Intraductal papillary tumors of the pancreas: evaluation with endoscopic ultrasonography

Endoscopic Imaging of Pancreatic Cysts

Pancreatic cystic lesions (PCLs) have been diagnosed with increasing frequency likely due to the widespread use of cross-sectional imaging. A precise diagnosis of the PCL is important because it helps identify patients in need of surgical resection and those who can undergo surveillance imaging. A combination of clinical and imaging findings as well as cyst fluid markers can help classify PCLs and guide management. This review focuses on endoscopic imaging of PCLs including endoscopic and endosonographic features and fine needle aspiration. We then review the role of adjunct techniques, such as microforceps, contrast-enhanced endoscopic ultrasound, pancreatoscopy, and confocal laser endomicroscopy.

Peroral Pancreatoscopy with Videoscopy and Narrow-Band Imaging in Intraductal Papillary Mucinous Neoplasms with Dilatation of the Main Pancreatic Duct

Background/Aims

Endoscopic evaluation of intraductal papillary mucinous neoplasms (IPMNs) is useful in determining whether the lesions are benign or malignant. This study aimed to examine the usefulness of peroral pancreatoscopy (POPS) in determining the prognosis of IPMNs.

Methods

POPS with videoscopy was performed using the mother–baby scope technique. After surgery, computed tomography/magnetic resonance cholangiopancreatography or ultrasonography and blood tests were performed every 6 months during the follow-up.

Results

A total of 39 patients with main pancreatic duct (MPD)–type IPMNs underwent POPS using a videoscope, and the protrusions in the MPD were observed in 36 patients. The sensitivity and specificity of cytology/biopsy performed at the time of POPS were 85% and 87.5%, respectively. Of 19 patients who underwent surgery, 18 (95%) patients had negative surgical margins and 1 (5%) patient had a positive margin.

Conclusions

In IPMNs with dilatation of the MPD, POPS is considered effective if the lesions can be directly observed. The diagnosis of benign and malignant lesions is possible depending on the degree of lesion elevation. However, in some cases, slightly elevated lesions may increase in size during the follow-up or multiple lesions may be simultaneously present; therefore, careful follow-up is necessary.

ACG Clinical Guideline: Diagnosis and Management of Pancreatic Cysts

Pancreatic cysts are very common with the majority incidentally identified. There are several types of pancreatic cysts; some types can contain cancer or have malignant potential, whereas others are benign. However, even the types of cysts with malignant potential rarely progress to cancer. At the present time, the only viable treatment for pancreatic cysts is surgical excision, which is associated with a high morbidity and occasional mortality. The small risk of malignant transformation, the high risks of surgical treatment, and the lack of high-quality prospective studies have led to contradictory recommendations for their immediate management and for their surveillance. This guideline will provide a practical approach to pancreatic cyst management and recommendations for cyst surveillance for the general gastroenterologist.

Applications of Endoscopic Ultrasonography in Pancreatic Cancer

Background

Accurate staging of pancreatic cancer is essential for surgical planning and for identification of locally advanced and metastatic disease that is incurable by surgery. Advances in endoscopic sonography (EUS), computed tomography (CT), and positron emission tomography have improved the accuracy of staging and reduced the number of incomplete surgical resections. Tissue acquisition is necessary in nonsurgical cases when chemoradiotherapy is considered. The complex regional anatomy of the pancreas makes cytologic diagnosis of malignancy at this region difficult without exploratory surgery. Although CT-guided fine-needle aspiration (FNA) is used for this purpose, reports of an increased risk of peritoneal dissemination of cancer cells and a false-negative rate of nearly 20% make this a poor choice. The ability to position the EUS-transducer in direct proximity to the pancreas by means of the stomach and duodenum, combined with the use of FNA, increases the specificity of EUS in detecting pancreatic malignancies.

Methods

The current literature regarding the accuracy of EUS with FNA in the evaluation of pancreatic cancer is reviewed.

Results

EUS accuracy ranges from 78% to 94% for tumor staging and from 64% to 82% for nodal staging. EUS also enables FNA of lesions that are too small to be identified by CT or MRI or too well encased by surrounding vascular structures to safely allow percutaneous biopsy. The accuracy for detecting invasion into the superior mesenteric artery and vein is lower than that for detecting portal or splenic vein invasion, especially for large tumors. EUS permits delivery of localized therapy such as celiac plexus neurolysis for pain control and direct intra-lesional injection of antitumor therapy.

Conclusions

EUS in combination with FNA is a highly accurate method of preoperative staging of pancreatic cancer, especially those too small to be characterized by CT or MRI, and it has the ability to obtain cytological confirmation of pancreatic cancer.

Differential diagnosis of benign and malignant branch duct intraductal papillary mucinous neoplasm using contrast-enhanced endoscopic ultrasonography

AIM: To elucidate the role of contrast-enhanced endoscopic ultrasonography (CE-EUS) in the diagnosis of branch duct intraductal papillary mucinous neoplasm (BD-IPMN).

METHODS: A total of 50 patients diagnosed with BD-IPMN by computed tomography (CT) and endoscopic ultrasonography (EUS) at our institute were included in this study. CE-EUS was performed when mural lesions were detected by EUS. The diagnostic accuracy for identifying mural nodules (MNs) was evaluated by CT, EUS, and EUS combined with CE-EUS. In the patients who underwent resection, the accuracy of measuring MN height with each imaging modality was compared. The cut-off values to diagnose malignant BD-IPMNs based on MN height for each imaging modality were determined using receiver operating characteristic curve analysis.

RESULTS: Fifteen patients were diagnosed with BD-IPMN with MNs and underwent resection. The remaining 35 patients were diagnosed with BD-IPMN without MNs and underwent follow-up monitoring. The pathological findings revealed 14 cases with MNs and one case without. The accuracy for diagnosing MNs was 92% using CT and 72% using EUS; the diagnostic accuracy increased to 98% when EUS and CE-EUS were combined. The accuracy for measuring MN height significantly improved when using CE-EUS compared with using CT or EUS (median measurement error value, CT: 3.3 mm vs CE-EUS: 0.6 mm, P < 0.05; EUS: 2.1 mm vs CE-EUS: 0.6 mm, P < 0.01). A cut-off value of 8.8 mm for MN height as measured by CE-EUS improved the accuracy of diagnosing malignant BD-IPMN to 93%.

CONCLUSION: Using CE-EUS to measure MN height provides a highly accurate method for differentiating benign from malignant BD-IPMN.

Invasive carcinoma derived from "flat type" branch duct intraductal papillary mucinous neoplasms of the pancreas: impact of classification according to the height of mural nodule on endoscopic ultrasonography

BACKGROUND

It has been reported that many branch duct intraductal papillary mucinous neoplasms (BD-IPMN) with a mural nodule (MN) reveal adenocarcinomas. On the other hand, invasive cancer derived from BD-IPMN without MN on endoscopic ultrasound (EUS) also exists. The aim of this study was to elucidate the clinicopathological features of invasive cancer derived from BD-IPMN without MN on EUS.

METHODS

Twenty-one patients pathologically diagnosed with invasive cancer derived from BD-IPMN were included in this study.

RESULTS

Based on the height of MNs on EUS, the subjects could be clearly classified as 12 patients whose background BD-IPMNs had high MNs (nodule-forming type IPMN) and nine whose background BD-IPMNs showed no MNs (flat type IPMN). The background BD-IPMN of the 12 patients with nodule-forming type IPMN were non-gastric type. On the other hand, the background BD-IPMN of the nine patients with flat type IPMN was gastric type. The recurrence rate was higher (33% vs. 67%) and the 5-year survival was worse (76% vs. 33%) in flat type IPMN.

CONCLUSIONS

There may be a pathway for the development of invasive cancer without the formation of an MN in BD-IPMN, and attention should be paid even to the patients with BD-IPMN which does not present an MN.

Comparison of ERCP, EUS, and ERCP combined with EUS in diagnosing pancreatic neoplasms: a systematic review and meta-analysis

In the current study, we performed a systematic review of literature pertaining to the diagnostic value of endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasonography (EUS), and combined ERCP plus EUS to pancreatic cancer. We searched MEDLINE, OVID, and the Cochrane Library for studies evaluating diagnostic validity of ERCP, EUS, and ERCP plus EUS between January 1989 and May 2014. We obtained pooled estimates of sensitivity, specificity, and summary receiver operating characteristic curves (SROC). A total of 10 studies that included 669 patients who fulfilled all of the inclusion criteria were considered for inclusion in the analysis. The pooled sensitivities of EUS, ERCP, and EUS plus ERCP were 76.7, 57.9, and 79.9 %, respectively. The pooled specificities were 91.7, 90.6, and 94.2 %, respectively. The *Q index estimates were 0.828, 0.862, and 0.896, respectively. The *Q indices for EUS and EUS plus ERCP were significantly higher compared with ERCP (P = 0.010 and 0.008, respectively). Our meta-analysis showed that ERCP plus EUS was associated with a high diagnostic value for the detection of pancreatic neoplasms compared with ERCP and EUS alone.

MSX2 in pancreatic tumor development and its clinical application for the diagnosis of pancreatic ductal adenocarcinoma

MSX2, a member of the homeobox genes family, is demonstrated to be the downstream target for ras signaling pathway and is expressed in a variety of carcinoma cells, suggesting its relevance to the development of ductal pancreatic tumors since pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary-mucinous neoplasia (IPMN) harbor frequent K-ras gene mutations. Recent studies revealed the roles of MSX2 in the development of carcinoma of various origins including pancreas. Among gastrointestinal tumors, PDAC is one of the most malignant. PDAC progresses rapidly to develop metastatic lesions, frequently by the time of diagnosis, and these tumors are usually resistant to conventional chemotherapy and radiation therapy. The molecular mechanisms regulating the aggressive behavior of PDAC still remain to be clarified. On the other hand, IPMN of the pancreas is distinct from PDAC because of its intraductal growth in the main pancreatic duct or secondary branches with rare invasion and metastasis to distant organs. However, recent evidence indicated that once IPMN showed stromal invasion, it progresses like PDAC. Therefore, it is important to determin how IPMN progresses to malignant phenotype. In this review, we focus on the involvement of MSX2 in the enhancement of malignant behavior in PDAC and IPMN, and further highlight the clinical approach to differentiate PDAC from chronic pancreatitis by evaluating MSX2 expression level.

Pancreatic Cystic Tumors of Mucinous Type

This article presents the clinicopathologic characteristics and differential features of pancreatic mucinous tumors. These tumors, which correspond to the most frequent cystic neoplasms, are encountered with increasing frequency. They comprise the mucinous cystic neoplasms and the intraductal papillary mucinous neoplasms. These tumors are known to progress from dysplasia to invasive carcinoma. Thus, it appears important to distinguish them from other cystic neoplasms and non-neoplastic cysts.

The difference in the capability of delineation between convex and radial arrayed echoendoscope for pancreas and biliary tract; case reports from the standpoint of both convex and radial arrayed echoendoscope

Endoscopic ultrasound (EUS) is useful in obtaining not only high-resolution images of organs and surrounding tissue but also the tissue itself for histopathological diagnosis using fine needle aspiration. Currently, there are two types of EUS available for use: radial and convex arrayed EUS. Each type of EUS has its own advantages and disadvantages. Because radial arrayed EUS can obtain 360 degree images, it is easy to see surrounding organs and vessels. In addition, a single longitudinal image of the pancreas, gallbladder and bile duct is easy to obtain. For this reason, radial arrayed EUS is highly effective in diagnostic examinations. In contrast, while scanning range of convex arrayed EUS limited to 180 degrees, it has the advantage of being able to obtain tissue samples. Additionally while using convex arrayed EUS, the upper part of the bile duct and neck of the pancreas are easily seen beyond the portal vein. It is important to understand the characteristics of each EUS in order to select the most suitable EUS technique for diagnostic assessment.

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±16.8mm (5-50mm) and the diameter of the MPD was 6mm 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.

Intraductal papillary mucinous neoplasms of the pancreas showing fistula formation into other organs

BACKGROUND

This study assessed the mechanism of fistula formation in intraductal papillary mucinous neoplasm (IPMN) of the pancreas.

METHODS

A total of 274 patients with IPMN who had been diagnosed by endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography (EUS) at our center were enrolled. The patients with IPMN which had fistula formation into other organs were investigated retrospectively as to (1) clinical prevalence and the organs penetrated by IPMN, (2) analysis of the mechanism of fistula formation by immunohistopathological study, (3) efficacy of EUS in progression assessment, and (4) prognosis.

RESULTS

Among the subjects, fistula formation into other organs was observed in 18 patients (6.6%) and into 28 organs. There were 7 patients (39%) in whom multiple organs were penetrated. Of 16 patients who had undergone investigation of the expression of mucin markers, 94% had an intestinal-type tumor. Of 9 patients who had undergone surgery or autopsy, 67% showed mechanical penetration without invasion around the fistula. Only papillary protrusions were seen by EUS in 4 of these patients with noninvasive papillary adenocarcinoma showing mechanical penetration. All 5 patients who had pancreatic parenchymal invasion showed a mass with a mixed-echo pattern in addition to papillary protrusions shown by EUS, corresponding to colloid carcinoma.

CONCLUSIONS

There were 2 processes in the development of fistulas in IPMN. Of those patients showing fistula formation, 94% had intestinal-type IPMN, and 67% showed mechanical penetration. Delineation of a mass with the mixed-echo pattern suggested an invasive penetration due to colloid carcinoma.

Pancreatic resection guided by preoperative intraductal ultrasonography for intraductal papillary mucinous neoplasm

OBJECTIVES

Successful treatment requires reliable preoperative assessment of the highly variable extension of intraductal papillary mucinous neoplasms (IPMNs). We aimed to determine the role of intraductal ultrasonography (IDUS) in predicting the extension of IPMN, and in selecting the method of pancreatic resection and the long-term outcome after surgery.

METHODS

Randomized prospective study. Forty consecutive patients who underwent IPMN resection were included in the study. Patients were randomly assigned to an IDUS group or control group, in which IDUS was not performed.

RESULTS

Preoperative assessment by IDUS had an 85% (17 of 20) diagnostic accuracy for tumor extension of IPMN compared with 50% (10 of 20) in cases assessed by other imaging methods without IDUS (P=0.018). In 9 of 15 patients with invasive carcinoma, the tumor was located in the pancreatic head, and 11 had a main duct-type tumor. Recurrent disease was identified in 5 of 15 (33%) patients with invasive IPMN at a mean follow-up of 50 months; of them, 1 underwent preoperative IDUS and 4 were assessed by other imaging methods. None of the 25 patients with noninvasive IPMN had recurrent disease at follow-up. The overall cumulative 3-year survival rate was 79%.

CONCLUSIONS

Preoperative IDUS was useful in determining the type of surgery and the extent of resection, especially in main-duct IPMN.

Expression of MSX2 predicts malignancy of branch duct intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND

To distinguish malignant from benign branch duct (BD)-intraductal papillary mucinous neoplasm (IPMN) still remains difficult. Recently, we revealed that MSX2 was frequently expressed in pancreatic cancer and its expression was correlated with aggressive behavior of the cancer. The aim of this study was to assess the involvement of MSX2 in IPMN development and whether its expression would differentiate malignant from benign IPMN.

METHODS

Seventeen microdissected lesions and 45 IPMN tissues were used for quantitative real-time reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry, respectively. The role of MSX2 in the pancreatic duct cell was assessed by the induced expression of MSX2 in a normal human pancreatic duct epithelial cell line (HPDE).

RESULTS

Malignant IPMN expressed significantly higher levels of MSX2 mRNA than benign IPMN lesions. MSX2 protein expression was frequently found in borderline and malignant lesions (20/29, 68.9%), while its expression was seen in only one of 16 benign IPMN tissues. Univariate analysis showed that nodules of 6 mm or more and MSX2 expression were significantly correlated with the malignancy of BD-IPMN (P = 0.022 and 0.0026, respectively), and multivariate analysis revealed that only MSX2 expression was identified as an independent factor to predict malignant BD-IPMN. HPDE cells expressing MSX2 showed increased cellular proliferation compared to control cells.

CONCLUSIONS

Based on our results, MSX2 plays a pivotal role in the development of IPMN through growth stimulation of tumor cells, and its expression was identified as an independent predictive factor for malignancy of BD-IPMN.

Endoscopic diagnosis of intraductal papillary-mucinous neoplasm of the pancreas by means of peroral pancreatoscopy using a small-diameter videoscope and narrow-band imaging

BACKGROUND

Intraductal papillary-mucinous neoplasm (IPMN) is an intraductal tumor in which the mucin-producing epithelium shows proliferated papillary and a wide variety of pathological changes ranging from hyperplasia to adenocarcinoma. Therefore, it is important to determine whether an IPMN is benign or malignant. In the present study of patients with IPMN, the protrusion was observed by a peroral pancreatoscopy (PPS) using a small-diameter videoscope and narrow-band imaging (NBI). We carried out the differential diagnosis of benign lesion to malignant lesion.

METHODS

Between April 2003 and May 2009, PPS using a small-diameter videoscope by means of NBI was carried out on 21 hospitalized patients with IPMN (10 cases of adenocarcinoma, 11 cases of adenoma or hyperplasia; 14 males and seven females, with a mean age of 69.4 years).

RESULTS

Fifteen focal lesions of the 16 cases in the head of the pancreas (93.7%) and four focal lesions of the five cases in the pancreatic body (80%) were observable, whereas two lesions (adenocarcinoma in the pancreatic body, and adenoma in the uncus of pancreas) were not observable. Endoscopically, seven cases were classified as villous type and two cases as vegetative type, and nine cases were diagnosed as adenocarcinoma. Ten cases with sessile type or semipedunculated type were diagnosed as adenoma or hyperplasia. Vascular patterns and protrusions were detected more clearly in the NBI images than under white light observation.

CONCLUSIONS

When combined with a videoscope and NBI, pancreatoscopy provided a clear image and was useful for evaluating whether the IPMN was benign or malignant.

Patient- and cyst-related factors for improved prediction of malignancy within cystic lesions of the pancreas

BACKGROUND AND AIMS

Early diagnosis of cancer in pancreatic cysts is important for timely referral to surgery. The aim of this study was to develop a predictive model for pancreatic cyst malignancy to improve patient selection for surgical resection.

METHODS

We performed retrospective analyses of endoscopic ultrasound (EUS) and pathology databases identifying pancreatic cysts with available final pathological diagnoses. Main-duct intraductal papillary mucinous neoplasms (IPMNs) were excluded due to the clear indication for surgery. Patient demographics and symptoms, cyst morphology, and cyst fluid characteristics were studied as candidate risk factors for malignancy.

RESULTS

270 patients with pancreatic cysts were identified and analyzed (41% men, mean age 61.8 years). Final pathological diagnoses were branch-duct IPMN (n = 118, 50% malignant), serous cystadenoma (n = 71), pseudocyst (n = 37), mucinous cyst adenoma/adenocarcinoma (n = 36), islet cell tumor (n = 4), simple cyst (n = 3), and ductal adenocarcinoma with cystic degeneration (n = 1). Optimal cut-off points for surgical resection were cyst fluid carcinoembryonic antigen (CEA) > or =3,594 ng/ml, age >50, and cyst size >1.5 cm. Cyst malignancy was independently associated with white race (OR = 4.1, p = 0.002), weight loss (OR = 3.9, p = 0.001), cyst size >1.5 cm (OR = 2.4, p = 0.012), and high CEA > or =3,594 (OR = 5.3, p = 0.04). In white patients >50 years old presenting with weight loss and cyst size >1.5 cm, the likelihood of malignancy was nearly sixfold greater than in those patients who had none of these factors (OR = 5.8, 95% CI = 2.1-16.1, p = 0.004).

CONCLUSIONS

Risk factors other than cyst size are important for determination of malignancy in pancreatic cysts. Exceptionally high cyst fluid CEA levels and certain patient-related factors may help to better predict cyst malignancy and the need for surgical treatment.

Usefulness of multidetector computed tomography for detecting protruding lesions in intraductal papillary mucinous neoplasm of the pancreas in comparison with single-detector computed tomography and endoscopic ultrasonography

OBJECTIVES

To retrospectively evaluate the usefulness of multidetector computed tomography (MDCT) with multiplanar reformations (MPRs) and curved planar reformations (CPRs) for detecting protruding lesions in intraductal papillary mucinous neoplasms of the pancreas (IPMNs) as compared with single-detector CT (SDCT) and endoscopic ultrasonography (EUS).

METHODS

Eighty-six patients with IPMNs were imaged either with SDCT (n = 52) or MDCT with MPRs/CPRs and EUS (n = 34). The diagnostic accuracy of each imaging modality for identifying protruding lesions was compared with histological samples.

RESULTS

Among the patients in whom protruding lesions were histopathologically identified, the lesions were detected in 9 of the 33 patients subjected to SDCT (51.9% accuracy), in 17 of the 25 patients subjected to MDCT with MPRs and CPRs (76.5% accuracy), and in 21 of the 25 patients subjected to EUS (70.6% accuracy). Thus, significant difference was observed between MDCT and SDCT regarding accuracy (P < 0.05); however, no significant difference was seen between MDCT and EUS. Protruding lesions of less than 10 mm in height were better visualized with MDCT (53.3%) than with SDCT (13.0%; P < 0.05).

CONCLUSIONS

Multidetector computed tomography proved more useful than SDCT and equivalent to EUS in detecting protruding lesions in IPMNs.

Management and outcomes of pancreatic cystic lesions

The management of pancreatic cystic lesions offers a challenge to clinicians. Mucinous cystic lesions pose a low risk of the development of neoplasia that must be taken into account in long-term management. Although the natural history has not been well defined, it is likely that malignant change in the mucinous epithelium takes place over years, very similar to what is observed with Barrett's esophagus. The traditional therapy of mucinous cystic lesions has been surgical resection. Lesions in the head of the pancreas will require a Whipple resection whereas tail lesions are managed with a distal pancreatectomy and splenectomy. In patients at high risk for surgical resection, the risk/benefit ratio may be excessively high, not supporting the use of resection therapy. Ethanol ablation therapy has been thoroughly studied in hepatic, renal, and thyroid cysts. Epithelial ablation with ethanol appears to be highly effective and relatively safe. Recently, ethanol ablation has been evaluated in pancreatic cystic neoplasms. In macrocystic lesions between 1 and 5 cm, ethanol lavage will result in epithelial ablation and cyst resolution in a high percentage of patients. Pancreatitis is rarely observed clinically and is not present in resection specimens. A randomised prospective clinical trial is currently underway.

Role of endosocopic ultrasound in the diagnosis of cystic tumours of the pancreas

With the increased use of sophisticated imaging, cystic lesions in the pancreas are being recognized with greater frequency. Although imaging alone may not provide a specific diagnosis in many cases, a combination of imaging characteristics, clinical presentation, and additional procedures such as endoscopic ultrasound guided fine needle aspiration of cystic lesion, allows appropriate management. Cystic lesions in the pancreas can be divided pathologically into congenital cysts, pseudocysts and cystic neoplasm. At least four different types of cystic neoplasm have been described: mucinous neoplasms, intraductal papillary mucinous neoplasms, serous neoplasms and papillary cystic neoplasms The most important diagnosis is differentiating between mucinous and non-mucinous cystic lesion because of their different potential of malignancy. Endoscopic ultrasound provides the highest resolution of the pancreas and endoscopic ultrasound-fine needle aspiration can supply further diagnostic information on the basis of cytology, fluid viscosity, concentration of tumour glycoproteins, amylase level, molecular analysis that may contribute to the better clinical outcome of these neoplasms.

Ultrasonographic findings and natural history of intraductal papillary-mucinous neoplasms of the pancreas

It is clear that the prevalence of malignancy is high in the main-duct type of intraductal papillary-mucinous neoplasm (IPMN). Branch-duct IPMNs include several histologic conditions such as carcinoma, adenoma, and hyperplasia. Intraductal papillary adenocarcinoma and papillary adenoma are characterized by papillary protrusions and thick septum-like structures in dilated ducts as delineated by ultrasonography. A solid mass showing a mixedecho pattern in the pancreatic parenchyma is a characteristic finding of invasive types of IPMN. The international guidelines for the management of branch-duct IPMNs suggest that the appearance of symptoms attributable to the cyst, the presence of intramural nodules, a cyst size greater than 30 mm, and dilation of the main pancreatic duct (>6 mm) are indications for resection. Based on the relationship between the height of a papillary protrusion and the diameter of a cystic dilated branch as well as on histological findings, branch-duct IPMNs with papillary protrusions more than 10 mm in height as shown by imaging should be resected, and it is not adequate to differentiate carcinoma from other lesions based on the diameter of cystic branches alone. A follow-up study on branch-duct IPMNs revealed that most papillary protrusions showed a slow increase in size or development of lateral spread, and that there was no development of cancer with stromal invasion during an average follow-up of 46 months. Therefore, the presence of intramural nodules alone should not be an indication for surgery. Also, patients without papillary protrusions or thick septum-like structures are not immediate candidates for surgery. Invasive adenocarcinoma can develop at a pancreatic site different from the area of interest showing cystic changes, with such invasion possibly being multicentric. Therefore, in patients with branch-duct IPMNs, attention should be paid to the entire pancreas when performing follow-up examinations.

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 > or = 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.

[Intraductal papillary mucinous tumor: diagnostic and therapeutic approach]

Primary cystic pancreatic neoplasms are rare tumors, with an approximate prevalence of 10% of cystic pancreatic lesions. Most of these lesions correspond to mucinous cystic neoplasm, serous cystoadenoma and intraductal papillary mucinous tumor (IPMT). IPMT is characterized by diffuse dilatation of the main pancreatic duct and/or side branches with inner defects related to mucin or tumor, or mucin extrusion from a patent ampulla. IPMT has a low potential for malignancy, with a low growth rate, a low rate of metastatic spread and postsurgical recurrence. Over the last few years, major advances have been made in the diagnostic and therapeutic management of this tumor.

Role of endoscopic ultrasound in the diagnosis of intraductal papillary mucinous neoplasms: correlation with surgical histopathology

BACKGROUND & AIMS

Intraductal papillary mucinous neoplasms (IPMNs) are precancerous tumors characterized by dilation of the main pancreatic duct, its side branches, or both. The purpose of this study was to evaluate the role of endoscopic ultrasound (EUS) in differentiating benign and malignant IPMNs.

METHODS

We identified all patients between July 1996-November 2005 who underwent preoperative EUS for IPMNs. Malignancy was defined as the presence of invasive carcinoma; all other neoplasms were considered benign. The results of EUS and EUS-guided fine-needle aspiration (EUS-FNA) were compared with corresponding histopathology.

RESULTS

Seventy-four patients (38 male; mean age, 65 years) with 21 (28%) malignant and 53 (72%) benign IPMNs were identified. Sixty-five (88%) underwent EUS-FNA. Compared with benign tumors, patients with malignant IPMNs were more likely to be older (P = .011), present with jaundice (P = .03) or weight loss (P = .03), and have EUS features of a dilated main pancreatic duct (P = .0001), solid lesion (P = .0001), pancreatic ductal filling defects (P = .03), or thickened septa within any cyst (P = .02). The sensitivity, specificity, and accuracy of EUS-FNA for the diagnosis of malignancy were 75% (95% confidence interval [CI], 53%-89%), 91% (95% CI, 79%-97%), and 86% (95% CI, 76%-93%), respectively. Cyst or pancreatic duct fluid carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 did not differ between groups.

CONCLUSIONS

Older age, jaundice and weight loss, and EUS features of a solid lesion, dilated main pancreatic duct, ductal filling defects, and thickened septa are predictive of malignancy in patients with IPMNs. EUS-FNA cytology is helpful, but cyst fluid CEA and CA 19-9 are of limited value to differentiate malignant from benign IPMNs.

Pancreatic imaging: current and emerging technologies

This review discusses the current imaging modalities for the diagnosis and staging of solid and cystic pancreatic lesions and for the assessment of acute and chronic pancreatitis, and the future role of emerging technologies in the management of pancreatic diseases. Multidetector row spiral computed tomography is superior to conventional single-detector row spiral computed tomography in the detection and staging of pancreatic adenocarcinoma. Positron emission tomography is a sensitive but relatively nonspecific diagnostic modality. Positron emission tomography-computed tomography fusion may improve the staging accuracy for pancreatic cancer. Echo-enhanced ultrasound may have an emerging role in evaluating pancreatic masses. Endoscopic ultrasound with fine needle aspiration for cytology is the single best method for diagnosis and staging of nonmetastatic pancreatic cancer with a high accuracy for determining tumor resectability. In acute pancreatitis, a modification of the standard computed tomography severity index, which places greater emphasis on extrapancreatic complications, has shown superior correlation with various patient outcome measures. Endoscopic retrograde cholangiopancreatography is still the test of choice for morphological evaluation of chronic pancreatitis, whereas magnetic resonance cholangiopancreatography offers a noninvasive alternative in selected patients. Endoscopic ultrasound can be useful for detecting early chronic pancreatitis. Secretin-stimulated imaging techniques may eventually provide a noninvasive method of reliably assessing pancreatic exocrine function.

[Endoscopic ultrasonography (EUS) in preoperative localization of neuroendocrine tumors (NET) of the pancreas]

BACKGROUND

Preoperative localization of pancreatic neuroendocrine tumours (NET) is usually very difficult. Noninvasive, imaging tests, such as abdominal ultrasound, CT or MRI are not sensitive enough as well as selective angiography. The aim of the study was to clarify the usefulness of the EUS in preoperative localization of the pancreatic NET.

METHODS

From September 1998 March 2005, EUS was performed in 1600 patients. Among them, in 10 (0.7%), this examination was carried out due to previous biochemical tests, which diagnosed the pancreatic NET. We studied the location, the size and echo-pattern of the neoplasm. The results were compared with operation and histology or EUS- FNA guided pancreatic biopsy in 9/10 patients. All EUS examinations were performed using Olympus GIF-130 videoecho-endoscope with 7,5 /12MHz switchable radial probe.

RESULTS

EUS correctly localized the pancreatic NET in 7/8 cases, (sensitivity:87.5%). In 2 patients, EUS accurately exclouded pancreatic NET. There were no false positive findings (specificity 100%). Six tumours were benign (75%), and two were malign (25%). We localized 6 insulinomas and single pancreatic carcinoid tumour. The median tumour size detected by EUS was 21mm.

CONCLUSION

EUS is highly accurate in preoperative localization of the pancreatic NET-s and We confirmed it in our study. EUS presents the method of choice for preoperative localization of the pancreatic NET.

Fine-needle aspiration cytology of intraductal papillary mucinous tumors of the pancreas

BACKGROUND

Intraductal papillary mucinous tumors (IPMT) account for 5% of pancreatic neoplasms. Preoperative identification is important because of their frequent multifocal or diffuse involvement in pancreatic ducts, which makes extensive surgery necessary even in benign cases. To the authors' knowledge, the cytologic features of this entity in fine-needle aspiration biopsy (FNAB) specimens have seldom been described and are poorly standardized.

METHODS

Eleven consecutive cases of surgically proven IPMT with previous endoscopic ultrasonography (EUS)-guided FNAB were collected for retrospective analysis. EUS-FNAB had been performed with on-site attendance of a cytopathologist in all cases. Macroscopic and microscopic appearance of mucin, cellular type and arrangement, presence of nuclear grooves, and degree of nuclear atypia were recorded.

RESULTS

Final diagnosis was benign IPMT (B) in four cases, borderline IPMT (Bo) in two cases, malignant IPMT (M) in one case, and IPMT associated with invasive carcinoma (Ca) in four. Retrospective analysis found moderate to high levels of extracellular mucin in 10 of the 11 cases. The other case (one Ca) showed a small amount of thick mucin. In all cases, epithelial cells were identified, although cellularity was very low in four cases (three B and one Bo). Atypia was absent in two cases (two B) slight in two cases (two B), moderate in three cases (one Bo and two Ca), and severe in four cases (one Bo, one M, and two Ca). Mucinous epithelium was found in nine cases and nonmucinous epithelium in five cases (one Bo and four Ca). Papillary structures were observed in five cases (two Bo and three Ca), sheets in eight cases (four B, one Bo, one M, and two Ca), single atypical cells in five cases (one Bo and four Ca), irregular clusters in three cases (one Bo and two Ca), and nuclear grooves in two cases (one B and one Bo).

CONCLUSIONS

The most common features of IPMT were extracellular mucin and sheets of mucinous epithelium. Papillae and nuclear grooves were not consistently found. Nonmucinous epithelium, severe atypia, single atypical cells, and irregular clusters indicated a high probability of malignant transformation. Even in the absence of atypia, a clinically significant diagnostic orientation can be established in most cases on the basis of the characteristic cytologic picture.

Mode of progression of intraductal papillary-mucinous tumor of the pancreas: analysis of patients with follow-up by EUS

BACKGROUND

We investigated the mode of progression of intraductal papillary-mucinous neoplasm of the pancreas (IPMN) in patients who underwent follow-up in order to elucidate the characteristics of malignancy and to establish an effective treatment strategy.

METHODS

Fifty-one patients with IPMN (branch-duct type, 47; main-duct type, 4) who had undergone follow-up study by endoscopic ultrasonography (EUS) were included (mean follow-up duration, 41.0+/-32.3 months; average number of EUS examinations performed during follow-up, 4.4). Chronological changes in EUS findings and histological findings of resected specimens were evaluated.

RESULTS

Of the patients with the branch-duct type, only 2% showed enlargement of the dilated branches. In the main-duct-type group, an increase in size of the main pancreatic duct (MPD) was observed in 75% of the patients. In 14 patients with papillary protrusions, an increase in size and lateral spread was observed in 71% and 43%, respectively. No patients developed invasive cancer. In 15 patients who had thick septum-like structures (TSS), the development of papillary protrusions and that of invasive cancer were observed in 53% and 13%, respectively. Twenty-nine patients who had thin septum-like structures showed no change. Two patients with dense multilocular large cysts and TSS developed invasive cancer without change in the cystic lesions. One patient developed carcinoma with multifocal stromal invasion.

CONCLUSIONS

Patients with branch-duct type IPMNs without papillary protrusions or TSS are not immediate candidates for surgery. Those who have small papillary protrusions have a benign course. It is recommended that patients with the large branch-duct type with TSS should undergo surgery. Attention should be paid to the entire pancreas when performing follow-up examinations in patients with branch-duct type IPMN, as invasive ductal adenocarcinoma can develop at a site in the pancreas different from that of the IPMN.

Evaluation and management of cystic pancreatic tumors: emphasis on the role of EUS FNA

Cystic lesions of the pancreas are increasingly recognized and usually represent pseudocysts or cystic pancreatic tumors (CPTs), but also include congenital cysts, acquired cysts, extrapancreatic cysts, or cystic degeneration of solid tumors. It is important to distinguish CPT lesions given their varied prognosis and therapy. Mucinous varieties of CPTs (mucinous cystic neoplasms and intraductal papillary mucinous tumors) are premalignant or malignant, and surgical resection is generally recommended in good operative candidates. In contrast, nonmucinous CPTs include serous cystadenomas with a very low malignant potential, or pseudocysts, which are always benign. As a result, nonmucinous CPTs are generally resected only when inducing symptoms or complications. Review of the clinical, imaging, laboratory, and pathology information may clarify the specific tumor type. The relatively limited accuracy of any one modality requires that we consider the combined results when making management decisions.

Predictive factors for malignancy in intraductal papillary-mucinous tumours of the pancreas

BACKGROUND

Preoperative assessment of the likelihood of malignancy in intraductal papillary-mucinous tumour (IPMT) of the pancreas is often difficult. Predictive factors for malignancy and invasive carcinoma in IPMT were analysed.

METHODS

Sixty-two patients with IPMT underwent surgical treatment, with histological confirmation of adenoma in 28, carcinoma in situ in 14 and invasive carcinoma in 20. Tumours were of the main duct type in 14 patients, branch duct type in 32, and combined type in 16. A multivariate analysis of 17 potential predictive factors, including preoperative clinical and imaging findings, was conducted.

RESULTS

Multivariate analysis identified two independent predictive factors for malignancy: mural nodules and main pancreatic duct diameter of 7 mm or more. Mural nodules in the main duct or combined type, and mural nodules and tumour diameter of 30 mm or more in the branch duct type were particularly indicative of malignancy. Mural nodules, jaundice and main duct or combined type were predictors of invasive carcinoma in the multivariate analysis.

CONCLUSION

The above factors should be considered in the diagnosis of IPMT to facilitate appropriate management.

EUS in the evaluation of pancreatic cystic lesions

BACKGROUND

The differential diagnosis in pancreatic cystic lesions is often difficult despite the availability of various modern imaging modalities. This study assessed the role of EUS in the following: (1) discrimination of pseudocysts from pancreatic cystic tumors, (2) differential diagnosis between serous cystadenoma and mucinous cystic tumor, and (3) prediction of accompanying malignancy in intraductal papillary mucinous tumor.

METHODS

EUS findings in 75 patients with pancreatic cystic lesions (58 cystic tumors, 17 pseudocysts) were evaluated. In the comparison of pseudocysts and cystic tumors, the latter included intraductal papillary mucinous tumor, mucinous cystic tumors, and serous cystadenomas, but not solid-pseudopapillary tumors.

RESULTS

In univariate analysis, pseudocysts exhibited echogenic debris and parenchymal changes more often than cystic tumors did (respectively, 29% vs. 6%, p < 0.05; and 65% vs. 4%, p < 0.001). In contrast, septa and mural nodules were found more frequently in cystic tumors than pseudocysts (respectively, 69% vs. 12%, p < 0.001; 56% vs. 12%, p < 0.01). Multivariate analysis revealed that parenchymal changes (odds ratio [OR] = 83.59; p < 0.01); septa (OR = 30.75; p < 0.05); and mural nodules (OR = 21.38; p < 0.05) were independent predictors of differentiation between pseudocysts and cystic tumors. Serous cystadenoma exhibited diverse EUS features, as well as a honeycomb appearance. Mural nodules were found more often in mucinous cystic tumors than in serous cystadenomas (p < 0.05). There were no factors that predicted malignancy in intraductal papillary mucinous tumor.

CONCLUSIONS

EUS is a useful complementary imaging method for differentiation of pancreatic cystic lesions.

The role of ultrasound in biliary and pancreatic diseases

The possibilities and the limits of transabdominal ultrasonography (US) in the diagnosis of bilio-pancreatic diseases are reviewed here in the light of the last 10 years' research. US remains the method of choice for the diagnosis of gallstones and is generally accepted as an initial imaging technique in gallstone complications, such as acute cholecystitis. Moreover the method can be useful for the detection of the biliary complications after laparoscopic cholecystectomy and after liver transplantation. US is still considered the first diagnostic procedure when stones are suspected in the common bile duct. The use of color Doppler can provide a differential diagnosis of gallbladder cancer with respect to other benign inflammatory or polypoid lesions. Color Doppler US allows to detect vascular complications of acute pancreatitis such as pseudoaneurysms. US is still considered useful for the initial screening of the pancreatic cancer. However, for staging other imaging techniques must be employed. With US useful informations are obtained in the diagnosis of cystic tumors of the pancreas and of pancreatic metastases. US is generally of little use for the diagnosis of endocrine tumors.

Invasive cancer and survival of intraductal papillary mucinous tumors of the pancreas

OBJECTIVES

Intraductal papillary mucinous tumor (IPMT) is frequently associated with pancreatic cancer. We hypothesized that IPMT progresses to invasive cancer with K-ras mutations as an early event, and that invasive cancer affects survival. We compared survival after resection and determined whether K-ras mutations predicted survival in IPMT patients without or with invasive cancer.

METHODS

Records of 47 patients with IPMT who were seen between 1983 and 1998 were reviewed retrospectively in 15 cases and prospectively in 32. All histological material was reviewed to confirm the diagnosis of IPMT and to assess invasion. Kaplan-Meier survival curves were analyzed by the log-rank test. The chi2 test was used for differences in K-ras between groups.

RESULTS

There were 30 men and 17 women, with a mean age of 65 yr (range 36-90 yr). Of the patients, 26 had IPMT without invasive cancer and 19 had IPMT with invasion. Tissue diagnosis was available in 45 patients. K-ras was analyzed in 40 patients. Mutations were present in 15 of 23 patients (65%) without invasive cancer and in 14 of 17 patients (82%) with invasive cancer (p = ns). At 2.5 yr, the overall cumulative survival of IPMT patients without invasive cancer was 94% compared to 24% of patients with invasive cancer (p < 0.001). The 5-yr survival of IPMT patients without invasive cancer was 94%. K-ras mutations did not correlate with survival.

CONCLUSIONS

Invasive cancer in IPMT reduces the 2.5-yr survival after surgery from 93% to 24%. K-ras mutations occur before invasive cancer, and do not predict postoperative survival.

Wirsung and Santorini: the men behind the ducts

During the 16th and 17th centuries, several important discoveries were accomplished by anatomists whose contribution has enlightened the most important anatomic structures of the pancreas. Following the earliest discoveries, researchers of several medical specialities further investigated the ductal pancreatic system. The accessory pancreatic duct with its minor papilla, the main pancreatic duct and the papilla major along with the confluence of the main pancreatic duct with the bile duct and pancreas divisum, have been the objects of interest of several personalities of the medical history. Eponyms in pancreatic anatomy were given to remember some of them, although anatomical misattributions are frequent and controversial. The aim of the authors was to dedicate a small tribute to the researchers who have written, during the last 500 years, important chapters of the medical history and who dedicated their lives to study the pancreatic ducts and their duodenal endings. Furthermore, a brief outlook was dedicated to the impact of anatomic variations and of embryologic anomalies of the pancreatic ducts in our clinical practice and in our actual understanding of duct-related diseases. The authors are confident that the genial curiosity of few extraordinary personalities of the past and the opportunities provided by modern technology continue to play a major role that may finally add wisdom to decision-making in dealing with duct-related biliopancreatic diseases and safety to diagnostic and therapeutic procedures employed.

Diagnostic significance of high mobility group I(Y) protein expression in intraductal papillary mucinous tumors of the pancreas

INTRODUCTION

Overexpression of the high mobility group I(Y), [HMGI(Y)], gene/proteins has been demonstrated in many types of human malignancies, suggesting that HMGI(Y) may play a vital role in the oncogenic transformation of cells.

AIMS

To analyze HMGI(Y) expression in intraductal papillary mucinous tumor (IPMT) of the pancreas to verify whether determination of the HMGI(Y) expression level could provide any diagnostic advantages in the pathological diagnosis of IPMT.

METHODOLOGY

Thirty-three different lesions from 25 patients with IPMT, including 20 with mild dysplasia, 7 with moderate dysplasia, and 6 with carcinoma, were analyzed immunohistochemically with use of an HMGI(Y)-specific antibody.

RESULTS

Immunohistochemical analysis revealed that, although no significant immunoreactivity was found in cases of normal pancreatic duct or mild dysplasia, 28.6% (2/7) of moderate dysplasia showed multifocal immunoreactivity with moderate intensity. In contrast, in 50% (3/6) of the cases of carcinoma, intense multifocal or diffuse immunoreactivity occurred, almost equivalent to that observed in cases of duct cell carcinoma, whereas in the remaining 3 cases of carcinoma only a faint focal immunoreactivity occurred. Histologic examination revealed that these HMGI(Y)-positive carcinomas had an invasive growth pattern, whereas the HMGI(Y)-negative carcinomas were either carcinomas in situ or tumors with minimal invasion. Thus, an increased expression level of HMGI(Y) proteins was closely associated with the malignant phenotype in IPMT.

CONCLUSION

On the basis of these findings, we propose that HMGI(Y) proteins could play an important role(s) in a multistage process of carcinogenesis of IPMT and that the HMGI(Y) protein level could serve as a potential diagnostic marker, which may enable the identification of tumor cells with potential to be biologically malignant.