rate is nearly 100% for benign tumors and noninvasive carcinoma, and approximately 60% for invasive carcinoma. A main duct type IPMN should be resected. Surgical treatment is indicated for a branch duct IPMN with suspected malignancy (tumor diameter ≥ 30 mm, mural nodules, dilated main pancreatic duct, or positive cytology) or positive symptoms. Malignant IPMNs necessitate lymph node dissection (D1). IPMNs are associated with a high incidence of extrapancreatic malignancies and pancreatic ductal carcinoma.     

Management of intraductal papillary-mucinous neoplasm of the pancreas: treatment strategy based on morphologic classification

GOALS: The aim of this study was to examine and clarify the preoperative markers that are useful for differentiating between benign and malignant lesions of intraductal papillary-mucinous neoplasms (IPMN) of the pancreas, grouped according to morphologic classification. BACKGROUND: There are various stages of pathology in IPMN, ranging from benign to malignant lesions. Although the determination of appropriate treatment guidelines to deal with IPMN is a critical issue, no such guidelines have been established. PATIENTS AND METHODS: One hundred twenty cases of IPMN were classified morphologically into either main or branch duct types. We compared the morphologic classification with histopathologic diagnosis using indicators of malignancy detected by imaging such as main duct diameter, the number and diameter of cysts, and the presence or absence of mural nodules. We also examined the usefulness of pancreatic juice cytology and measurement of telomerase activity as indicators of malignancy. Finally, we performed a survival analysis on the basis of morphologic classification to determine prognosis of IPMN. RESULTS: Whereas a high incidence (64%) of malignant lesions was seen in main duct type IPMN, benign lesions were dominant (80.5%) in branch duct type IPMN. Survival analysis showed that the prognosis was significantly worse in main duct type than in branch duct type IPMN. The lesions were aggravated in all patients with main duct type who did not undergo resection, resulting in death due to progression of the pancreatic lesion. The incidence of mural nodules was a useful indicator in main duct type, whereas main duct diameter and incidence of mural nodules were useful indicators in branch duct type. Although pancreatic juice cytology showed a high accuracy rate with low sensitivity for determining malignancy, measurement of telomerase activity in this juice was very effective for differentiating between benign and malignant lesions. CONCLUSIONS: The incidence of malignant lesions was extremely high in main duct type IPMN, indicating that surgery is required in all these patients. However, to determine whether surgery is indicated in branch duct type IPMN it is necessary to obtain an appropriate image diagnosis focusing on main duct diameter and mural nodules and also to carry out cytology and measurement of telomerase activity in samples of pancreatic juice.     

Optimal management of the branch duct type intraductal papillary mucinous neoplasms of the pancreas

GOALS: To determine the optimal management of the intraductal papillary mucinous neoplasms (IPMNs) according to the morphologic type based on distinguishing between benign and malignant diseases. BACKGROUNDS: IPMNs are increasingly recognized clinicopathologic entity. Extended pancreatic resection with radical lymph node dissection has been recommended for treatment. STUDY: A retrospective clinicopathologic study was carried out of the 57 cases with IPMNs who were treated between 1985 and 2001. Forty-three patients with IPMNs underwent resection, and 14 patients with small IPMNs were observed without resection. RESULTS: Among the 43 resected IPMNs, 25 were benign and 18 were malignant. Malignant tumors were significantly greater in diameter than benign tumors (52.9 vs. 30.2 mm, P< 0.05). All main duct type tumors with mural nodules were malignant. All branch duct type tumors less than 30 mm in diameter and without mural nodules were benign. Twelve branch duct type IPMNs size less than 30 mm were not resected and have not progressed. CONCLUSION: These results suggest that the branch duct type IPMNs less than 30 mm and without mural nodules is benign and might be treatable with limited resection or careful observation.     

胰腺导管内乳头状黏液瘤

胰腺导管内乳头状黏液瘤（IPMN）是由胰腺导管内产生黏液的上皮细胞呈乳头状增殖形成的肿瘤。与经典的胰腺癌相比,IPMN具有低度恶性、生长缓慢、少有侵犯周围组织、淋巴结转移率和再发率低的特点。IPMN根据肿瘤累及的部位可分为主胰管型、分支胰管型和混合型,病理组织特征涵盖从单纯腺瘤到浸润癌等多个亚型,临床表现多样,多种影像学检查手段可显示弥漫性或节段性扩张的主胰管和囊状扩张的分支胰管,ERCP经扩大的乳头获取黏液和胰液,取胰腺导管内皮组织和壁结节供活检均有助于诊断。IPMN确诊后应积极手术,手术切除率高,术后5年生存率高于一般的胰腺癌。本文就其临床表现、分类、病理特征、影像学诊断和治疗等方面做一综述。     

Size of mural nodule as an indicator of surgery for branch duct intraductal papillary mucinous neoplasm of the pancreas during follow-up

Background

A mural nodule is a strong predictive factor for malignancy in branch duct intraductal papillary mucinous neoplasm (IPMN) of the pancreas, but the nodule size has hardly been considered. The aim of this study was to investigate whether a mural nodule of 10?mm was appropriate as an indicator of surgery for IPMN during follow-up.

Methods

The follow-up outcomes of 100 patients who had branch duct IPMN without mural nodules or who had branch duct IPMN with mural nodules of less than 9?mm in a tertiary care setting were investigated retrospectively. The patients underwent abdominal ultrasound (US) every 3?months and additional imaging examinations or cytologic examination of pancreatic juice when necessary. Surgery was recommended to them when a mural nodule developed or when a nodule enlarged and reached 10?mm.

Results

During an average follow-up period of 97?months, branch duct IPMNs developed mural nodules that reached 10?mm in 5 patients (0.62% per year). In one patient the IPMN was revealed to be non-invasive carcinoma by resection, 1 IPMN was shown to be malignant by further follow-up, and 3 were not resected because of refusal or the patient??s age. In 7 patients, mural nodules stayed within 9?mm. The remaining 88 patients lacked mural nodules in their branch duct IPMNs throughout the follow-up. The occurrence of invasive carcinoma around the IPMN was not indicated by imaging examinations in any patient. Univariate analysis showed that the size of the cyst at baseline significantly predicted the development of a mural nodule that reached 10?mm during follow-up (P?=?0.05).

Conclusions

A mural nodule of 10?mm is appropriate as an indicator of surgery in the follow-up of branch duct IPMN.     

Single-institution validation of the international consensus guidelines for treatment of branch duct intraductal papillary mucinous neoplasms of the pancreas

Background

The international consensus guidelines (the guidelines) for management of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas recommend surgical resection of branch duct IPMNs with any of the following features: cyst size >30 mm, mural nodules, main pancreatic duct diameter >6 mm, positive cytology, and symptoms. The aim of this study was to evaluate the usefulness of these guidelines for resection of branch duct IPMNs.

Methods

We reviewed 84 consecutive patients with branch duct IPMNs who underwent surgical resection at our hospital between January 1984 and December 2007.

Results

Sixty-nine patients had indications for resection according to the guidelines. Malignant IPMNs had significantly larger cysts than benign tumors (P = 0.026). Patients with malignant IPMNs had significantly more indications for resection than those with benign IPMNs (2.6 ± 1.0 vs. 1.7 ± 0.9, P < 0.001), and 36 of the 37 patients with malignant IPMNs had indications. The sensitivity of the guidelines for predicting malignancy was 97.3%. One of 15 patients without indications had malignancy, and the specificity was low (29.8%).

Conclusions

The guidelines show a high sensitivity for predicting malignancy of branch duct IPMNs, but the specificity is low. The cyst size and the total number of indications in each patient should be taken into account when predicting the risk of malignancy for branch duct IPMNs.     

Can the location of the mural nodule indicate benign or malignant in branch duct-type intraductal papillary mucinous neoplasm of the pancreas?

Background/ObjectivesIntraductal papillary mucinous neoplasms (IPMNs) are classified into main duct (MD)-type IPMNs, branch duct (BD)-type IPMNs, and mixed type IPMNs. While MD-type IPMN has a high risk of malignancy and should therefore be considered for resection if the patient is fit, BD-type IPMN needs to be carefully judged for surgical indication. The decision to resect BD-type IPMN is often based on international consensus Fukuoka guidelines 2017, but further investigation is required. In this study, we focused on whether the location of the mural nodule (MN) could be an indicator of malignancy.MethodsWe enrolled 17 cases who had been diagnosed BD-type IPMNs which were surgically resected from January 2016 to December 2019. These cases were classified into benign and malignant group. Subsequently, a clinicopathological study was conducted based on the localization of MN (MN-central type or MN-peripheral type).ResultsAlthough MN was found in 57% (4/11) in the benign group, 88% (7/8) was noted in the malignant group, indicating the presence of MN to be more common in the malignant group. Those with MN consisted of 6 cases of MN-central type and 5 cases of MN-peripheral type. All cases of central type were malignant compared to only one case of the peripheral group being confirmed on histology as cancer.ConclusionBD-IPMN with central mural nodule should be considered high risk for malignancy.     

Preoperative evaluation of malignancy in intraductal papillary mucinous neoplasms of the pancreas, especially in relation to dysplastic epithelial changes

BACKGROUND/AIMS: Intraductal papillary mucinous neoplasms have a better prognosis than ductal adenocarcinomas of the pancreas. The aim of this study was to evaluate the malignant potential of IPMNs by their preoperative images. METHODOLOGY: Forty-three intraductal papillary mucinous neoplasms were divided into 3 duct ectatic types using preoperative images (the main duct type, the branch duct type, and the mixed type), and into 2 groups using resected specimens (the malignant group including severe dysplasia based on the WHO classification and the benign group). The diameters of the tumor, main pancreatic duct and mural nodule were measured on the images. RESULTS: Two thirds of main duct type cases were in the malignant group. For the branch duct and mixed types, the diameters of the tumor and detectable mural nodules were larger in the malignant group than in the benign group. A tumor diameter larger than 3.5cm and a mural nodule diameter larger than 6mm were risk factors for malignancy (p < 0.05). CONCLUSIONS: The main duct type, a tumor larger than 3.5cm of the branch duct or mixed type, and a mural nodule larger than 6mm were all indicators of malignancy risk.     

Controversies in the management of pancreatic IPMN

Although considerable progress has been made in our understanding of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, some issues still remain to be resolved. Uncertainty exists regarding the classification of IPMNs. The necessity of the mixed-type category of IPMN and whether such lesions should be defined radiographically or histologically needs to be determined. The preoperative distinction of branch duct IPMNs from nonmucinous cysts should be further investigated so that potentially malignant lesions can be identified and management strategies guided effectively. The role and safety of cystic fluid analysis remains to be clarified in this context. With regard to the diagnosis of malignancy in branch duct IPMNs, criteria for identifying malignancy need to be re-evaluated. The presence of mural nodules is a very reliable predictor; however, controversy exists over the value of size as a reliable indicator. Criteria with increased specificity are needed, perhaps including histological subtype of lesion, to reduce the false-positive rate of the present criteria. Finally, the best modality and interval for surveillance of branch duct IPMNs requires determination because of its significance in terms of malignant transformation, development of distinct ductal adenocarcinoma and disease recurrence after resection.     

Clinicopathological features and medical management of intraductal papillary mucinous neoplasms

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMN) are a clinicopathological entity that is being diagnosed with increasing frequency. However, the best approach to medical management of IPMN needs to be clarified. The aim of the present study was to identify preoperative features that may be predictors of malignant IPMN, and to define the medical management of IPMN of the pancreas. METHODS: A total of 23 patients who underwent surgical resection for IPMN of the pancreas at Kochi Medical School between 1982 and 2004 were examined. Multivariate Cox regression analysis was used to identify factors independently associated with IPM carcinoma. RESULTS: Among the 23 patients, 12 had IPMN adenoma, three had borderline IPMN, four had IPMN with carcinoma in situ, and four had IPMN with invasive carcinoma. In multivariate analysis, elevated serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 levels were found to be preoperative predictors of malignant IPMN. These results suggest that the following IPMN of the pancreas should be resected: (i) IPMN of the pancreas situated in the main duct; (ii) IPMN located in the branch duct if the size of the cystic lesion is >30 mm and the mural nodules are >5 mm in height by endoscopic ultrasound (EUS); and (iii) the diameter of the main pancreatic duct is >10 mm by endoscopic retrograde pancreatography (ERP). Careful observation of patients with branch-type IPMN with small cysts and/or without mural nodules is recommended as a management strategy. CONCLUSION: The present study reinforces the need for immediate surgical resection of malignant IPMN and suggests indicators for IPMN that should assist physicians in making decisions on treatment options.     

Analysis of clinicopathological features and predictors of malignancy in intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND/AIMS: Intraductal papillary mucinous neoplasms (IPMNs) are increasingly recognized, but it is very difficult to evaluate accurately the malignancy of these neoplasms by modern imaging. We reviewed our experience in order to elucidate predictors of tumor malignancy, invasiveness, and outcome. METHODOLOGY: The clinicopathological features and surgical outcomes of 57 patients with IPMNs who underwent surgery in Nagoya University Hospital were analyzed. RESULTS: The histological diagnosis was adenoma in 40, borderline in 1, carcinoma in situ (CIS) in 7, and invasive carcinoma in 9 patients. Patients with invasive carcinomas had significantly shorter survival rates than patients with benign IPMNs or CIS (p < 0.0001). Multivariate analyses revealed that the main duct or the combined type was significantly predictive of malignancy, and both main duct or combined type and diabetes mellitus were associated significantly with invasive carcinoma. CONCLUSIONS: IPMNs generally grow slowly, but have a malignant potential that warrants radical surgical treatment when the tumor component invades the parenchyma. Our results suggest that the above factors should be considered in surgical management. The main duct type of IPMN or IPMN with mural nodules is potentially malignant or invasive. Therefore, radical operative management is indicated in these IPMNs.     

Surgical decompression in the patients of pancreatic intraductal papillary mucinous neoplasm

Intraductal papillary mucinous neoplasm (IPMN) is characterized by cystic dilatation of the main and/or branch pancreatic duct by intraductal growth of mucin-producing columnar epithelia. The malignancy is determined by the degree of epithelial dysplasia. Because most IPMNs are slow growing and the prognosis may be favorable even when the IPMN is malignant, aggressive surgical treatment is suggested after considering operative and postoperative risks. Palliative surgery should be considered in some circumstances, such as other synchronous malignancy or systemic comorbidity. Here, we report two patients with IPMN treated successfully by surgical decompression of pancreatic duct.     

Intraductal papillary mucinous neoplasm and acute pancreatitis

Intraductal papillary mucinous neoplasms (IPMNs) are cystic pancreatic tumors that arise from the pancreatic ducts and are increasingly reported worldwide. Both benign and malignant tumors of the pancreas are thought to contribute to recurrent pancreatitis possibly by pancreatic duct obstruction, and IPMNs contribute to a major share of this burden. The rate of acute pancreatitis (AP) in IPMN patients in the largest published surgical series has varied from 12% to 67%. IPMN may be categorized into 3 forms on the basis of the areas of involvement: main pancreatic duct (MD-IPMN), side branch (SB-IPMN), or combined. Both MD-IPMN and SB-IPMN may be the cause of pancreatitis. The risk of AP seems to be similar with both main duct IPMN and SB-IPMN, although data are controversial. AP in IPMN patients is not severe and often recurs without treatment. The rate of AP does not seem to differ among benign and malignant IPMNs, and the correlation between the malignant potential and the occurrence of AP is ill defined. AP seems to occur more often in patients with IPMN that in those with usual pancreatic adenocarcinoma possibly because of obstruction of the main duct by thick, abundant mucus secretion. Although the Sendai guidelines recommend surgical resection in patients with SB-IPMN with AP, data are controversial. Moreover, in patients with an episode of pancreatitis, the finding of pancreatic cysts is often attributed to pseudocysts or fluid collections that make the diagnosis of IPMN less suspicious. Future longitudinal and prospective studies to understand the natural history of AP in patients with IPMN are required to better manage patients with recurrent AP in the setting of IPMN.     

CLINICAL SIGNIFICANCE OF INTRADUCTAL ULTRASONOGRAPHY FOR DIAGNOSIS OF INTRADUCTAL PAPILLARY MUCINOUS NEOPLASM OF THE PANCREAS

Intraductal ultrasonography (IDUS) is useful for evaluating the horizontal spread along the main pancreatic duct in cases of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, thus providing valuable information for the determination of the resection line at surgery. Differentiation between benign and malignant IPMN is also indispensable for management decisions. Measurement of the height of mural nodules by IDUS is expected to be useful for differential diagnosis of IPMN. Because IDUS cannot always demonstrate whole lesions, especially in branch duct IPMN, endoscopic ultrasonography plays a complementary role in such cases.     

Pancreatic juice cytology in IPMN of the pancreas.

BACKGROUND: Intraductal papillary-mucinous neoplasm (IPMN) of the pancreas is a disease ranging from adenoma to borderline (with moderate dysplasia) and further to carcinoma (noninvasive and invasive) and surgical strategy is different by the grades of dysplasia. METHODS: Preoperative pancreatic juice cytology in IPMN was reviewed in 71 patients with IPMN who underwent surgical resection. RESULTS: The IPMN was adenoma in 48 patients, borderline in 13 and carcinoma (invasive) in 10. The sensitivity of pancreatic juice cytology in malignant IPMN was 40% (4/10). In 4 patients with the 48 IPM adenomas, diagnosis of pancreatic juice cytology was class IV or V. One of the 4 cases was considered to be an overdiagnosis of cytology, but the other 3 cases were considered to be a consequence of accompanying carcinoma in situ (or PanIN-3) (2 patients) or invasive ductal adenocarcinoma (1 patient) apart from IPMN. Sensitivity of pancreatic juice cytology was higher in IPMN of the main duct type with mucin hypersecretion and with mural nodules. CONCLUSIONS: These findings suggest that pancreatic juice cytology in IPMN is useful especially in the main duct type with mucin hypersecretion and mural nodules. When the diagnosis of pancreatic juice cytology is malignant in otherwise benign-looking IPMNs, coexistence of pancreatic carcinoma should be suspected.     

Resektion zystischer Pankreastumoren

Cystic tumors of the pancreas are diagnosed increasingly more due to increasing life expectancy and the moderate use of modern radiological diagnostics. Intraductal papillary mucinous neoplasms of the pancreas (IPMN), mucinous cystic neoplasms (MCN), solid pseudopapillary neoplasms (SPN) and serous cystic neoplasms (SCN) represent over 90?% of all cystic neoplasms of the pancreas. Although serous cystic lesions have a low or even no potential for malignant transformation, they are mostly resected when symptomatic. In contrast, mucinous lesions have an increased malignant potential and should therefore be resected in almost all cases. While this is true for all cases of MCNs and SPNs this is controversial for all IPMNs as they show a wide spectrum of morphological variants. The IPMNs may arise in the main pancreatic duct, major side branches or in both (mixed type). Although all IPMNs are considered to be precursor lesions to pancreatic adenocarcinomas it is not clear what the time course of such potential neoplastic transformation might be and whether all lesions progress to malignant tumors. As no currently used diagnostic test can reliably differentiate between benign and malignant tumors, the majority of newly diagnosed IPMNs should undergo surgical resection. According to current treatment guidelines (Sendai criteria), asymptomatic side branch IPMNs of less than 3 cm in diameter without suspicious radiological features, such as nodules, thickness of the cystic wall or size progression can be treated conservatively without the need for surgical resection. Recently, this approach has become controversial due to a relevant number of IPMNs reported as Sendai negative that showed malignant transformation on final histological examination.     

Imaging features of intraductal papillary mucinous neoplasms of the pancreas in multi-detector row computed tomography

AIM： To retrospectively evaluate the imaging features of pancreatic intraductal papillary mucinous neoplasms （IPMNs） in multi-detector row computed tomography （MDCT）.
METHODS： A total of 20 patients with pathologicallyconfirmed intraductal papillary mucinous neoplasms （IPMNs） were included in this study. Axial MDCT images combined with CT angiography （CTA） and multiplanar volume reformations （MPVR） or curved reformations （CR） were preoperatively acquired. Two radiologists （Tan L and Wang DB） reviewed all the images in consensus using an interactive picture archiving and communication system. The disputes in readings were resolved through consultation with a third experienced radiologist （Chen KM）. Finally, the findings and diagnoses were compared with the pathologic results.
RESULTS： The pathological study revealed 12 malignant IPMNs and eight benign IPMNs. The diameters of the cystic lesions and main pancreatic ducts （MPDs） were significantly larger in malignant IPMNs compared with those of the benign IPMNs （P 〈 0.05）. The combinedtype IPMNs had a higher rate of malignancy than the other two types of IPMNs （P 〈 0.05）. Tumors with mural nodules and thick septa had a significantly higher incidence of malignancy than tumors without these features （P 〈 0.05）. Communication of side-branch IPMNs with the MPD was present in nine cases at pathologic examination. Seven of them were identified from CTA and MPVR or CR images. From comparison with the pathological diagnosis, the sensitivity, specificity, and accuracy of MDCT in characterizing the malignancy of IPMN of the pancreas were determined to be 100%, 87.5% and 95%, respectively.
CONCLUSION： MDCT with CTA and MPVR or CR techniques can elucidate the imaging features of IPMNs and help predict the malignancy of these tumors.     

Intraductal papillary-mucinous tumors of the pancreas: differential diagnosis between benign and malignant tumors by endoscopic ultrasonography

OBJECTIVES: Recently, intraductal papillary-mucinous tumor (IPMT) of the pancreas has increasingly been recognized. However, differential diagnosis between benign and malignant IPMT is often difficult using conventional imaging modalities. The purpose of this study was to retrospectively investigate the value of endoscopic ultrasonography (EUS) for differentiating malignant from benign IPMT. METHODS: A total of 51 patients with IPMT were preoperatively examined by EUS. The endosonograhic findings were compared with histopathological findings of the resected specimens. RESULTS: In main duct type IPMT, the diameter of the main pancreatic duct (MPD) was > or =10 mm in seven of the eight malignant tumors, compared with two of the seven benign tumors (p < 0.05). In branch duct type IPMT, three of the four large tumors (>40 mm) with irregular thick septa were malignant lesions. In both main duct type IPMT and branch duct IPMT, eight patients had large mural nodules (>10 mm); seven of the eight tumors were malignant and one of the eight tumors was benign. When the tumor was diagnosed as malignant according to above three findings, EUS was able to differentiate between malignant and benign IPMT with an accuracy of 86%. CONCLUSIONS: Main duct type tumors with > or =10 mm dilated MPD, branch duct type tumors (>40 mm) with irregular septa, and large mural nodules (>10 mm) strongly suggest malignancy on EUS. EUS would be a useful modality for differentiating between benign and malignant IPMT.     

MANAGEMENT OF INTRADUCTAL PAPILLARY MUCINOUS NEOPLASM OF THE PANCREAS

Intraductal papillary mucinous neoplasms of the pancreas (IPMNs) consist of main duct (MD) type and branch duct (BD) type. The authors describe their way of thinking regarding diagnostic modalities and management for BD type IPMNs. Endoscopic ultrasonography (EUS) and intraductal ultrasonography (IDUS) provide high resolution images of main and branch pancreatic ducts. The cases with nodules demonstrated by EUS and/or IDUS regardless of the size are the indication of operation. There were 235 cases with BD type IPMN who underwent EUS and IDUS between April 1991 and June 2005. A total of 94 patients underwent surgical resection and were histopathologically diagnosed (carcinoma, 10 cases; adenoma, 64 cases; hyperplasia, 20 cases). Diagnoses of 79 cases with nodules detected by EUS or IDUS preoperatively were 10 carcinomas, 61 adenomas and eight hyperplasias. Diagnoses of 15 cases without nodules but with symptoms were three adenomas, 12 hyperplasias and no carcinoma. The authors think that the combination of EUS and IDUS is the best way for diagnosing BD type IPMNs in the present state.