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

[Differentiated therapy for intraductal papillary mucinous neoplasms]

Intraductal papillary mucinous neoplasms (IPMN) of the pancreas are of increasing interest in the field of pancreatic surgery ever since their first description as an individual pancreatic tumor entity in 1982. The decision for surgical or conservative management is based on the adenoma-carcinoma sequence and the differentiation into main-duct or branch-duct IPMN. Invasive IPMN forms (carcinoma in situ and invasive carcinoma) and in particular noninvasive IPMNs (adenoma and borderline tumors) reveal significantly better survival rates than ductal adenocarcinoma of the pancreas.

Asymptomatic pancreatic cystic neoplasm: a cost-effectiveness analysis of different strategies of management

BACKGROUND

Optimal management of asymptomatic pancreatic cystic neoplasm is not known.

OBJECTIVE

In a decision analysis, the cost-effectiveness of different strategies for managing solitary, asymptomatic pancreatic cystic neoplasm were compared.

INTERVENTION

Three strategies were examined in a Markov model with a third-party-payer perspective. In strategy I, the natural history of the lesion was followed without any specific intervention. In strategy II, an aggressive surgical approach was considered in that all patients were considered for resection. In strategy III, an initial EUS-guided FNA with cyst fluid analysis was performed for risk stratification, and patients with mucinous cysts were considered for resection. Transitional probabilities, discounted cost, and utility values to estimate quality-adjusted life years were obtained from published information. An operability risk score based on patient age, comorbidity, and size and location of the cyst was developed to estimate the probability of surgical resection.

RESULTS

In the baseline analysis, strategy III yielded the highest quality-adjusted life years with an acceptable incremental cost-effectiveness ratio. In a Monte Carlo analysis, the relative risk of patients developing unresectable pancreatic cancer was decreased in strategy III compared to the other strategies. Although threshold analyses identified few important parameters influencing the conclusion of the analysis, operability risk score was the critical determinant of the optimal management strategy.

LIMITATIONS

Indirect costs were not considered in this analysis.

CONCLUSION

For asymptomatic patients with incidental solitary pancreatic cystic neoplasm, a blanket policy of surgical resection for all patients cannot be justified. A strategy based on risk stratification of malignant potential by EUS-guided FNA and cyst fluid analysis is the most cost-effective strategy.

Endosonography in the management of biliopancreatic disorders

Over the past two decades, endoscopic endosonography (EUS) has evolved into an indispensible diagnostic and therapeutic utility in the diagnosis and treatment of patients with pancreatobiliary disease. In this article, we summarise its current potential and provide an update of the latest literature.

Comparative performance of MDCT and MRI with MR cholangiopancreatography in characterizing small pancreatic cysts

OBJECTIVE

The objective of our study was to compare MDCT with MRI-MR cholangiopancreatography (MRCP) in characterizing small pancreatic cysts (< or = 3 cm) and predicting aggressiveness.

MATERIALS AND METHODS

In a retrospective analysis, contrast-enhanced MDCT and MRI examinations of 30 patients with 38 pathologically confirmed small pancreatic cysts were reviewed. MDCT and MRCP studies were independently evaluated by two readers for cyst morphology, cyst characterization, and prediction of lesion aggressiveness, which included lesions with moderate-grade dysplasia, high-grade dysplasia (carcinoma in situ), and invasive carcinomas. The sensitivity of MDCT and MRI for the detection of each morphologic feature, accuracy for cyst characterization, and predictive values for aggressiveness were calculated.

RESULTS

Of 38 lesions, 14 were side-branch intraductal papillary mucinous neoplasms (IPMNs), 12 mixed IPMNs, six mucinous cystic neoplasms, and six nonneoplastic cysts. On histopathology, 26 lesions were nonaggressive (six nonneoplastic cysts, six benign mucinous cystic neoplasms, 14 low-grade dysplasias in IPMNs), whereas 12 lesions revealed aggressive biology (eight moderate-grade dysplasias, four high-grade dysplasias in IPMNs). The sensitivity of MRCP for the detection of morphologic features was better than that of MDCT, but the differences were not statistically significant (p = 0.25-1). Interreader agreement and MDCT-MRI agreement for morphologic features were good to perfect (kappa = 0.7-1). The accuracy of MDCT and MRI was higher in classifying cysts as mucinous or nonmucinous than in determining a specific diagnosis (71-84.2% vs 39.5-44.7%, respectively), whereas the accuracy of the two techniques in characterizing cysts into nonaggressive and aggressive categories was similar (MDCT vs MRI, 75-78% vs 78-86%, respectively; p > 0.05).

CONCLUSION

MRI enables more confident assessment of the morphology of small cysts than MDCT, but the accuracy of the two imaging techniques for cyst characterization is comparable. MDCT and MRI have high accuracy in classifying cysts into mucinous and nonmucinous categories and perform similarly in estimating histologic aggressiveness.

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 pathologically-confirmed 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 combined-type 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.

Main pancreatic duct intraductal papillary mucinous neoplasms: accuracy of MR imaging in differentiation between benign and malignant tumors compared with histopathologic analysis

PURPOSE

To retrospectively determine the accuracy of magnetic resonance (MR) imaging combined with MR cholangiopancreatography (CP) in differentiating benign from malignant intraductal papillary mucinous neoplasms (IPMNs) involving the main pancreatic duct (MPD), with histopathologic analysis as the reference standard.

MATERIALS AND METHODS

The informed consent requirement was waived for this institutional review board-approved study. A total of 51 patients with histopathologically proved IPMNs (MPD IPMN, n = 29; mixed type IPMN, n = 22), underwent MR imaging, MR CP, and surgery, with a mean interval of 2.6 months between MR examination and surgery. Qualitative image analysis included assessment of the site of MPD dilatation (head of the pancreas, body and/or tail of the pancreas, or diffuse), presence or absence of duct wall nodules, and contrast enhancement of the MPD walls. Quantitative image analysis included measurement of the maximum diameter of the MPD. A comparison of adenomas and borderline IPMNs with cancerous IPMNs was performed with the Student t test or the Mann-Whitney U test for continuous variables.

RESULTS

At histopathologic analysis, 27 IPMNs were classified as carcinomas; 13, as borderline tumors; and 11, as adenomas. MPD wall nodules were observed in 16 carcinomas involving the MPD and one adenoma or borderline neoplasm (P < .00001). Duct wall enhancement was observed in 20 MPD or mixed type carcinomas and five adenomas or borderline neoplasms (P = .0001). The median maximal diameter of the MPD was 18 mm in malignant MPD or mixed type IPMNs and 11 mm in benign borderline IPMNs (P = .038). No significant difference in the overall 5-year survival rate of patients with MPD IPMNs and those with mixed type IPMNs was observed (P = .813).

CONCLUSION

Duct wall nodules and enhancement of the MPD walls are signs of malignant MPD or mixed type IPMNs.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.2531080604/-/DC1.

Clinical fate of branch duct and mixed forms of intraductal papillary mucinous neoplasia of the pancreas

AIMS

The aim of the present study was to assess the clinical fate of, and to gain new insights into, branch duct and mixed (predominantly main duct type) forms of intraductal papillary mucinous neoplasia of the pancreas (IPMN).

METHODS

During a 17-year period, 99 successive IPMN patients (52 men, 47 women; mean age, 64 years) were included and divided into two groups for further comparison: one group had branch duct IPMN, whereas the other had mixed IPMN.

RESULTS

Patients from the mixed IPMN group (n = 52) displayed a greater rate of symptoms (83% vs 55%, P = 0.004), pancreatic resection (67% vs 38%, P = 0.007), malignancy (35% vs 13%, P = 0.017) and death (15% vs 4%, P = 0.09) than those from the branch duct IPMN group. A 38-month follow up of non-operated, symptom-free patients confirmed that more than 85% of branch duct IPMN patients were asymptomatic without evidence of malignancy. Borderline lesions and carcinoma are found in up to 50% of symptomatic resected branch duct IPMN cases.

CONCLUSION

Patients with the mixed form of IPMN as well as with symptomatic branch duct IPMN should require pancreatic resection because of symptoms and the risk for malignancy. In silent branch duct IPMN without radiological signs of malignancy, a non-operative watch-and-wait strategy can be discussed.

Experience of limited pancreatic head resection for management of branch duct intraductal papillary mucinous neoplasm in a single center

AIM: To share our surgical experience and the outcome of limited pancreatic head resection for the management of branch duct intraductal papillary mucinous neoplasm (IPMN).

METHODS: Between May 2005 and February 2008, nine limited pancreatic head resections (LPHR) were performed for IPMN of the pancreatic head. We reviewed the nine patients, retrospectively.

RESULTS: Tumor was located in the uncinate process of the pancreas in all nine patients. Three patients had stents inserted in the main pancreatic duct due to injury. The mean size of tumor was 28.4 mm. Postoperative complications were found in five patients: 3 pancreatic leakages, a pancreatitis, and a duodenal stricture. Pancreatic leakages were improved by external drainage. No perioperative mortality was observed and all patients are recorded alive during the mean follow-up period of 17.2 mo.

CONCLUSION: In selected patients after careful evaluation, LPHR can be used for the treatment of branch duct type IPMN. In order to avoid pancreatic ductal injury, pre- and intra-operative definite localization and careful operative techniques are required.

Intraductal papillary mucinous neoplasms of the pancreas: differentiation of malignant and benign tumors by endoscopic ultrasound findings of mural nodules

BACKGROUND AND AIM

Intraductal papillary mucinous neoplasms (IPMNs)have a wide pathologic spectrum and it is difficult to differentiate malignant from benign tumors. The aim of this study was to identify predictors of malignancy using contrast-enhanced endoscopic ultrasound (CE-EUS).

SUBJECTS AND METHODS

In our institute, main duct type and mixed type IPMNs, branch duct type IPMNs with mural nodules, and IPMNs with coexistent invasive ductal cancer were indications for surgery. Eighty-seven IPMNs (14 main duct, 25 mixed, and 48 branch duct type) were resected and CE-EUS findings were compared with pathologic findings. Twelve clinicopathological variables and CE-EUS morphologic findings were assessed.Mural nodules defined as blood flow supplied protrusions were classified into 4 types: type I: low papillary nodule, type II: polypoid nodule, type III:papillary nodule, and type IV: invasive nodule.

RESULTS

Forty-two, 26, 16, and 3 were pathologically diagnosed as adenoma,noninvasive carcinoma, invasive IPMNs, and coexistent invasive ductal cancer, respectively. Multivariable logistic regression analysis showed that types III/IV mural nodule (odds ratio = 10.8; 95% confidential intervals = 2.75-56.1) and symptomatic IPMNs (odds ratio = 4.31; 95% confidential intervals = 1.37-14.7) were significant for malignancy. For mural nodule diameter, invasive IPMNs were significantly larger, but types III and IV mural nodules were more frequently associated with malignancy, particularly invasive cancer, at 88.9% and 91.7%, respectively. The diagnosis of IPMNs with types III or IV mural nodule as malignant resulted in a sensitivity of 60%, specificity of 92.9%, and accuracy of 75.9%.

CONCLUSIONS

In conclusion, new morphologic criteria were useful to identify the malignant potentials of IPMNs.

Awareness of guidelines and trends in the management of suspected pancreatic cystic neoplasms: survey results among general gastroenterologists and EUS specialists

BACKGROUND

Although pancreatic cystic neoplasms are widely recognized, practice habits among physicians and awareness of consensus guidelines are currently unknown.

OBJECTIVES

To assess the awareness of guidelines and describe variability in practice habits among 2 groups: (1) "general group" of gastroenterologists and surgeons and (2) "EUS group" of specialists in EUS.

DESIGN

An online survey was sent to randomly selected gastroenterologists and surgeons and e-mailed to members of the American Society for Gastrointestinal Endoscopy (ASGE) Special Interest Group in EUS (EUS-SIG).

RESULTS

Response rate for the general group was 8.8% (220/2500) and 9.7% for the EUS group (42/431). EUS specialists were mostly in academic practice (66.7% vs 36.3%, P < .001) and reported seeing 21 to 50 cysts per year (54.8% vs 12.3%, P < .001). The majority of the general group (64.1%) was unaware of any published practice guidelines, compared with 33.3% of EUS specialists (P < .001). Awareness of ASGE guidelines was more frequently reported than other guidelines in both groups and yet was still <50% for each group. Both demonstrated moderate consistency with the International Association of Pancreatology guidelines, appropriately answering 66.7% of the questions. For 9-mm lesions, only 25% of the questions were correctly answered in each group. EUS specialists were less likely to refer main-duct intraductal papillary mucinous neoplasms (IPMN) for surgery and more likely to opt for EUS-guided FNA (compared with high-resolution CT, MRCP, or surgery) for 9-mm, 22-mm, and 34-mm branch-duct IPMNs (P </= .001).

LIMITATIONS

Low response rate and recall bias.

CONCLUSIONS

Awareness of practice guidelines about the management of suspected pancreatic cystic neoplasms is lower among general GI physicians compared with EUS specialists. Among all physicians, the greatest variability in practice is in small (<1 cm) lesions.

Pancreatic cysts: pathologic classification, differential diagnosis, and clinical implications

CONTEXT

Cystic lesions of the pancreas are being recognized with increasing frequency and have become a more common finding in clinical practice because of the widespread use of advanced imaging modalities and the sharp drop in the mortality rate of pancreatic surgery. Consequently, in the past 2 decades, the nature of many cystic tumors in this organ has been better characterized, and significant developments have taken place in the classification and in our understanding of pancreatic cystic lesions.

OBJECTIVE

To provide an overview of the current concepts in classification, differential diagnosis, and clinical/biologic behavior of pancreatic cystic tumors.

DATA SOURCES

The authors' personal experience, based on institutional and consultation materials, combined with an analysis of the literature.

CONCLUSIONS

In contrast to solid tumors, most of which are invasive ductal adenocarcinomas with dismal prognosis, cystic lesions of the pancreas are often either benign or low-grade indolent neoplasia. However, those that are mucinous, namely, intraductal papillary mucinous neoplasms and mucinous cystic neoplasms, constitute an important category because they have well-established malignant potential, representing an adenoma-carcinoma sequence. Those that are nonmucinous such as serous tumors, congenital cysts, lymphoepithelial cysts, and squamoid cyst of pancreatic ducts have no malignant potential. Only rare nonmucinous cystic tumors that occur as a result of degenerative/necrotic changes in otherwise solid neoplasia, such as cystic ductal adenocarcinomas, cystic pancreatic endocrine neoplasia, and solid-pseudopapillary neoplasm, are also malignant and have variable degrees of aggressiveness.

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.

Branch duct intraductal papillary mucinous neoplasms in a retrospective series of 190 patients

Background

A consensus conference has recommended close observation of branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) smaller than 30 mm, without symptoms or mural nodules. This study investigated whether these recommendations could be validated in a single-centre experience of BD-IPMNs.

Methods

Some 190 patients with radiological imaging or histological findings consistent with BD-IPMN were enrolled between 1998 and 2005. Those with less than 6 months' follow-up and no histological confirmation were excluded.

Results

BD-IPMN was diagnosed by computed tomography and pancreatography in 105 patients and pathologically in 85. Eighteen patients had adenoma, 53 borderline malignancy, five carcinoma in situ and nine invasive carcinoma. Findings associated with malignancy were the presence of radiologically suspicious features (P &lt; 0·001) and a cyst size of at least 30 mm (P = 0·001). Had consensus guidelines been applied, 54 patients would have undergone pancreatic resection, whereas only 28 of these patients actually had a resection; 12 of the latter patients had a malignancy compared with none of the 26 patients who were treated conservatively.

Conclusion

A simple increase in cyst size is not a reliable predictor of malignancy. Observation is recommended for patients with a BD-IPMN smaller than 30 mm showing no suspicious features on imaging.

[Limited pancreatic resections for intraductal papillary mucinous neoplasm]

INTRODUCTION

For non-invasive intraductal papillary and mucinous neoplasm (IPMN) with limited extent, pancreaticoduodenectomy (PD) or distal pancreatectomy (DP) seem excessive due to the risk of pancreatic insufficiency. Enucleation (EN) or medial pancreatectomy (MP) are not commonly performed for IPMN. The aim of this study was to evaluate the feasibility and results of EN and MP for non-invasive IPMN.

PATIENTS AND METHODS

Of 249 patients with IPMN, we attempted a limited resection in 50 (20%) EN (n=31) or MP (n=20) with routine intra-operative frozen section pathology. One attempted EN was converted to MP. Indications for surgery were pain/pancreatitis (44%), suspicion of main duct involvement (28%), mural nodules in branch duct (14%), branch duct>30 mm (8%) or suspicion of mucinous cystadenoma (6%). Follow-up clinical assessment and MRI were performed on a yearly basis.

RESULTS

Of the 31 attempted enucleations, 5 (13%) were immediately converted (4 PD, 1 MP) due to technical reasons (n=3) or due to findings on frozen section (n=2). At definitive pathological examination (accuracy of frozen sectioning=98%), branch ducts were involved by mild (n=21), moderate (n=7) or high grade dysplasia (n=2). One patient underwent a double EN. Of 20 attempted medial pancreatectomies, 8 (40%) required additional segmental resection due to significant IPMN lesions at pancreatic margins; 3 of the additional resection margins were tumor-free, and 5 were involved by IPMN (4 conversions to PD or DP, one contra-indication to PD). Overall, 49 pancreatic margins were analyzed by frozen sectioning with 98% accuracy. Resected specimens of 16 MP showed involvement by mild (n=7), moderate (n=7) or high grade dysplasia (n=2). There was no postoperative mortality. Median length of stay was 21 and 30 days respectively after EN and MP. Pancreatic fistula rate was 54% and 81% respectively after EN and MP. Three patients underwent early re-operation for hemorrhage. Overall median follow-up was 24 months (3-121). All patients are alive, 2 patients (5%) have presented with recurrent pain and 4 have developed tumor recurrence on imaging follow-up (4/33=12%). Two patients (5%) developed de novo diabetes (one after EN combined with DP) and a third patient developed worsening of pre-existing diabetes plus exocrine insufficiency. No patient had surgery for recurrence.

CONCLUSIONS

EN and MP are feasible for non-invasive IPMN. Their significant early morbidity is counterbalanced by low rates of both long-term functional disorders and tumor recurrence.

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.

REG4 is associated with carcinogenesis in the 'intestinal' pathway of intraductal papillary mucinous neoplasms

Subclassification of intraductal papillary mucinous neoplasms of the pancreas (IPMNs), based on morphological features and immunohistochemical profiles, has been proposed. Intestinal-type IPMNs frequently show moderate to severe dysplasia. Regenerating islet-derived family, member 4 (REG4) is associated with the adenoma-carcinoma sequence in colon cancer and it is also associated with intestinal phenotype. Therefore, to identify REG4 expression in IPMNs may be helpful to detect high-grade IPMNs. We also investigated REG4 expression and CDX2 expression in IPMNs. To investigate the expressions of REG4 and CDX2 in IPMNs and in invasive ductal adenocarcinoma derived from IPMN, we used immunohistochemical staining and microdissection-based quantitative real-time reverse transcription-polymerase chain reaction. Among 125 IPMNs, 43 (34%) were positive for REG4 and most of the intestinal-type IPMNs showed its expression (35/38). The positive ratio of REG4 expression in colloid carcinoma (5/7) was significantly higher than that in tubular carcinoma (1/17; P=0.003). Most of CDX2-positive cases (31/33) expressed REG4 protein, whereas only 12 of 92 CDX2-negative cases did (P<0.001). The levels of REG4 mRNA in intestinal-type IPMN were significantly higher compared to those in gastric-type IPMN or to normal pancreatic ductal epithelium (P=0.005, P=0.004, respectively). REG4 expression was observed more frequently in borderline lesions (14/28) and carcinoma (21/45) compared to adenoma (8/52). Using the Ki-67 labeling index, REG4 expression was significantly correlated with proliferative activity in borderline lesions. We conclude that REG4 is involved in the 'intestinal' pathway of carcinogenesis in IPMN.

Multidisciplinary approach to diagnosis and management of intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms have gained recognition in recent years as premalignant precursors to pancreatic cancer that enable early detection and often are found incidentally at imaging. Accurate diagnosis and optimal, finely tuned management of these lesions are important and require collaboration across various disciplines, including radiology, endoscopy, surgery, and pathology. Several imaging modalities can visualize these lesions adequately, each with specific advantages and disadvantages. Multidetector computed tomography and magnetic resonance cholangiopancreatography are generally the first-line imaging modalities; endoscopic imaging such as endoscopic ultrasound and endoscopic retrograde cholangiopancreatography are beneficial when the former 2 modalities are equivocal. Surgical candidates generally include patients with main duct lesions or branch duct lesions greater than 3 cm or any possessing a solid component. A management algorithm indicating when surgery should be pursued is proposed. For nonsurgical and postsurgical patients, follow-up management is important to monitor growth and recurrence, and risks from repeated radiation exposure should be taken into account. Furthermore, issues of multifocality and increased predisposition of the pancreas to ductal adenocarcinoma must be addressed at follow-up evaluation. A follow-up management algorithm also is proposed in this review.

Management of mucin-producing cystic neoplasms of the pancreas

During the last decade small lesions of the pancreas have been increasingly recognized in clinical practice. Among these lesions, mucin-producing cystic neoplasms represent a recently described and unique entity among pancreatic tumors. In 1996, the World Health Organization distinguished two different types of mucinous cystic tumors: intraductal papillary mucinous neoplasms (IPMNs) of the pancreas, which are characterized by mucin production, cystic dilation of the pancreatic ducts, and intrapapillary growth, and mucinous cystic neoplasms (MCNs), which are defined by ovarian-like stroma and in most cases do not communicate with pancreatic ducts. Further, IPMNs can be subdivided into main-duct type, mixed-type, and branch-duct type tumors. Older data did not distinguish among different subsets of cystic neoplasms of the pancreas, and consequently many databases were inconsistent. Histopathologically, both IPMNs and MCNs demonstrate a wide spectrum of cellular atypia ranging from mild mucinous hyperplasia to invasive adenocarcinoma. Because mucinous cystic neoplasms of the pancreas show significant differences in clinical behavior from patient to patient, knowledge of the clinicopathologic characteristics and natural history of specific subtypes of IPMNs and MCNs has become crucial for physicians working in the field of gastroenterology. The present work offers an overview of current and generally accepted clinical guidelines for the diagnosis and treatment of IPMNs and MCNs.

Multifocal intraductal papillary mucinous neoplasm of the pancreas-A case report

Cystic neoplasms of the pancreas are relatively rare, comprising 10 percent of pancreatic cysts and only 1 percent of pancreatic cancers. Cystic neoplasms include mucinous cystic neoplasms, serous cystadenomas, papillary cystic tumors, cystic islet cell tumors and intraductal papillary mucinous neoplasms of the pancreas (IPMNs). IPMN was first described in 1982. It has been most commonly described in 60 to 70 years old males, and represents a relatively “new” but increasingly recognized disease. The improvement and widespread use of modern imaging equipments and heightened awareness of physicians contribute to the increasing incidence of IPMN. The majority of IPMNs are located in the pancreatic head (75%) while the rest involves the body/tail regions. Multifocal IPMNs have been hypothesized, but the true presence of multifocality is unknown. Here we present a 72-year-old male diagnosed with IPMN (carcinoma in situ) in the pancreatic head and a branch duct type IPMN (duct atypia) in the pancreatic body and tail. The patient underwent a Whipple intervention and a distal pancreatectomy. A three-year disease-free survival has been observed so far.

Cystic lesions and intraductal neoplasms of the pancreas

Pancreatic cystic lesions are being detected more frequently given increased use of cross-sectional imaging modalities. The most common cysts encountered are mucinous cysts, which have malignant potential. As many of these lesions are incidental findings, it is important to further evaluate them with endoscopic ultrasound-guided fine needle aspiration for diagnostic purposes and risk stratification. These cysts either require surgical resection or surveillance given the malignant risk. Mucinous cystic neoplasms should be resected. Intraductal papillary mucinous neoplasia (IPMN) has consensus-guideline indications for resection. These include main duct diameter > or = 10 mm, a branch duct size > or = 3 cm, presence of a mural nodule, or cytology suspicious for malignancy. Additionally, all symptomatic cysts, regardless of etiology, should undergo resection. Branch duct IPMN is less aggressive that the main duct variety, and may be conservatively followed. However, the development of an established indication for resection should prompt surgery. Despite generalized guidelines, decisions regarding management of pancreatic cysts should be individualized, accounting for the malignant risk of the lesion and the surgical risk of the patient.

Cystic neoplasms of the pancreas: A diagnostic challenge

Cystic neoplasms of the pancreas are increasingly recognized due to the expanding use and improved sensitivity of cross-sectional abdominal imaging. Major advances in the last decade have led to an improved understanding of the various types of cystic lesions and their biologic behavior. Despite significant improvements in imaging technology and the advent of endoscopic-ultrasound (EUS)-guided fine-needle aspiration, the diagnosis and management of pancreatic cystic lesions remains a significant clinical challenge. The first diagnostic step is to differentiate between pancreatic pseudocyst and cystic neoplasm. If a pseudocyst has been effectively excluded, the cornerstone issue is then to determine the malignant potential of the pancreatic cystic neoplasm. In the majority of cases, the correct diagnosis and successful management is based not on a single test but on incorporating data from various sources including patient history, radiologic studies, endoscopic evaluation, and cyst fluid analysis. This review will focus on describing the various types of cystic neoplasms of the pancreas, their malignant potential, and will provide the clinician with a comprehensive diagnostic approach.

Preoperative evaluation of invasive and noninvasive intraductal papillary-mucinous neoplasms of the pancreas: clinical, radiological, and pathological analysis of 123 cases

OBJECTIVE

We aimed to investigate preoperative findings that are useful to distinguish intraductal papillary-mucinous neoplasm (IPMN) subtypes.

METHODS

One hundred twenty-three patients who underwent pancreatectomy for IPMN were analyzed clinicopathologically and radiologically. Invasive IPM carcinomas (IPMCs) were subdivided into early-stage nonaggressive (minimally invasive IPMC [MI-IPMC]) and more advanced and aggressive (invasive carcinoma originating in IPMC [IC-IPMC]) subtypes according to our recently proposed pathological criteria.

RESULTS

The lesions consisted of 27 IPMNs with low-grade dysplasia, 14 IPMNs with moderate dysplasia, 21 IPMNs with high-grade dysplasia, 30 MI-IPMCs, and 31 IC-IPMCs. Multidetector-row computed tomography detected a component of invasive carcinoma in IC-IPMC with 86% sensitivity and 100% specificity. In patients with IPMNs other than IC-IPMC, multivariate analysis demonstrated 3 significant predictive factors of malignancy: IPMN size (>40 mm), IPMN duct type (main pancreatic duct or mixed type), and the presence of a mural nodule or thick septum. The diagnostic score obtained using these 3 factors showed a strong correlation with the presence of malignancy.

CONCLUSIONS

For preoperative evaluation of patients with IPMN, it is recommended to rule out IC-IPMC using multidetector-row computed tomography and then to categorize IPMN other than IC-IPMC according to malignant potential based on the diagnostic score.

[Importance of endoscopy and endosonography for chronic pancreatitis and benign pancreas tumors]

Endoscopic retrograde pancreatography (ERP) and endoscopic ultrasound (EUS) are superior to cross-sectional imaging procedures for detection of low-grade pancreatitis, but detection of duct alterations is more reliable by middle and high-grade chronic pancreatitis than by low-grade. In addition to assessment of alterations in the pancreatic duct, EUS also allows detection of parenchymatous alterations. Because of the risk of post-ERP pancreatitis, ERP has been mostly eliminated from diagnostic procedures. In contrast, endoscopic retrograde cholangiopancreatography (ERCP) allows an unrivalled access to interventional treatment of inflammatory alterations of the biliopancreatic duct system, by retrograde, non-penetrable papillae even in the rendezvous procedure with EUS-assisted probing of the Ductus Wirsungianus. Despite the technical success of endoscopic procedures, surgical duct decompression has proven to be superior for relief from pancreatitic pain. Biliary drainage is also more likely to be successful on a permanent basis using surgical procedures than by repeat multi-stenting, at least by calcifying pancreatitis. Peroral transgastral transmural therapy of postpancreatitic necroses opens up further options over surgical removal of necroses.

Pancreatic intraductal papillary mucinous neoplasms: role of CT in predicting pathologic subtypes

OBJECTIVE

The objective of our study was to evaluate whether CT can be used to predict the pathologic subtypes of pancreatic intraductal papillary mucinous neoplasms (IPMNs).

MATERIALS AND METHODS

Three radiologists, blinded to the pathologic IPMN subtype, retrospectively and independently reviewed the preoperative CT scans of 38 patients with surgically resected pancreatic IPMN: 11 intraductal papillary mucinous adenomas, 11 intraductal papillary mucinous carcinomas, and 16 intraductal papillary mucinous carcinomas with invasion. The patients, 16 women and 22 men, ranged in age from 38 to 80 years (mean age, 64.3 years). CT findings were correlated with each pathologic subtype using the chi-square (two-sided) test and analysis of variance. Interobserver agreement of the CT diagnosis of pathologic subtype and agreement between the CT diagnosis and pathologic subtype were also studied (kappa statistic).

RESULTS

Predominant main pancreatic duct (MPD) involvement (p = 0.04) and a wide (> 1 cm) connection of a side-branch lesion with the MPD (p = 0.03) correlated with intraductal papillary mucinous carcinoma with invasion. Tumor size, MPD diameter, number of tumors per patient, number of pseudoseptations per tumor, common bile duct dilatation, enlarged lymph nodes, intraductal calcifications, papillary bulging, and presence and size of a solid mass yielded no statistically significant relationship with pathologic subtype. Both interobserver agreement of CT diagnosis (range, 0.004-0.359) and agreement between CT diagnosis and pathologic subtype (range, 0.046-0.317) ranged from slight to fair.

CONCLUSION

Prediction of the pathologic subtypes of pancreatic IPMNs by CT is limited. Predominant MPD involvement and a wide connection of a side-branch lesion with the MPD are the only CT findings that can be used to predict the pathologic subtype of pancreatic IPMN.

Correlation between CT patterns and pathological classification of intraductal papillary mucinous neoplasm

OBJECTIVE

To examine CT patterns of intraductal papillary mucinous neoplasm (IPMN), analyze their correlation with pathologic classification, and discuss the value of CT in the diagnosis and differential diagnosis of IPMN.

METHODS

CT patterns of 39 IPMN patients, whose clinical data were complete and whose diagnosis was confirmed by surgery and pathology, were classified into three types: (1) simple main pancreatic duct (MPD) dilation type, (2) MPD dilation with pancreatic cystic lesion type, and (3) simple pancreatic cystic lesion type. Correlations between the three CT types and Takada pathologic classification (MPD type, furcation type and mixture type) were analyzed. The 39 IPMN cases were pathologically classified as the benign group and the malignant/borderline group. CT characteristics including the presence or absence of mural nodules, intrafocal partitions, focal size and the degree of MPD and common bile duct (CBD) dilation were analyzed statistically.

RESULTS

A correlation was found between the CT simple MPD dilation type and the pathological MPD type, between the MPD dilation with pancreatic cystic lesion type and the furcation and mixture types, and between the simple cystic lesion type and the furcation type (p<0.001). The benign rate was 92% in patients without intrafocal mural nodules, and 42% in patients with intrafocal mural nodules. The difference between the two groups was statistically significant (p=0.003). The presence or absence of intrafocal partitions was not correlated with benignancy or malignancy (p=0.793). The maximum diameter of malignant/borderline lesions was bigger than that of benign ones (p=0.016). There was no significant difference in MPD and CBD diameters between the benign and malignant/borderline groups. Regardless of pathological classification, the MPD diameter was larger than the CBD diameter in all cases (p=0.02).

CONCLUSION

The three CT types of IPMN well correlated with the pathologic classification, which is helpful for analyzing CT manifestations and improving the accuracy of diagnosis. MPD dilation is usually larger than CBD dilation in IPMN patients, which is also helpful in the diagnosis and differential diagnosis of IPMN in the context of other related findings.

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.

Update in imaging of cystic pancreatic masses for gastroenterologists

Cystic pancreatic masses are increasingly recognized as a direct consequence of widespread imaging. Once detected, there is controversy as to further management. This review briefly describes the radiologic appearance of these lesions on computed tomography or magnetic resonance imaging. Recommendations for management based on the imaging findings are discussed.

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 suspected pancreatic cystic neoplasms based on cyst size

BACKGROUND

Evaluation and management of cystic pancreatic neoplasms remain problematic. International consensus guidelines have advised resection for lesions greater than 3 cm.

METHODS

We reviewed our prospective pancreatic cystic neoplasm database for outcomes based on a cyst size of 3 cm.

RESULTS

Five hundred patients have been managed from 1999 to 2006. There were 349 patients (70%) with cysts less than or equal to 3 cm: 293 (84%) were not operated, including 243 nonmucinous cysts: 2 failed observation (0.8%, mean follow-up of 24 months). Fifty-six patients with cysts less than or equal to 3 cm were initially operated (16%), including 23 asymptomatic patients. Histopathology showed intraductal papillary mucinous neoplasm (IPMN) in 20, mucinous cystic neoplasm (MCN) in 18, and serous cystadenoma in 5. Twelve had carcinoma (21%). A total of 151 patients (30%) had cysts greater than cm: 87 (50%) were not operated, including 68 that were nonmucinous: 2 failed observation (2.9%, mean follow-up of 47 months). Sixty-four patients with cysts greater than 3 cm (42%) were initially operated, and final pathology showed MCN in 27, serous cystadenoma in 11, IPMN in 7, and pseudocyst in 7. Twelve had carcinoma (19%). Patients with cysts less than or equal to 3 cm were less likely to be operated (16 vs 42%; P < .001), less often symptomatic (39 vs 50%; P = .017), while older (mean age, 65 vs 61 years; P = .03). Had patients been managed by size alone, up to 20% would have received inappropriate treatment. Management based on aspiration was significantly better in predicting mucinous neoplasms compared with size (75% vs 57%; P < .001), including asymptomatic patients less than or equal to 3 cm (78% vs 65%; P = .003).

CONCLUSION

Size of pancreatic cystic lesions alone is not a reasonable basis for determining management.

Intraductal papillary mucinous neoplasms of the pancreas: indication, extent, and results of surgery

In intraductal and papillary mucinous neoplasm (IPMN) of the pancreas, the aims of surgery differ according to the presence of malignancy. For malignant IPMN and especially for invasive malignancy, radical resection is essential, but entails a substantial operative risk and long-term pancreatic insufficiency. For benign IPMN, in theory, the operative risk and the loss of pancreatic function should be minimal. Thus, surgery for malignant and benign IPMN differs in patient selection, surgical technique, and accepted risk of long-term functional disorders. This article details the indications, surgical techniques, and results of surgery in IPMN.

Intraductal papillary mucinous neoplasm of the pancreas: assessment of the likelihood of invasiveness with multisection CT

PURPOSE

To evaluate the capabilities of multisection computed tomography (CT) in determining the likelihood of invasiveness of intraductal papillary mucinous neoplasm (IPMN).

MATERIALS AND METHODS

The institutional review board approved this research and waived informed consent from the patients. Two radiologists blinded to the pathologic assessment of malignancy or parenchymal invasion of IPMN retrospectively evaluated CT images of 61 consecutive surgically resected tumors (26 adenomas, 15 noninvasive carcinomas, and 20 invasive carcinomas) in patients who underwent multiphase contrast material-enhanced CT with 0.5- or 1-mm collimation. The findings were statistically analyzed by using univariate and multivariate analyses, with the optimal cutoff levels of each continuous parameter determined by generating receiver operating characteristic curves.

RESULTS

The following findings showed significant differences among the three groups: maximum diameter of the main pancreatic duct (MPD), size (length of major axis) of the largest mural nodule in the MPD or in any associated cystic lesion, abnormal attenuating area in the surrounding parenchyma, calcification in the lesion, protrusion of the MPD into the ampulla of Vater, and bile duct dilatation. An MPD diameter of 6 mm or larger, a mural nodule of 3 mm or larger, and an abnormal attenuating area were independently predictive of malignancy. A mural nodule of 6.3 mm or larger in the MPD and an abnormal attenuating area were independently predictive of parenchymal invasion. According to these criteria, the sensitivity, specificity, and accuracy for identifying malignancy were 83%, 81%, and 82% and for identifying parenchymal invasion were 90%, 88%, and 89%, respectively.

CONCLUSION

Multisection CT is useful for distinguishing among adenoma, noninvasive carcinoma, and invasive carcinoma in patients with IPMN.

Incidental cystic neoplasms of pancreas: what is the optimal interval of imaging surveillance?

BACKGROUND

The optimal interval of imaging studies for surveillance of incidental pancreatic cystic neoplasms is not known.

OBJECTIVE

A retrospective analysis of longitudinal medical records of patients with pancreatic cystic neoplasms was performed to examine the natural history of incidentally detected cystic pancreatic neoplasms with respect to the development of significant growth and to identify predictors of such growth.

RESULTS

After excluding patients with small (<10 mm) cysts (N = 144) and inadequate clinical follow-up of less than 6 months (N = 79) and those with a clinical diagnosis of pancreatic pseudocysts, serous cystadenoma, main duct intraductal papillary mucinous neoplasm (N = 29), and neuroendocrine tumor (N = 3), in total, 166 cysts in 150 patients were available for analysis. The working diagnoses on these cysts (based on clinical, radiological features, aspiration cytology, cyst fluid analysis, and surgical pathology data when available) were mucinous cystic neoplasm in 117 and branch-type intraductal papillary mucinous neoplasm in 49. The mean standard error (SE) initial size of these cysts was 2 (0.1) cm. Over a median period of follow-up of 32 (IQR [inter-quartile range] 19-48) months, 89% of all the cysts did not show significant growth during the follow-up. In a multivariate Cox proportional hazards model, the initial size of the cystic lesion was an independent predictor of significant growth during follow-up (relative risk 1.28, 95% confidence interval [CI] 1.08-1.61, P= 0.01); the only other significant variable was the presence of intracystic or mural nodule (relative risk 38.6, 95% CI 2.3-654, P= 0.01).

CONCLUSION

Most incidentally detected cystic neoplasms of the pancreas did not have significant growth during follow-up. Such growth is unlikely to occur before 2 yr of the baseline evaluation, and we suggest that the optimal imaging interval during follow-up of these patients should be at 2 yr from the baseline evaluation, particularly in cystic lesions 3.0 cm or less in size and without intracystic or mural nodules.

Intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasm (IPMN) is characterized by enhanced mucus secretion. It is a benign or low-grade neoplasm associated with a dilated main pancreatic duct, patulous ampullary orifice, and abundant mucus secretion. Foci of aggressive cancer may arise and become invasive. Surgery is the only treatment that can cure IPMN, but the extent of pancreatic resection and the intraoperative margins remain areas of controversy. The risks of total pancreatectomy must be weighed against the risk for developing cancer in the residual pancreas. Risks must be factored against the natural course of the disease and the likelihood of malignancy developing over the life expectancy.

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 neoplasms of the pancreas: clinicopathologic characteristics and long-term follow-up after resection

BACKGROUND

Resection is recommended for main duct intraductal papillary mucinous neoplasms (IPMNs) of the pancreas because of the high risk of malignancy, but the indications for resection of branch duct and mixed-type IPMNs remain controversial. Our objective was to determine the appropriate management of IPMNs based on clinicopathologic characteristics and survival data obtained after resection.

METHODS

A total of 72 consecutive IPMN patients who underwent resection between January 1984 and June 2006 were reviewed. The lesions were classified as main duct, branch duct, or mixed-type IPMNs and histologically graded as noninvasive (adenoma, borderline neoplasm, carcinoma in situ) or invasive.

RESULTS

Main duct IPMNs (n=15) were associated with a significantly worse prognosis than other subtypes. For branch duct (n=49) and mixed-type IPMNs (n=8), the diameter of the cystic lesions was an independent predictor of malignancy by multivariate analysis. However, four patients with cysts<30 mm in diameter and no mural nodules had a malignancy. No patient with noninvasive IPMN died of this disease, showing excellent survival, whereas the 5-year survival rate of patients with invasive IPMNs was only 57.6% and was significantly worse than that of patients with noninvasive IPMNs (p=0.0002).

CONCLUSIONS

Resection of all main duct IPMNs seems to be reasonable. Invasive IPMNs were associated with significantly worse survival than noninvasive IPMNs. Although the diameter of cystic lesions was a predictor of malignancy for branch duct and mixed-type IPMNs, precise preoperative identification of malignancy was difficult. Therefore, these lesions should be managed by aggressive resection before invasion occurs to improve survival.

Cystic lesions of the pancreas. A diagnostic and management dilemma

BACKGROUND/AIMS

Due to enhanced imaging modalities, pancreatic cysts are being increasingly detected, often as an incidental finding. They comprise a wide range of differing underlying pathologies from completely benign through premalignant to frankly malignant. The exact diagnostic and management pathway of these cysts remains problematic and this review attempts to provide an overview of the pathology underlying pancreatic cystic lesions and suggests appropriate methods of management.

METHODS

A search was undertaken with a Pubmed database to identify all English articles using the keywords 'pancreatic cysts', 'serous cystadenoma', 'intraductal papillary mucinous tumour', 'pseudocysts', 'mucinous cystic neoplasm' and 'solid pseudopapillary tumour'.

RESULTS

The mainstay of assessment of pancreatic cysts is cross-sectional imaging incorporating CT and MRI. Fine-needle aspiration (FNA) (often with endoscopic ultrasound) may provide valuable additional information but can lack sensitivity. Symptomatic cysts, increasing age and multilocular cysts (with a solid component and thick walls) are predictors of malignancy. A raised cyst aspirate CEA, CA 19-9 and mucin content (including abnormal cytology), if present, can accurately distinguish premalignant and malignant cysts from benign ones.

CONCLUSION

In summary, all patients with pancreatic cystic lesions, whether asymptomatic or symptomatic, must be thoroughly investigated to ascertain the underlying nature of the cyst. Small asymptomatic cysts (<3 cm) with no suspicious features on imaging or FNA may be safely followed up. Follow-up should continue for at least 4 years, with a repeat FNA if needed. An algorithm for the management of pancreatic cystic tumours is also suggested. and IAP.

Cytological and cyst fluid analysis of small (< or =3 cm) branch duct intraductal papillary mucinous neoplasms adds value to patient management decisions

BACKGROUND/AIM

Management of patients with small (1-3 cm) branch duct intraductal papillary mucinous neoplasms (IPMN) is a challenge. Symptoms, dilated duct, mural nodule or positive cytology have been proposed as parameters for resection. The aim of our study was to compare this proposed algorithm to one that incorporates cytology with less than malignant epithelial cells and cyst fluid carcinoembryonic antigen (CEA).

METHODS

A retrospective study was conducted.

RESULTS

There were 14 nonmalignant and 6 malignant cysts with 3 invasive IPMN. None were associated with a dilated duct and none had positive cytology. Only a mural nodule was significant by univariate analysis for the detection of malignancy (p = 0.01) and invasion (p = 0.009). The detection of atypical epithelial cells or a cyst fluid CEA of >2,500 ng/ml was more accurate for the detection of malignancy than using the recommended algorithm.

CONCLUSIONS

The presence of a mural nodule in a small branch duct IPMN is a predictor of malignancy and invasion by univariate analysis. Recognition of an atypical epithelial cell component in contrast to positive cytology or a cyst fluid CEA of >2,500 ng/ml is more accurate than the recommended algorithm and adds value to the preoperative assessment of clinically diagnosed small branch duct IPMN. and IAP.

Management of intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are being diagnosed with increasing frequency, probably due to the widespread use of cross-sectional imaging. The natural history of these tumors is still largely unknown. Several studies have shown topographical as well as biological differences between main duct and branch duct IPMNs. In the past few years, diagnostic work-up and, in particular, management of these tumors have evolved significantly. Data support the need for resection of main duct IPMNs and the possibility of nonoperative management in selected cases of branch duct tumors. In this systematic review, we analyze the most recent publications related to IPMNs, with particular emphasis on problems related to managing this challenging disease.

Intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are now a well-recognized category of slowly growing tumors with a remarkably better prognosis, even when malignant, than pancreatic ductal adenocarcinoma. Their clinical and pathohistologic features have been increasingly attracting the attention of clinicians since their first description 25 years ago. Despite its burgeoning volume recently, accumulated literature devoted to IPMN still provides a low level of evidence with regard to diagnosis, treatment, and prognosis. Therefore, we performed a Medline-based systematic review of the literature aimed at clearly defining the clinicopathologic characteristics of pancreatic IPMN and determining the best currently available evidence-based principles of diagnosis and management of patients with this disease.

Surgical management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is characterized by papillary growths within the pancreatic ductal system that are at risk for undergoing malignant transformation. Main duct IPMN carries a significant risk of malignancy, and operation is recommended regardless of the presence of symptoms. The risk of malignancy is much lower for side branch IPMN, and current evidence suggests that, in the absence of symptoms, mural nodules, positive cytology, or cyst size less than 3 cm, observation is warranted. When operation is indicated, targeted pancreatic resection with frozen-section analysis of margins is recommended. Pancreatoduodenectomy or distal pacreatectomy is appropriate for the majority. Only in about 10% of patients is the disease so diffuse at presentation that total pancreatectomy is necessary. Survival following pancreatic resection for noninvasive IPMN is excellent. The risk of recurrence following pancreatic resection for invasive IPMN is significant. Surveillance is warranted both for patients subjected to pancreatic resection and for those under observation with side branch IPMN. Much is yet to be learned regarding this neoplasm, and surgical management remains in evolution.

Cystic neoplasia of the pancreas: pathology and biology

In contrast with solid tumors, most of which are invasive ductal adenocarcinoma with dismal prognosis, cystic lesions of the pancreas are often either benign or low-grade indolent neoplasia. Those that are mucinous, namely, intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs), constitute the most important category, not only because they are the most common, but more importantly because they have well-established malignant potential, representing an adenomacarcinoma sequence. While many are innocuous adenomas--in particular, those that are small and less complex, and in the case of IPMN, those that are branch-duct type are more commonly benign, some harbor or progress into in situ or invasive carcinomas. For this reason, pancreatic cysts with mucinous differentiation ought to be evaluated carefully, preferably by experts familiar with subtle evidences of malignancy in these tumors. In the past few years, the definition of IPMNs and MCNs has become more refined. The presence of ovarian-type stroma has now almost become a requirement for the diagnosis of MCN, and when defined as such, MCN is seen almost exclusively in women of perimenopausal age group as thick-walled multilocular cystic mass in the tail of the pancreas in contrast with IPMN which afflicts an elder population, both genders in almost equal numbers, and occur predominantly in the head of the organ. While mucinous lesions have well-established pre-malignant properties, most of the entities that fall into the nonmucinous true cyst category such as serous tumors, lymphoepithelial cysts, congenital cysts, and squamoid cyst of ducts have virtually no malignant potential. In contrast, the rare cystic tumors that occur as a result of degenerative/necrotic changes in otherwise solid neoplasia such as the rare cystic ductal adenocarcinomas, cystic endocrine neoplasia, and most importantly, solid-pseudopapillary tumor (SPT) in which cystic change is so common that it used to be incorporated into its name ("solid-cystic," "papillary-cystic") are malignant neoplasia, albeit variable degrees of aggressiveness. SPT holds a distinctive place among pancreatic neoplasia because of its highly peculiar characteristics, undetermined cell lineage, occurrence almost exclusively in young females, association with beta-catenin pathway, and also by being a very low-grade curable malignancy. In conclusion, cystic lesions in the pancreas constitute a biologically and pathologically diverse category most (but not all) of which are either benign or treatable diseases; however, a substantial subset, especially mucinous ones, has malignant potential that requires careful analysis.

Predictors of malignant potential of cystic lesions of the pancreas

BACKGROUND

Cystic lesions of the pancreas (CLP) are a diagnostic dilemma, the correct characterisation of which determines surgical management.

METHODS

From 1995 to 2005, radiology and pathology records were reviewed for the presence of CLP. CLP were divided into three groups; Group 1: Benign, Group 2: Pre-malignant, and Group 3: Malignant.

RESULTS

Seventy-nine of 121 patients were included [Group 1: n=46, Group 2: n=10, Group 3: n=23], with a median age at diagnosis of 68 (31-92) years. The median follow-up period was 24 (14-84) months. On univariate analysis, female gender (p=0.04), jaundice (p<0.01), raised serum ALT concentration (p=0.03), cyst size (> or = 2.5 cm) (p<0.01), and biliary duct dilatation (p<0.01) were associated with malignant potential. Benign cysts were more likely to present incidentally (p<0.01). On multi-variate analysis, cyst size (> or =2.5 cm) was an independent predictor of malignant potential. Sub-group analysis revealed that cysts <2.5 cm in the head of the pancreas with evidence of biliary obstruction (either abnormal liver function; raised ALT [p=0.01], ALP [p=0.01], total bilirubin [p=0.02], and/or biliary duct dilatation [p<0.01]) were associated with malignant potential.

CONCLUSION

Cyst size > or =2.5 cm on computer tomography imaging was an independent predictor of pre-malignant and malignant pancreatic cysts. Cyst size and the presence of biliary obstruction predict potentially malignant cysts of the head of the pancreas, which require surgical management.

Benign pancreatic tumors

The goal of this article is to describe the different types of benign pancreatic neoplasms, methods to distinguish between them, and treatment options. Pancreatic adenocarcinoma is associated with specific neoplastic lesions that are similar in radiographic appearance to some benign lesions. The correct differentiation of these malignant and premalignant lesions from their benign counterpart is paramount to their proper management.

Pancreatic head resection with segmental duodenectomy: safety and long-term results

OBJECTIVE

To evaluate the usefulness and long-term results with pancreatic head resection with segmental duodenectomy (PHRSD; Nakao's technique) in patients with branch-duct type intraductal papillary mucinous neoplasms (IPMNs). A prospective study from Nagoya (Japan) and Barcelona (Spain).

SUMMARY BACKGROUND DATA

Surgery should be the first choice of treatment of IPMNs. An aggressive surgery (eg, pancreatoduodenectomy) should be questioned in patients with an indolent disease or with noninvasive tumors. Recently, organ-preserving pancreatic resections for benign and noninvasive IPMN located in the head of the pancreas have been described. We have PHRSD in which the pancreatic head can be completely resected and the major portion of the duodenum can be preserved by this procedure. There have been only 4 reports concerning PHRSD with <8 patients (each one) in the English literature.

METHODS

Thirty-five patients underwent PHRSD (20 men, 15 women), mean age 65.1 +/- 9.0 (range, 55-75). Mean maximal diameter of the cystic lesion was 26.4 +/- 5.3 mm (range, 20-33 mm) and mean diameter of the main pancreatic duct was 3.3 +/- 0.5 mm (range, 3.0-4.0 mm). Alimentary tract reconstruction was performed in 20 patients by pancreatogastrostomy, duodenoduodenostomy, and choledochoduodenostomy (type A) and 15 patients by pancreaticojejunostomy, duodenoduodenostomy and choledochojejunostomy (Roux-en-Y; type B). Surgical parameters, postoperative complications, endocrine function, exocrine function, and long-term outcomes were evaluated. To compare the perioperative factors, a matched-pairs analysis between PHRSD patients and patients with pylorus preserving pancreaticoduodenectomy (PPPD) was performed. In the latter group were included 32 patients with branch-duct type of IPMN operated during the same time period that patients with PHRSD. The mean follow-up period was 48.8 months.

RESULTS

Mean operative time after PHRSD was 365 +/- 50 and mean surgical blood loss was 615 +/- 251 mL. There was no mortality. Pancreatic fistula occurred in 10% and 13% with types (alimentary tract reconstruction) A and B, respectively. Noninvasive IPMN was found in 31 patients and invasive IPMN in 4 patients (11.4%). In the matched-pairs analysis between PHRSD and PPPD, the 2 procedures were comparable in regard to operation time and intraoperative blood loss. The overall incidence of pancreatic fistula was higher after PPPD than after PHRSD; the difference was not statistically significant. When fistulas occurred after PHRSD they were grade A (biochemical). In contrast, pancreatic fistulas after PPPD were grade A in 78% of cases and grade B in 22% (clinically relevant fistula). The incidence of delayed gastric emptying was significantly higher in the PPPD group compared with the PHRSD group (P < 0.01). Endocrine pancreatic function, measured by fasting blood glucose levels and HbA1, levels was unchanged in 94.28% of patients, in the PHRSD group, and in 87.87% in the PPPD group. Body weight was unchanged in 80% after PHRSD and in 59% after PPPD. Postoperative enzyme substitution was needed in 20% of patients after PHRSD and in 40% patients after PPPD. The 5-year survival rate was 100% in patients with benign IPMN and 42% in patients with invasive IPMN.

CONCLUSION

PHRSD is a safe and reasonable technique appropriate for selected patients with branch-duct IPMN. The major advantages of PHRSD are promising long-term results in terms of pancreatic function (exocrine and endocrine) with important consequences in elderly patients. Long-term outcome was satisfactory without tumor recurrence in noninvasive carcinoma. PHRSD should therefore be considered as an adequate operation as an organ-preserving pancreatic resection for branch-duct type of IPMN located at the head of the pancreas.