Differential diagnosis of intraductal papillary‐mucinous tumor of the pancreas by endoscopic ultrasonography and intraductal ultrasonography

Background: Intraductal papillary‐mucinous tumor (IPMT) of the pancreas has a broad spectrum of histology ranging from hyperplasia to adenocarcinoma. Therefore, it is important to differentiate between the malignant and benign lesions to determine the therapeutic strategy for IPMT. Patients and Methods: Thirty‐nine patients with IPMT (27 men and 12 women, mean age: 63.3 years) underwent surgery between January 1985 and March 2002. The size of the cystic lesion, the maximum diameter of the main pancreatic duct (MPD), and the height of the papillary tumor inside the cyst were investigated by endoscopic ultrasonography (EUS) and/or intraductal ultrasonography (IDUS) before operation. These preoperative clinical findings were compared with the pathological findings of the resected specimen. Results: The size of the cystic lesion, the diameter of MPD, and the height of the papillary tumor in cases with malignant IPMT (invasive and non‐invasive carcinoma) were larger than those in cases with benign IPMT (adenoma and hyperplasia). Analysis of the images of the lesions revealed that the following three factors are important for diagnosing IPMT: (i) the size of the cystic lesion is ≥ 30 mm; (ii) the diameter of MPD is ≥ 8 mm; (iii) the height of the papillary tumor inside the cyst is ≥ 3 mm. It was not significant to differentiate between benign and malignant IPMT based on factor (i), but statistically significant (P < 0.001) based on factors (ii) and (iii). Conclusions: EUS and IDUS are useful in the differential diagnosis of IPMT, especially in the differentiation between malignant and benign IPMT.     

PERORAL PANCREATOSCOPY AND INTRADUCTAL ULTRASONOGRAPHY IN DETERMINING THE RESECTION LINES OF INTRADUCTAL PAPILLARY MUCINOUS TUMORS OF THE PANCREAS

In patients with malignant intraductal papillary–mucinous tumors (IPMT), the tumor spread along the main pancreatic duct is generally inspected as mural nodules within the ducts by peroral pancreatoscopy (POPS). Even the lower mural nodules including fish‐eggs‐like lesions and granular mucosa continued to the main taller mural nodules should be resected. Mural nodules along the main duct and cystic dilation of the branch ducts observed by intraductal ultrasonography (IDUS) are regarded as the tumor spread. Although POPS is superior to IDUS in identifying mural nodules along the main duct, POPS has limitations to detect mural nodules within the branch ducts. Therefore, the accuracy of the diagnosis by POPS is higher in main duct IPMT, whereas that by IDUS is higher in branch duct IPMT. These modalities should be performed as complementary tests in determining the resection lines preoperatively.     

LATERAL SPREAD ALONG THE MAIN PANCREATIC DUCT IN BRANCH‐DUCT INTRADUCTAL PAPILLARY‐MUCINOUS NEOPLASMS OF THE PANCREAS: USEFULNESS OF INTRADUCTAL ULTRASONOGRAPHY FOR ITS EVALUATION

Background: Intraductal papillary mucinous neoplasms (IPMN) of the pancreas tend to spread intraepithelially along the pancreatic duct wall. We evaluated histopathological intraductal lateral spread (LS) along the main pancreatic duct (MPD) from branch‐duct IPMN and investigated the usefulness of intraductal ultrasonography (IDUS) for its preoperative diagnosis. Patients and Methods: Twenty‐four patients with branch‐duct IPMN who had undergone preoperative IDUS and surgery were reviewed clinicopathologically. The prevalence and histological length of LS along the MPD from branch‐duct IPMN, characteristics of the patients with LS, and efficacy of LS assessment by IDUS were examined. Results: LS along the MPD was observed in 54% of the subjects. In the group of patients with LS, its mean length was 25.2 ± 16.8 mm (5–50 mm) and the diameter of the MPD was 6 mm or greater. Of the patients with LS, those in whom the length of LS along the MPD was longer than the diameter of the cystically dilated branch accounted for 30%. The diameter of the MPD in the group with LS was significantly greater than that in the group without LS (P = 0.03). The sensitivity, specificity, and overall accuracy of IDUS in the detection of LS were 92%, 91%, and 92%, respectively. Conclusion: LS along the MPD was detected in about half of the resected cases of branch‐duct IPMN. Preoperative transpapillary IDUS may be beneficial for the determination of the resection line, especially in those branch‐duct IPMN patients in whom the MPD is 6 mm or greater in diameter.     

Endosonographic diagnosis of intraductal papillary‐mucinous pancreatic tumors by intraductal ultrasonography

Background: Intraductal papillary‐mucinous pancreatic tumors (IPMT) are intraductal lesions formed by mucin‐producing epithelium, which proliferates in a papillary pattern, and presents a spectrum from hyperplasia to adenocarcinoma. The value of intraductal ultrasonography (IDUS) for excluding malignancy has not been assessed in a case series previously. Methods: Intraductal ultrasonography was performed in 17 patients with IPMT (12 with adenocarcinoma and five with adenoma) between November 1993 and June 2002. Intraductal ultrasonography was used to determine the maximum height and maximum cross‐sectional area of protruding lesions. Results were compared after dividing the tumors into three groups: a benign lesion group, a non‐invasive cancer group, and an invasive cancer group. The resection line was located over 10 mm from the edge of the protruding lesion visualized by intraductal ultrasonography. Results: All adenocarcinomas had a height ≥ 5 mm and all benign lesions had a height ≤ 3 mm, with this difference being significant (P = 0.0034). The height of non‐invasive and invasive cancer was similar. The maximum cross‐sectional area of the protrusion was smaller for benign lesions (≤ 15 mm²) than for non‐invasive cancer (≥ 34 mm², P = 0.0034). The cross‐sectional area of the protrusion was greater in patients with invasive cancer than in those with non‐invasive cancer (P = 0.0367). All surgical margins have remained clear and no patient has suffered from a recurrence during 1 to 8 years of follow‐up computed tomography and ultrasonography. Conclusions: Intraductal ultrasonography can distinguish benign from malignant IPMT based on the height and maximum cross‐sectional area of the protruding tumor.     

Diagnosis and patient management of intraductal papillary-mucinous tumor of the pancreas by using peroral pancreatoscopy and intraductal ultrasonography.

BACKGROUND & AIMS: Intraductal papillary-mucinous tumor (IPMT) of the pancreas has attracted increasing interest because of its unique presentation. The differential diagnosis between malignant and benign tumors is extremely important in the determination of the therapy for IPMT. The aims of this study are to determine the usefulness of peroral pancreatoscopy (POPS) and intraductal ultrasonography (IDUS) in IPMT for the differentiation of malignant from benign disease, and to evaluate the significance of these techniques as new preoperative examinations. METHODS: Sixty histopathologically confirmed patients with IPMT underwent POPS and/or IDUS preoperatively. POPS was perfomed in all patients, and IDUS in 40. Findings of POPS and IDUS were compared with histopathology of resected specimens. The postoperative follow-up data were analyzed. RESULTS: Protruding lesions were detected by POPS in 40 patients. They were classified into 5 groups. Fish-egg-like type with vascular images, villous type, and vegetative type were considered to be malignant. By IDUS, lesions protruding 1 mm or more were observed in 36 patients. Of the lesions protruding 4 mm or more, 88% were malignant. Combination of POPS and IDUS improved the differential diagnosis between benign and malignant IPMT. The 3-year cumulative survival rate and disease-free survival rate were extremely high at 95% and 93%, respectively. CONCLUSIONS: The combination of POPS and IDUS results in a considerably improved differential diagnosis between malignant and benign IPMT and is useful for determining an effective therapeutic approach. These new techniques can contribute to improvements in postoperative results.     

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.     

WHAT KIND OF BENEFIT DO WE EXPECT FOR PERORAL PANCREATOSCOPY IN THE DIAGNOSIS OF INTRADUCTAL PAPILLARY MUCINOUS TUMOR OF THE PANCREAS?

Intraductal papillary mucinous tumor (IPMT) of the pancreas is characterized by slow growth and a relatively favorable prognosis, however, invasive cancer originating in an IPMT is associated with a poor prognosis. Although various parameters in imaging modalities have been advocated to differentiate between benign IPMN and malignant ones, it is not easy to obtain definite diagnosis based on these parameters. Peroral pancreatoscopy (POPS) allows a clear and direct visualization of the pancreatic duct, providing useful information regarding tumor nature in IPMT. The authors have studied the usefulness of POPS in the diagnosis of IPMT. Nevertheless, its usefulness is not necessarily widely accepted and the significance of POPS is still controversial. In this review, the authors intended to address the diagnostic value of POPS and to clarify its role in the diagnosis of IPMT. The authors think treatment of IPMT can be improved by introducing POPS because the determination of surgical procedure as well as the area of resection based on the preoperative diagnosis of the involvement of the main pancreatic duct and branch duct is inevitable.     

Prospective evaluation of indeterminate ERCP findings by intraductal ultrasound

BACKGROUND AND AIM: Although the role of intraductal ultrasound (IDUS) in the evaluation of specific disease entities is well known, its utility in evaluating indeterminate findings in a heterogeneous group of patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) is unknown. This study evaluates the diagnostic accuracy of IDUS in patients with indeterminate findings at ERCP. METHODS: This was a prospective study of all patients who underwent IDUS for evaluation of an indeterminate biliary stricture or main pancreatic duct (MPD) dilation noted at ERCP over an 8-month period. The accuracy of IDUS was established based on long-term follow-up, surgery, or further investigations. RESULTS: Twenty-nine (5%) of 600 patients who underwent ERCP had an indeterminate finding that warranted further evaluation by IDUS: this was biliary stricture in 19 patients and MPD dilation in 10. Technical success was 100%. Mean duration of follow-up was 435 days (range 192-614 days). In patients with biliary stricture, IDUS diagnosed 11 as benign and eight as malignant. In patients with MPD dilation, IDUS diagnosed intraductal papillary mucinous tumor in six patients and chronic pancreatitis in four. Findings on IDUS supported the correct diagnosis in 27 of 29 patients (93%). In two patients with dominant hilar stricture in the setting of primary sclerosing cholangitis, IDUS was false positive in one and false negative in the other. One patient died of multiorgan failure due to post-ERCP pancreatitis. CONCLUSIONS: A technically easy procedure, IDUS offers unique advantages in the evaluation of patients with indeterminate findings at ERCP.     

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.     

INTRADUCTAL ULTRASONOGRAPHY BEFORE BILIARY DRAINAGE AND TRANSPAPILLARY BIOPSY IN ASSESSMENT OF THE LONGITUDINAL EXTENT OF BILE DUCT CANCER

Aim: We evaluated the diagnostic efficacy of transpapillary intraductal ultrasonography before biliary drainage (IDUS‐BD) and transpapillary biopsy (TPB) for the assessment of the longitudinal extent of bile duct cancer. Methods: Between November 1999 and January 2005, we performed IDUS‐BD and TPB preoperatively in 27 patients with carcinoma of the extrahepatic bile duct. Following IDUS‐BD, TPB was performed under fluoroscopic guidance immediately after endoscopic sphincterotomy. The diagnostic efficacy of IDUS‐BD and TPB for the longitudinal extent of the cancer and the complications which accompanied the procedure were evaluated. Results: The overall success rate of sampling and the diagnostic accuracy of bile duct cancer by TPB were 85.3% (192/225) and 85% (23/27), respectively. The sensitivity, specificity and accuracy of the assessment of the longitudinal extent of cancer on the hepatic and duodenal sides by IDUS‐BD were 82%, 70%, 78% and 85%, 43%, 70%, respectively. Those by a combination of IDUS‐BD and TPB were 88%, 80%, 85% and 77%, 86%, 80%, respectively. Overestimation of the longitudinal extent of BD cancer by IDUS‐BD was mainly due to inflammation and obscure images, especially resulting from collapse of the bile duct on the duodenal side of the tumor, and was corrected by TPB in four of five patients. No serious complications occurred following the combination of IDUS‐BD and TPB. Conclusions: TPB is useful for preoperative histological diagnosis of bile duct cancer. The combination of IDUS‐BD and TPB is practical for evaluation of its longitudinal extent; basically, IDUS‐BD is sufficient on the hepatic side of the tumor, but concomitant TPB is recommended on the duodenal side.     

管腔内超声对胰胆疾病诊断价值的初探

目的 评价管腔内超声(IDUS)检查在胰胆疾病中的诊断价值.方法 回顾性分析北京协和医院2006年7月至2007年8月期间,对19例胰胆疾病患者的ERCP与IDUS检查结果及其相关临床资料.结果 (1)19例患者中梗阻性黄疸17例,胰腺导管内乳头状黏液瘤(IPMT)2例.17例梗阻性黄疸中胆管癌6例,胰腺癌2例,胆囊癌2例,胆管结石合并胆管狭窄2例,自身免疫性胰腺炎2例,十二指肠乳头腺癌1例,十二指肠乳头腺瘤1例,硬化性胆管炎1例.19例诊断中11例经手术或组织病理学证实.(2)ERCP对胰胆疾病诊断的正确率为73.7%(14/19),IDUS对胰胆疾病诊断的正确率为84.2%(16/19),ERCP联合IDUS对胰胆疾病诊断的正确率89.5%(17/19).(3)ERCP对胆管良恶性狭窄鉴别诊断的敏感性和特异性分别为100.0%(11/11)和83.3%(5/6),IDUS对胆管良恶性狭窄鉴别诊断的敏感性和特异性分别为100.0%(11/11)和100.O%(6/6).(4)ERCP对胆管癌诊断的敏感性和特异性分别为83.3%(5/6)和60.0%(3/5),IDUS对胆管癌诊断的敏感性和特异性分别为100.0%(6/6)和40.0%(2/5).结论 ERCP检查同时进行IDUS检查能提高胰胆疾病的诊断率.IDUS对胆管良恶性狭窄的鉴别诊断具有较高的敏感性和特异性,但在具体区分恶性狭窄的病因上尚存在一定的困难.     

Transpapillary intraductal ultrasound in the evaluation of dominant bile duct stenoses in patients with primary sclerosing cholangitis

Objective. Primary sclerosing cholangitis (PSC) is associated with the development of cholangiocarcinoma (CC) in approximately 9% of patients. Neither cholangiography nor endoscopic tissue sampling can reliably distinguish between CC and benign dominant bile duct stenosis. The aim of the present study was to assess the value of intraductal ultrasonography (IDUS) in distinguishing between benign and malignant dominant stenoses in PSC patients. Material and methods. Forty PSC patients with dominant bile duct stenoses were studied prospectively. Transpapillary IDUS and endoscopic tissue sampling were performed in addition to endoscopic retrograde cholangiography (ERC). Cholangiography and IDUS findings were classified as malignant or benign by the investigators. Final diagnosis of malignant stenosis was based on positive histology and/or cytology, whereas a benign character was assumed in cases of negative tissue sampling and uneventful extended clinical follow-up. Results. Eight PSC patients (20%) had dominant bile duct stenoses caused by CC, whereas 32 out of 40 patients (80%) had benign dominant bile duct stenoses. IDUS was significantly superior to ERC for detection of malignancy in terms of sensitivity (87.5% versus 62.5%, p=0.05), specificity (90.6% versus 53.1%, p<0.001), accuracy (90% versus 55%, p<0.001), positive predictive value (70% versus 25%, p<0.001), and negative predictive value (96.7% versus 85%, p=0.049). Conclusions. Transpapillary IDUS significantly increases the ability to distinguish malignant from benign dominant bile duct stenoses in patients with PSC.     

DIAGNOSIS AND MANAGEMENT OF INTRADUCTAL PAPILLARY MUCINOUS TUMORS OF THE PANCREAS

Intraductal papillary mucinous tumors (IPMT) of the pancreas are histopathologically adenocarcinoma, adenoma, or even hyperplasia, and, therefore, selection of the treatment strategy is very important. While the International Consensus Guidelines for Management of Intraductal Papillary Mucinous Neoplasms and Mucinous Cystic Neoplasms of the Pancreas have been published, the authors discussed the diagnosis and management of IPMT in the session of Endoscopy Forum Japan 2005. All the discussants agreed to the guideline’s recommendation to resect all main duct IPMT. However, they reserved their consensus on the recommendation of resection for branch duct IPMT which are 5 mm or higher in the mural nodule height. General opinion is that treatment should be considered for lesion where the main duct diameter is over 7 mm, and that dilated branch duct diameter is not an important factor, while it is defined as an important factor in the guidelines.     

A Case of Non-Alcoholic Pancreatitis Treated with Steroid Followed-up Using Intraductal Ultrasonography and Endoscopic Retrograde Pancreatography

A 42-year-old man with jaundice was found to have a pancreatic mass in the head by ultrasonography. Endoscopic retrograde cholangiopancreatography (ERCP) showed a segmental narrowing of the main pancreatic duct (MPD) with a mild upstream dilatation and an extrinsic stenosis of the inferior common bile duct (CBD). lntraductal ultrasonography (IDUS) showed a diffuse hypoechoic area with echogenic spots surrounding the narrowed MPD and the stenotic CBD. He was suspected of having autoimmune pancreatitis because of a characteristic pancreatogram, and 30 mg/day predniso-lone was started. Two weeks later, the narrowing of the MPD and the stenosis of the CBD improved dramatically. But the hypoechoic area remained separate from the MPD with a fine reticular pattern on the inside. It completely disappeared in the eighth week. The diachronic changes in the IDUS were characteristic in that the hypoechoic area, which initially surrounded the MPD, disappeared near the MPD, followed by a distant area. This might explain the discrepancy between the images of ERCP and IDUS in the second week of steroid therapy.     

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.     

Three-dimensional Ultrasonography Using Ultrasonic Probes by the Transpapillary Approach for Diagnosis of Pancreatobiliary Diseases

Abstract: Three-dimensional (3D) intraductal ultrasonography (IDUS) is more useful than two-dimensional IDUS for the diagnosis of pancreatobiliary disease. We investigated the advantages and disadvantages of the transpapillary approach for 3D-IDUS using a newly developed system for pancreatobiliary application. In total 12 patients with a sufficiently wide orifice were examined, bile duct (BD) scanning being successful in 100% of attempted cases and main pancreatic duct (MPD) scanning in 85.7%. In all cases, acceptable radial and linear images were obtained and 3D diagnosis was accomplished. However, several primary problems were experienced; 1) The 3D probe is relatively inflexible, having a thick shaft and a long tip, such that insertion into the BD or MPD can be somewhat difficult; 2) Clear images of the BD or MPD wall were not always obtained because of artifacts produced by the 3D probe itself; 3) In some cases, linear images could not be reconstructed with BD or MPD scanning despite sufficiently clear radial scan images. In the future, development of new 3D probes with more flexible and thinner shafts, and shorter tips, should considerably enhance the diagnostic capacity of IDUS for the pancreatobiliary system.     

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.     

Newly Developed Ultrasonic Probe With Ropeway System for Transpapillary Intraductal Ultrasonography of the Bilio–Pancreatic Ductal System

Background: Intraductal ultrasonography of the bile/pancreatic duct using a thin‐caliber ultrasonic probe (IDUS) provides excellent images of these ducts and the surrounding structures. Insertion of the device through the papilla of Vater is essential to carry out this examination. We developed a new probe with a ropeway system (XUM5RG‐29R; Olympus, Tokyo) for transpapillary IDUS. Its usefulness such as ease of application and safety were prospectively evaluated. Patients and methods: During the period of October 1997 to April 1998, transpapillary IDUS using the probe was performed in 194 patients at seven medical institutions. The success rates of insertion of the probe into the bile/pancreatic duct, observation of the area of interest, and the incidence of complications were evaluated. Results: Passage of the probe through the papilla was successful without difficulty in all the patients. Successful introduction of the probe into the pancreatic duct, bile duct and both of the ducts was achieved in 98.4, 100 and 85% of the patients, respectively. Once the probe was introduced into the aimed duct, it was possible to obtain IDUS images of the area of interest in all but five patients. Mild acute pancreatitis developed in eight patients (4.1%), all of whom recovered with conservative therapy only. Conclusions: It is possible to introduce the new ultrasonic probe into the desired duct once a guide wire has been inserted. This type of ultrasonic probe is quite useful when performing transpapillary IDUS of the bile and/or pancreatic duct.     

Surgical treatment of intraductal papillary-mucinous tumor (IPMT) of the pancreas: operative indications based on surgico-pathologic study focusing on invasive carcinoma derived from IPMT

Background/Purpose. Between 1979 and 2000, 51 patients with intraductal papillary-mucinous tumor (IPMT) of the pancreas underwent surgical resection. Methods. The patients were reviewed to disclose the surgical pathology of invasive carcinoma derived from IPMT and to determine the surgical indications for IPMT on the basis of the pathologic findings. Results. The incidence of invasive carcinoma derived from IPMT according to the localization of the tumor was as follows: 4/9 (44%) in the main pancreatic duct (MPD type), 4/9 (44%) showing ductal spread from the MPD to branch ducts (mixed type), and 2/33 (6%) in the 2 branch duct (branch type). The maximal size of the intraductal spread of invasive carcinomas (8 of 18 cases in the MPD and mixed type together and 2 of 33 cases in the branch type) was as follows: 6/8 (75%) in the MPD and mixed type were over 6?cm in size, and the 2-branch-type invasive carcinomas were within the 3-cm size range. Conclusions. We concluded that for both invasive and noninvasive IPMTs, surgical resection was necessary for any MPD or mixed-type IPMTs, and that surgical resection was appropriate for branch-type lesions larger than or equal to 3?cm in diameter, or for lesions smaller than 3?cm showing rapid growth on clinical images.     

Intraductal papillary-mucinous tumors of the pancreas: Clinicopathologic features, outcome, and nomenclature. Members of the Pancreas Clinic, and Pancreatic Surgeons of Mayo Clinic

BACKGROUND & AIMS: Intraductal papillary-mucinous tumor (IPMT) of the pancreatic ducts is increasingly recognized. This study investigated if clinical, imaging, or, histological features predicated outcome, formulated a treatment algorithm, and clarified relationships among IPMT, mucinous cystic neoplasms of the pancreas (MCN), and chronic pancreatitis. METHODS: The medical records, radiographs, and pathological specimens of 15 patients with IPMT (dilated main pancreatic duct or branch ducts with mucin overproduction) who were evaluated between October 1983 and January 1994 were reviewed. RESULTS: One patient had hepatic metastases. Fourteen underwent an operation (6 distal pancreatectomy, 4 total pancreatectomy, and 4 pancreaticoduodenectomy); all had dysplastic intraductal epithelium and chronic pancreatitis, whereas 3 had invasive adenocarcinoma. After a median of 25 months, 10 patients were alive; 3 of 4 with malignant and 2 of 11 with benign IPMT died (P < 0.05). Patients with or without carcinoma had similar clinical and radiographic features. A clinical diagnosis of chronic pancreatitis had been made in 9 patients with benign IMPT and in none with malignant IPMT (P < 0.05). CONCLUSIONS: IPMT is a dysplastic and likely precancerous lesion that is frequently diagnosed as chronic pancreatitis and is separate from MCN. Because it is not possible to distinguish noninvasive from invasive IPMT preoperatively, complete surgical excision of the dysplastic process is our treatment of choice whenever appropriate. (Gastroenterology 1996 Jun;110(6):1909-18)