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

Intraductal papillary mucinous neoplasm--when to resect?

Based on the experience to date with IPMNs, the approach to patients remains relatively complex. A meticulous and careful approach to diagnosis, oncologic risk assessment, operative planning, and surveillance is needed to adequately address these lesions. Indications for resection in patients with IPMN are (1) cancer, (2) cancer prevention in patients at high risk for malignant transformation, and (3) management of symptoms. Differentiating patients who have IPMNs by type is an important initial step in providing optimal care (Fig. 6). In patients with MPD involvement (main- and mixed-type IPMN), the risk of malignancy at resection is too high to justify nonoperative management unless comorbidity or patient preference precludes operation. Until better preoperative biomarkers of malignancy in main duct-involved IPMNs are available, it is our recommendation that all patients who are fit should undergo resection of the entire involved segment with appropriate adjustment and extension based on intraoperative pathology. Total pancreatectomy may be indicated for diffuse main duct involvement. In the more difficult and debated cohort (i.e., patients with side branch disease only), a more strategic approach to whether to resect is appropriate. Patients with malignant cytopathology, concerning radiologic features (i.e., mural nodules, associated mass), or symptoms attributable to IPMNs should be offered resection. Importantly, specific symptoms have variable importance in terms of oncologic risk and are worth characterizing in individual patients. Size alone should not be the determining oncologic factor for resection, although we acknowledge that the literature is unclear in this regard. Size of IPMNs (or any other cystic lesion) may be a nononcologic indication to resect for symptom control and when size or anticipated growth may complicate the ability to safely extirpate the lesion. Other factors that should be considered in determining whether to resect are number of lesions, need for prolonged surveillance, inability to adequately perform noninvasive surveillance (e.g., contraindication to MRI), difficulty in surveillance (extensive/diffuse multifocal disease), and patient tolerance of risk. The decision to resect in patients undergoing primary surveillance or secondary surveillance for IPMN should be similar to the indications for primary resection noted previously. The optimal surveillance regimen, however, is unknown. The optimal surveillance regimen depends on the timing and incidence of "recurrence" and "new metachronous IPMIN development," which are not fully understood, partly because of suboptimal preoperative imaging in patients with IPMNs. To solve this mystery, surgeons and pancreatologists should be encouraged to obtain optimal and timely imaging studies before taking patients to the operating room. Patients should be followed at least annually with history and physical and optimal cross-sectional imaging. Endoscopy and cytopathologic assessment should be considered at least biannually and more often when indicated by patient symptoms or concerning radiographic features. The surveillance interval should be decreased and extent of testing increased based on patients with higher oncologic risk stratification. Although resection in patients undergoing surveillance currently follows the same algorithm as patients undergoing primary resection, assessment of the main pancreatic duct in patients undergoing secondary surveillance after segmental pancreatectomy (particularly pancreaticoduodenectomy) is complicated. Although new data continue to clarify how and when to approach IPMNs with segmental or total pancreatic resection, many questions remain unanswered. Continued efforts to uncover a more accurate natural history and behavior for IPMN continue to fill the gaps in our current understanding and practice. In the meantime, it is critical to educate and frequently restratify oncologic risk in patients based on optimal and timely data (history and physical and radiographic, endoscopic, and cytopathologic results) and rigorous follow-up to guide patients in reaching a decision of whether and when to undergo IPMN resection.

Dynamic computed tomography findings of malignant intraductal papillary mucinous tumor compared with invasive ductal adenocarcinoma

PURPOSE

We evaluated the effectiveness of dynamic computed tomography (CT) imaging in differentiating malignant intraductal papillary mucinous tumor (IPMT) with a large mural nodule from invasive ductal adenocarcinoma (IDAC).

MATERIALS AND METHODS

Dynamic CT was done in six IPMT and nine IDAC cases. In the IPMT cases, we made a histological map of the tumor. A region of interest (ROI) was established in the mural nodule of the IPMT, in the IDAC, and in the noncancerous portion of the pancreas. The change of density was analyzed statistically during preenhancement and the early and late phases. These results were compared between the IPMT and IDAC cases.

RESULTS

Histologically, most of the mural nodule was papillary adenocarcinoma. In the IPMT cases, the postenhancement density of the mural nodule was significantly higher during the early phase than during the late phase. In IDAC cases, the postenhancement density was significantly higher in the late phase than in the early phase. In the early phase, tumor-pancreas density was significantly higher in the IPMT than in the IDAC. In the late phase, tumor-pancreas density was significantly higher in the IDAC than in the IPMT.

CONCLUSION

Dynamic CT is useful for differentiating malignant IPMT with a large mural nodule from IDAC.

Intraductal papillary mucinous neoplasms: predictors of malignant and invasive pathology

OBJECTIVE

Determine whether size and other preoperative parameters predict malignant or invasive intraductal papillary mucinous neoplasia (IPMN).

SUMMARY BACKGROUND DATA

From 1991 to 2006, 150 patients underwent 156 operations for IPMN.

METHODS

Prospectively collected, retrospective review of a single academic institution's experience. All preoperative parameters including a detailed radiologic-based classification of IPMN type, location, distribution, size, number, cytology, and mural nodularity were correlated with IPMN pathology.

RESULTS

Malignant IPMN was present in 32% of cases, whereas 19% of cases were invasive. IPMN type and main pancreatic duct diameter were significant predictors of malignant IPMN (P<0.001). Side-branch lesion number was negatively associated with invasive IPMN (P=0.03). Side-branch size, location, and distribution did not predict IPMN pathology. The presence of mural nodules was associated with malignant and invasive IPMN (P<0.001; P<0.02). Atypical cytopathology was significantly associated with malignant and invasive IPMN (P<0.001; P<0.001). Multivariate analysis demonstrated mural nodularity and atypical cytopathology were predictive of malignancy and/or invasion in branch-type IPMN.

CONCLUSIONS

To lower the rate of invasive pathology, surgery should be recommended for fit patients with main-duct IPMN and for branch-duct IPMN with mural nodularity or positive cytology irrespective of location, distribution, or size.

Collateral branches IPMTs: secretin-enhanced MRCP

Recently, the fantastic evolution of imaging modalities (especially MR, MDCT, EUS) has raised many issues regarding the correct classification of smaller and smaller lesions, their preoperative evaluations, and indications of most appropriate treatment. However, it is still debated which technique should be employed for the diagnosis and the follow-up of intraductal papillary mucinous tumours (IPMTs). Despite the superb spatial resolution of MDCT, nowadays most of the authors agree on considering MR with magnetic resonance cholangiopancreatography (MRCP) the imaging modality of choice in studying IPMTs. In particular, MRCP is rapid, non-invasive, and accurate in detecting, localizing, and correctly classifying IPMT. The diagnostic performance of MRCP is even improved after the introduction of secretin stimulation. In fact, dynamic MRCP studies after secretin administration, besides facilitating the depiction of the structural characteristics of the lesions, make easier the detection of the communicating duct of branch duct IPMTs with the main pancreatic duct, especially if the newest high resolution 3D heavily T2-weighted sequences are utilized. Secretin stimulation is also useful in the demonstration of early changes of associated chronic pancreatitis. Consequently, we believe that secretin-enhanced MRCP is the most suitable imaging modality in the diagnosis and follow-up of IPMTs of the collateral branches.

Treatment guidelines for branch duct type intraductal papillary mucinous neoplasms of the pancreas: when can we operate or observe?

BACKGROUND

The objectives of this study were to investigate the clinicopathological features of branch intraductal papillary mucinous neoplasm (IPMN) and to determine safe criteria for its observation. Most clinicians agree that surgical resection is required to treat main duct-type IPMN because of its high malignancy rate. However, no definite treatment guideline (with respect to surgery or observation) has been issued on the management of branch duct type IPMN.

METHODS

We retrospectively reviewed the clinicopathological data of 138 patients who underwent operations for IPMN between 1993 and 2006 at five institutes in Korea.

RESULTS

Of 138 patients (mean age, 60.6 years; 87 men, 51 women), 76 underwent pancreatoduodenectomy, 39 distal pancreatectomy, 4 total pancreatectomy, and 20 limited pancreatic resection. There were 112 benign cases: 47 adenoma, 63 borderline cases, and 26 malignant cases, with 9 of these being noninvasive and 17 invasive. By univariate analysis, tumor size and the presence of a mural nodule were identified as meaningful predictors of malignancy. By receiver operating characteristic curve analysis, a tumor size of >2 cm was found to be the most valuable predictor of malignancy. When cases were classified according to tumor size and the presence of a mural nodule, the malignancy rate for a tumor </=2 cm without a mural nodule was 9.2%, for a tumor of </=2 cm plus a mural nodule was 25%, and for other conditions such as tumor >2 cm, >25%.

CONCLUSIONS

Many branch duct IPMNs are malignant. Surgical treatment is recommended, except in cases that are strongly suspected to be benign or cases that present a high operative risk. Observation is only recommended in patients with a tumor size of </=2 cm without a mural nodule.

Malignant intraductal papillary mucinous neoplasm of the pancreas: in situ versus invasive carcinoma surgical resectability

PURPOSE

To retrospectively evaluate computed tomographic (CT) findings in patients with in situ and invasive malignant intraductal papillary mucinous neoplasms (IPMNs) of the pancreas and to evaluate the accuracy for surgical resectability, with surgery and pathologic analysis as the reference standards.

MATERIALS AND METHODS

Institutional review board approval was obtained, and the informed consent requirement was waived. Forty-six patients with malignant IPMN proved at pathologic examination of the surgically resected specimen (n = 44) or laparotomy (n = 2) underwent surgery after multidetector CT was performed. CT findings were retrospectively evaluated to determine if a pancreatic malignant IPMN tumor was present; to make this determination, CT criteria were used to differentiate in situ from invasive tumors and signs of unresectability (liver metastasis, vascular CT pattern of encasement, or regional lymph node metastasis). The extent of the vascular CT pattern of encasement was recorded for each patient (no obliteration of the fat plane, obliteration of the fat plane of <50%, or obliteration of the fat plane of > or =50%). Statistical analysis was performed with the chi(2) and Student t tests.

RESULTS

CT revealed a mural nodule in the pancreatic duct wall in 14 patients with in situ carcinoma and one patient with invasive carcinoma (P < .003). CT revealed an infiltrative pancreatic mass in 17 patients with invasive carcinoma and two patients with in situ carcinoma (P < .02). Of the mural nodules, 93% were seen in patients with in situ carcinoma, whereas 90% of infiltrative pancreatic masses were observed in patients with invasive carcinomas. The positive predictive value of CT for determining resectability was 100%, and the overall accuracy of CT for determining resectability and unresectability was 74%. The positive predictive value of CT for determining unresectability was 17%, mainly owing to overestimation of arterial invasion.

CONCLUSION

CT is helpful in the differentiation of in situ and invasive IPMN. Classic vascular invasion criteria lead to the overestimation of surgical tumor unresectability in patients with malignant IPMN.

Proposed new score predicting malignancy of intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

Our objective was to predict malignancy for intraductal papillary mucinous neoplasms of the pancreas (IPMN) before operation.

METHODS

Sixty-four resected patients with IPMN were examined and 17 parameters were investigated for their relation to malignancy by univariate and multivariate analysis.

RESULTS

Multivariate logistic regression analysis showed that IPMN type, the size of main pancreatic duct, and serum carbohydrate antigen 19-9 were significant for malignancy. Size of the main pancreatic duct > or = 6.5 mm and serum carbohydrate antigen 19-9 > or = 35 U/mL scored 3 points, main duct type scored 2 points, and patulous papilla, jaundice, diabetes mellitus, and tumor size > or = 42 mm scored 1 point. When IPMNs with 3 and more than 3 points using the new score were diagnosed as malignant, accuracy was 90.6%.

CONCLUSION

This scoring system for IPMN is feasible to detect malignancy and useful for selecting an appropriate treatment.

Surgical Outcome of Intraductal Papillary Mucinous Neoplasms of the Pancreas

OBJECTIVE

An increasing number of intraductal papillary mucinous neoplasms of the pancreas have been reported in recent years. However, the clinicopathologic features and surgical outcome of this neoplasm are not fully understood because of the limited number of cases. The objective of this study is to clarify the clinicopathologic features of intraductal papillary mucinous neoplasm of the pancreas and evaluate prognostic factors influencing survival.

METHODS

Eighty-two patients with intraductal papillary mucinous neoplasm undergoing surgical resection at the National Cancer Center Hospital East between April 1994 and October 2006 were retrospectively analyzed.

RESULTS

There were 31 patients with adenoma and 51 patients with carcinoma. Carcinomas were subdivided into noninvasive carcinoma (n = 14), minimally invasive carcinoma (n = 6), and invasive carcinoma (n = 31). The postoperative mortality rate was 0%. The 5-year survival rate for patients with intraductal papillary mucinous adenoma, noninvasive carcinoma, minimally invasive carcinoma, and invasive carcinoma was 80%, 78%, 83%, and 24%, respectively. Regardless of the margin status, no patient with adenoma developed recurrent disease. There were significant differences in survival between noninvasive carcinoma and invasive carcinoma (P = .016) and between minimally invasive carcinoma and invasive carcinoma (P = .030). Multivariate analysis confirmed that lymph node metastasis (P = .004) and age (P = .015) were significant prognostic factors after surgical resection of these neoplasms.

CONCLUSIONS

Patients with intraductal papillary mucinous adenoma, noninvasive carcinoma, and minimally invasive carcinoma showed favorable survival. In contrast, invasive intraductal papillary mucinous carcinoma was associated with poor survival regardless of the margin status. Nodal involvement was the strongest predictor of poor survival.

Branch-duct intraductal papillary mucinous neoplasms: observations in 145 patients who underwent resection

BACKGROUND & AIMS

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas arising in branch ducts are thought to be less aggressive than their main-duct counterparts, and guidelines for their conservative management were recently proposed. This study describes the combined experience of 2 tertiary centers with branch-duct IPMNs aiming to validate these recommendations.

METHODS

A review of 145 patients with resected, pathologically confirmed, branch-duct IPMNs between 1990 and 2005 was conducted.

RESULTS

Sixty-six patients (45.5%) had adenoma, 47 (32%) borderline tumors, 16 (11%) carcinoma in situ, and 16 (11%) invasive carcinoma. Median age was similar between benign and malignant subgroups (66 vs 67.5 years, respectively). Jaundice was more frequent in patients with cancer (12.5% vs 1.8%, respectively, P = .022) and abdominal pain in patients with benign tumors (45% vs 25%, respectively, P = .025). Forty percent of tumors were discovered incidentally. Findings associated with malignancy were the presence of a thick wall (P < .001), nodules (P < .001), and tumor diameter >or=30 mm (P < .001). All neoplasms with cancer were larger than 30 mm in size or had nodules or caused symptoms. After a mean follow-up of 45 months, the 5-year disease-specific survival for branch-duct IPMNs with noninvasive neoplasms was 100% and, for invasive cancer, was 63%.

CONCLUSIONS

This large cohort of resected branch-duct IPMNs shows that cancer is present in 22% of cases and validates the recent guidelines that indicate absence of malignancy in tumors <30 mm, without symptoms or mural nodules.

Presentation and management of pancreatic cystic neoplasms

Pancreatic cystic neoplasms are less frequent than other pancreatic tumors, but because of the wide availability and improvement of modern imaging methods, these neoplasms are being recognized with increasing frequency and it is often possible to be differentiated preoperatively not only from other cystic pancreatic disorders but also from one another. Most patients have no symptoms while clinical signs are not really useful in the clinical work up, and when they are present, they never help us to identify the type of pathology. Treatment differs with the diagnosis. Serous cystic neoplasms are uniformly benign and usually do not mandate resection unless this lesion is symptomatic. In contrast, mucinous cystic neoplasms and intraductal papillary mucinous neoplasms have a premalignant or malignant tendency, and therefore should be managed aggressively by pancreatic resection; in the absence of invasive disease, prognosis is excellent after appropriate surgery, but the presence of invasive malignancy signifies a poor prognosis. Solid pseudopapillary neoplasms have nonaggressive behavior and their management is related to the extension of the disease. The purpose of this article is to review the types of pancreatic cystic neoplasms, their diagnosis, indications for surgical treatment, and outcome.

Intraductal papillary mucinous neoplasia

Intraductal papillary mucinous neoplasia is a neoplastic disorder of varying degree and extent that affects the pancreatic ductal epithelium. Clinical presentations may vary from an asymptomatic incidental finding to obstructive jaundice. Harbingers of malignancy include symptoms of jaundice, weight loss, or new-onset diabetes. In the absence of findings that correlate with malignancy, natural history is unknown. Management of these patients is controversial, and should be individualized based on surgical risk.

The clinicopathologic features of intraductal papillary mucinous neoplasms of the pancreas

Since first described in 1982, intraductal papillary mucinous neoplasm (IPMN) has been the preferred term to describe the proliferation of the pancreatic ductal epithelium. It is totally different from pancreatic carcinoma in epidemiology, histology, pathology and prognosis. According to the site of involvement, IPMNs are classified into three categories, i.e. main duct type, branch duct type, and combined type. Most branch duct IPMNs are benign, whereas the other two types are often malignant. A large branch duct IPMN and marked dilation of the main pancreatic duct indicate the presence of adenoma at least. The additional existence of large mural nodules increases the possibility of malignancy in all types. The prognosis is more favorable after complete resection of benign and non-invasive malignant IPMNs. Malignant IPMNs that become more aggressive after parenchymal invasion necessitate adequate lymph node dissection. On the other hand, asymptomatic branch duct IPMNs without mural nodules can be observed without the need for resection for a considerable period of time. Our review addresses available data, current understanding, controversy, and future directions about IPMNs.

Precursor lesions of pancreatic cancer: molecular pathology and clinical implications

BACKGROUND

Pancreatic cancer is a lethal disease, with near uniform 5-year mortality rates. The key to improving survival of pancreatic cancer rests upon early detection of this neoplasm at a resectable, and hence potentially curable, stage.

METHODS

We review the current state of the literature vis-à-vis the three common precursor lesions of pancreatic adenocarcinoma: pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasm, and mucinous cystic neoplasm. We also discuss two clinical scenarios of emerging importance, namely asymptomatic pancreatic cysts ('pancreatic incidentalomas') and the significance of precursor lesions in familial pancreatic cancer kindreds.

RESULTS

Pancreatic intraepithelial neoplasias are the microscopic precursor lesions of pancreatic adenocarcinomas, while intraductal papillary mucinous neoplasms and mucinous cystic neoplasms are macroscopic, cystic precursor lesions. All three noninvasive entities demonstrate a multistep morphologic and genetic progression that culminates in frank invasive adenocarcinoma. Despite these commonalities, each precursor lesion harbors a unique repertoire of clinicopathologic and genetic characteristics that has an impact on natural history and prognosis of these lesions. Due to improvements in radiological techniques, asymptomatic pancreatic cysts are being increasingly discovered in the general population; intraductal papillary mucinous neoplasms and mucinous cystic neoplasms are the most common underlying histology in resected incidentalomas of the pancreas. Pancreatic asymptomatic cysts present an enormous challenge in terms of accurate diagnosis and management stratification. Incorporating molecular signatures of cystic precursor lesions into the diagnostic algorithm will likely become a standard of care for asymptomatic pancreatic cysts. High-risk individuals from familial pancreatic cancer kindreds are another group of individuals where knowledge of precursor lesions has had a therapeutic impact; sensitive imaging technologies have enabled the identification and subsequent resection of pancreatic cancer precursors in these high-risk individuals, preventing the progression to invasive cancer.

CONCLUSIONS

Precursor lesions of pancreatic adenocarcinomas represent a unique opportunity for diagnosis and intervention for a malignancy with near uniform lethality. Further studies on these precursors will enable the development of rational early detection and therapeutic strategies in order to ameliorate pancreatic cancer survival.

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.

Predictive factors of malignant or invasive intraductal papillary-mucinous neoplasms of the pancreas

The aim of this study was to identify useful preoperative diagnostic findings indicative of malignant or invasive intraductal papillary-mucinous neoplasms (IPMN) of the pancreas to determine an optimal operative procedure for IPMN. Sixty-two IPMNs, which consisted of 29 adenomas, 10 borderline tumors, 11 adenocarcinomas in situ, and invasive adenocarcinomas were reviewed from 1990 to 2003. Preoperative predictive factors of malignant or invasive IPMN were analyzed among 10 factors by univariate and multivariate analysis. Diameter of the main pancreatic duct (> or =6 mm) and cytological examination of the pancreatic juice (the presence of malignant cells) were identified as independent predictive factors of malignant IPMN, and only cytological examination of the pancreatic juice (the presence of malignant cells) was identified as an independent predictor of invasive IPMN by multivariate analysis (P < 0.05). There was no recurrent disease in patients with adenoma and adenocarcinoma in situ, whereas recurrences occurred in 6 of 12 patients with invasive IPMN. Patient survival in noninvasive IPMN was significantly (P = 0.018) better than that in invasive IPMN (The overall 5-year survival rates were 87.2% and 49.2%, respectively). These results might be useful for selecting an optimal surgical procedure for IPMN.

[Organ-preserving resection of the pancreaticoduodenal region in the treatment of intraductal papillary mucinous tumors]

INTRODUCTION

The standard surgical procedure for intraductal papillary mucinous neoplasms of the main duct (IPMN-M) or side branch ducts (IPMN-Br) is pancreaticoduodenectomy. IPMN-BR is a more indolent disease with a lower incidence of malignancy.

OBJECTIVE

To evaluate the usefulness of organ-preserving pancreatic resections (OPPR) including duodenum-preserving pancreatic head resection (DPHR) and pancreatic head resection with segmental duodenectomy (PHRSD) in patients with IPMN-BR.

PATIENTS AND METHOD

Surgical outcomes were evaluated in eight IPMN-Br patients: DPHR was performed in 4 patients and PHRSD was performed in 4 patients. In addition, 13 IPMN patients with Whipple resections were included in the analysis.

RESULTS

The incidence of postoperative complications was 38% after Whipple resection, 100% after DPHR and 25% after PHRSD. The mean length of hospital stay was 27 days after DPHR, 22 days after Whipple resection and 16 days after PHRSD. Invasive IPMN was found in 38% of the patients in the Whipple group, and noninvasive IPMN was found in 100% of patients who underwent organ-preserving surgery.

CONCLUSIONS

Pancreaticoduodenectomy remains the treatment of choice in patients with invasive IPMN. PHRSD appears to be a useful procedure for IPMN-Br located in the head of the pancreas.

An analysis of clinico-pathologic features of intraductal papillary mucinous neoplasm of the pancreas

The natural history and clinical manifestation of resected intraductal papillary mucinous neoplasm (IPMN) of the pancreas were elucidated, and based on this, a retrospective pancreatic database was reviewed to identify patients with IPMN who were surgically managed in our department from 1999 to June 2006. Pathologic rereview of each case was performed, and the clinico-pathologic features were examined. Student's T test and χ(2) analysis were used to identify factors associated with malignancy. Fifty-one patients were identified. There were 33 males and 18 females. One patient's pancreas was unresectable, two patients underwent a total pancreatectomy, 42 patients had a pancreatecoduodenectomy and five patients had distal pancreatectomy. Main-duct type carcinoma was identified in 24 patients; branch-duct type in 15 patients, and mixed type in 12 patients. Invasive carcinoma was present in 35 patients. Weight loss and jaundice occurred more commonly in the invasive group. The average serum CA19-9 level was significantly higher in the invasive group (1542μ vs 94.5μ). The average diameter of the pancreatic duct was also wider in the invasive group (8.7 mm vs 4.3 mm). Significant predictors of malignant IPMNs included weight loss, jaundice, a high level of serum CA19-9, a large pancreatic duct and main-duct type carcinoma.

Cystic lesions of the pancreas

Although cystic tumors of the pancreas are relatively rare, they constitute an increasingly important category. Advances in imaging and interventional techniques and the sharp drop in the mortality rate of pancreatic surgery have rendered pancreatic biopsies and resections commonplace specimens. Consequently, in the past two decades, the nature of many cystic tumors in this organ has been better characterized. The names of some existing entities were revised; for example, what was known as papillary-cystic tumor is now regarded as solid-pseudopapillary tumor. New entities, in particular, intraductal papillary mucinous neoplasm and its variants, such as oncocytic and intestinal subtypes were recognized. The importance of clinical and pathologic correlation in the evaluation of these lesions was appreciated, in particular, with regards to the multifocality of these lesions, their association with invasive carcinomas, and thus their 'preinvasive' nature. Consensus criteria for the distinction of these from the ordinary precursors of adenocarcinoma, the pancreatic intraepithelial neoplasia, were established. The definition of mucinous cystic neoplasms was refined; ovarian-like stroma has now become almost a requirement for the diagnosis of mucinous cystic neoplasia, and defined as such, the propensity of these tumors to occur in perimenopausal women became even more striking. The validity and clinical value of classifying the pancreatic cysts of mucinous type as adenoma, borderline, CIS and invasive have been established. Related to this, the importance of thorough sampling in accurate classification of these mucinous lesions was recognized. Greater accessibility of the pancreas afforded by improved invasive as well as noninvasive modalities has also increased the detection of otherwise clinically silent cystic tumors, which has led to the recognition of more innocuous entities such as acinar cell cystadenoma and squamoid cyst of pancreatic ducts. As the significance of the cystic lesions emerged, cystic forms of otherwise typically solid tumors were also better characterized. Thus, significant developments have taken place in the classification and our understanding of pancreatic cystic tumors in the past few years, and experience with these lesions is likely to grow exponentially in the coming years.

Intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND/AIMS

Intraductal papillary mucinous neoplasms (IPMNs) are neoplasms of the pancreatic duct epithelium characterized by intraductal papillary growth and thick mucin secretion. Quantities of mucin fill the main and/or branches of pancreatic ducts and cause ductal dilatation. This review encompasses IPMNs, including symptoms, diagnosis, management, and prognosis.

METHODS

A Pubmed database search was performed. All abstracts were reviewed and all articles in which cases of IPMNs could be identified were further scrutinized. Further references were extracted by cross-referencing.

RESULTS

Only one-third of all patients are symptomatic. According to the site of involvement, IPMNs are classified into three types: main duct type, branch duct type, and combined type. Most branch type IPMNs are benign, while the other two types are frequently malignant. The presence of large mural nodules increases the possibility of malignancy in all types. Presence of a large branch type IPMN and marked dilatation of the main duct indicate the existence of adenoma at least. Synchronous or metachronous malignancies may be developed in various organs. Endoscopic retrograde cholangiopancreatography, endoscopic ultrasonography, and intraductal ultrasonography clearly demonstrate ductal dilatation and mural nodules, while magnetic resonance pancreatography best visualizes the entire outline of IPMNs.

CONCLUSIONS

Prognosis is excellent after complete resection of benign and non-invasive malignant IPMNs. The extent of pancreatic resection and the intraoperative management of resection margins remain controversial. Total pancreatectomy should be reserved for patients with resectable but extensive IPMNs involving the whole pancreas; its benefits, however, must be balanced against operative and postoperative risks. Regular monitoring for disease recurrence is important after surgery.

Intraductal papillary mucinous tumour of the pancreas: differentiation of malignancy and benignancy by CT

AIM

To retrospectively identify signs predictive of malignant intraductal papillary mucinous tumour (IPMT) of the pancreas on computed tomography (CT) images.

MATERIALS AND METHODS

Thirty-four benign and 21 malignant pancreatic IPMTs were evaluated. Preoperative helical CT images in these 55 cases of pathologically proven pancreatic IPMT were reviewed by two radiologists unaware of the histological grading. Tumour morphological types, locations, numbers and sizes of cystic lesions, maximum main pancreatic duct diameters, the presence of septa, mural nodule, wall thickening, and calcification in cysts, communication with the main pancreatic duct, peripancreatic haziness, protrusion of duodenal papilla, pancreatic atrophy, lymphadenopathy and distant metastasis were analysed using univariate and multivariate analysis.

RESULTS

Main duct IPMTs were more likely to be malignant (71%) than branch duct (23%) or combined type IPMTs (28%; p=0.002). Among the branch duct type and combined types, large cystic lesion (p=0.018), the presence of a mural nodule (p=0.018), a thickened wall (p=0.009), and peripancreatic haziness (p=0.039) were found to predict malignancy.

CONCLUSION

CT is helpful in the preoperative differentiation of malignant and benign pancreatic IPMT. The presence of a dilated main pancreatic duct, mural nodules, thickened wall and peripancreatic haziness may be used as independent predictive signs of malignancy.

Pancreatic cancer in patients with pancreatic cystic lesions: a prospective study in 197 patients

BACKGROUND & AIMS

K-ras mutation is frequently detected in pancreatic juice of patients with pancreatic small cystic lesions, as well as those with pancreatic cancer. Those cystic lesions are often found by chance with modern radiologic imaging modalities. In this study, we prospectively examined the prognosis of patients with pancreatic cystic lesions, focusing on pancreatic cancer development.

METHODS

A total of 197 patients with pancreatic cystic lesions, 80 with intraductal papillary mucinous neoplasm (IPMN) and 117 with non-IPMN cysts, were followed up for 3.8 years on average. Blood tests and imaging diagnosis were performed twice a year. The observed incidence of pancreatic cancer was compared with the expected incidence calculated on the basis of age- and gender-matched mortality of pancreatic cancer in the general Japanese population.

RESULTS

Pancreatic cancer developed in 7 patients during the observation period (0.95% per year), infiltrating ductal carcinoma in 5 and intraductal papillary mucinous carcinoma in 2. Three of the ductal cancer cases had pancreatic non-IPMN cyst as preexisting lesion. At least 2 of the carcinomas arose in regions remote from preexisting lesions. The observed incidence of pancreatic cancer was 22.5 times higher (95% confidence interval, 11.0-45.3) than expected mortality from this cancer among general population.

CONCLUSIONS

Patients with pancreatic cystic lesions are at a considerably high risk for pancreatic cancer, with a standardized incidence rate of 22.5. Cancer might develop in regions remote from the preexisting cystic lesion, suggesting diffuse pathologic changes predisposing to malignant transformation in the entire pancreas harboring cystic lesions.

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

GOALS

The aim of this study was to examine and clarify the preoperative markers that are useful for differentiating between benign and malignant lesions of intraductal papillary-mucinous neoplasms (IPMN) of the pancreas, grouped according to morphologic classification.

BACKGROUND

There are various stages of pathology in IPMN, ranging from benign to malignant lesions. Although the determination of appropriate treatment guidelines to deal with IPMN is a critical issue, no such guidelines have been established.

PATIENTS AND METHODS

One hundred twenty cases of IPMN were classified morphologically into either main or branch duct types. We compared the morphologic classification with histopathologic diagnosis using indicators of malignancy detected by imaging such as main duct diameter, the number and diameter of cysts, and the presence or absence of mural nodules. We also examined the usefulness of pancreatic juice cytology and measurement of telomerase activity as indicators of malignancy. Finally, we performed a survival analysis on the basis of morphologic classification to determine prognosis of IPMN.

RESULTS

Whereas a high incidence (64%) of malignant lesions was seen in main duct type IPMN, benign lesions were dominant (80.5%) in branch duct type IPMN. Survival analysis showed that the prognosis was significantly worse in main duct type than in branch duct type IPMN. The lesions were aggravated in all patients with main duct type who did not undergo resection, resulting in death due to progression of the pancreatic lesion. The incidence of mural nodules was a useful indicator in main duct type, whereas main duct diameter and incidence of mural nodules were useful indicators in branch duct type. Although pancreatic juice cytology showed a high accuracy rate with low sensitivity for determining malignancy, measurement of telomerase activity in this juice was very effective for differentiating between benign and malignant lesions.

CONCLUSIONS

The incidence of malignant lesions was extremely high in main duct type IPMN, indicating that surgery is required in all these patients. However, to determine whether surgery is indicated in branch duct type IPMN it is necessary to obtain an appropriate image diagnosis focusing on main duct diameter and mural nodules and also to carry out cytology and measurement of telomerase activity in samples of pancreatic juice.

Intraductal papillary-mucinous neoplasms and mucinous cystic neoplasms of the pancreas differentiated by ovarian-type stroma

BACKGROUND

Intraductal papillary-mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN) of the pancreas have similar clinicopathologic findings. This study was intended to clarify clinicopathologic characteristics in IPMNs and MCNs differentiated by ovarian-type stroma.

METHODS

Medical records for 77 patients with pancreatic cystic neoplasms with mucin secretion were reviewed. Patients were divided into IPMN (n = 70) or MCN (n = 7) according to the presence of ovarian-type stroma, and clinicopathologic parameters were compared between groups.

RESULTS

IPMNs consisted of 32 adenomas, 12 borderline neoplasms, 13 adenocarcinomas in situ, and 13 invasive adenocarcinomas; MCNs included 6 adenomas and 1 invasive adenocarcinoma. The mean age of IPMN patients (66 years) was significantly older than that of MCN patients (55 years). The male:female ratio in IPMN (53/17) was significantly greater (P < .001) than in MCN (0/7). The location of the pancreatic mass differed, with 76% 0f IPMNs occurring in the head, while 86% of MCNs occurred in the body or tail. Mass mean size was significantly smaller (28 mm vs 78 mm, P < .001), and mean diameter of the main pancreatic duct was larger (6.8 mm vs 3.1 mm, P < .001) in IPMN than in MCN. Patulous papilla was present in 44% (31/70) of IPMNs, but none was present in MCNs. Communication between the cyst and main pancreatic duct was more frequent in IPMNs (67/70) than in MCNs (1/7). Overall 5-year survival rates were 84% (IPMN) and 100% (MCN).

CONCLUSIONS

Clinicopathologic differences between IPMN and MCN are much clearer when differentiated by presence of ovarian-type stroma. Favorable prognosis for both neoplasms is offered by complete resection.

Small cystic lesions of the pancreas: clinical significance and findings at follow-up

BACKGROUND

Our purpose was to correlate the imaging findings of small cystic pancreatic lesions to the incidence of growth on follow-up imaging and their pathologic diagnoses.

METHODS

CT images for 159 patients with cystic pancreatic lesions were retrospectively evaluated and lesions were assessed for size, number, connection to the main pancreatic duct (MPD), MPD dilatation, and any presence of loculation, wall irregularity, thick septations, or solid components. A total of 86 patients had follow-up imaging with time periods of less than 6 months (n = 21), 6-12 months (n = 22), 1-2 years (n = 14), and greater than 2 years (n = 29). Lesion histology was available in 20 patients.

RESULTS

Lesions with pathologic correlation proved to be: side branch intraductal papillary mucinous neoplasm or tumor (IPMT) (n = 5), combined type IPMT (n = 4), nonmucinous cyst (n = 4), chronic pancreatitis (n = 2), and reactive atypia with nonmucinous fluid (n = 1), combined type IMPT with foci of adenocarcinoma (n = 1), mucinous adenocarcinoma (n = 2), and nonmucinous adenocarcinoma (n = 1). Lesions with solid components were significantly more likely to grow and be malignant (P < 0.05). The presence of MPD dilatation was more common in patients with combined type IPMTs or malignancies. No other factors were predictive of malignancy.

CONCLUSIONS

Solid components are predictive of malignancy, and MPD dilatation should prompt consideration of surgery. Other cystic lesions can be followed.

MDCT of intraductal papillary mucinous neoplasm of the pancreas: evaluation of features predictive of invasive carcinoma

OBJECTIVE

The purpose of our study was to evaluate factors predictive of the presence of invasive carcinoma associated with intraductal papillary mucinous neoplasm (IPMN) of the pancreas on MDCT.

MATERIALS AND METHODS

Preoperative MDCT of 36 consecutive patients (23 men, 13 women; mean age, 66.6 years) who had undergone surgical resection and had a pathologic diagnosis of IPMN were retrospectively assessed. CT was performed with a 4-MDCT scanner with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Arterial and venous phase images were acquired at 25 and 50-60 sec from the start of IV contrast administration. Type of ductal involvement, location, tumor size in branch duct type and combined type lesions, caliber of the main pancreatic duct, caliber of the common bile duct or common hepatic duct, and solid appearance of the lesion were assessed on CT and correlated with pathologic findings for invasive carcinoma.

RESULTS

Pathologic analysis revealed carcinoma in situ in seven patients (19%) and invasive carcinoma in 15 patients (42%) arising from the IPMN. With invasive carcinoma, the size of the tumor in branch duct type and combined type, and the caliber of the main pancreatic duct were significantly larger compared with the lesions without invasive carcinoma (4.7 +/- 1.7 cm vs 2.6 +/- 1.4 cm [p = 0.0007] and 9.3 +/- 5.5 mm vs 4.6 +/- 4.1 mm [p = 0.006], respectively). A solid mass (p < 0.001), dilatation of the common bile duct or common hepatic duct (> or = 15 mm), and the presence of a stent (p = 0.0004) were correlated with the presence of associated invasive carcinoma.

CONCLUSION

MDCT helped to predict invasive carcinoma associated with IPMN.

Invasive carcinoma originating in an intraductal papillary mucinous neoplasm of the pancreas: a clinicopathologic comparison with a common type of invasive ductal carcinoma

OBJECTIVES

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is an indolent neoplasm by nature; however, it sometimes acquires invasive potential and has been classified as invasive IPMN. The aim of the present study was to investigate the clinicopathologic difference between invasive IPMN and a common type of invasive ductal carcinoma of the pancreas.

METHODS

Eighteen patients with invasive IPMN underwent pancreatectomy between 1992 and 2004. Clinical, biochemical, and histopathologic factors were retrospectively analyzed. The resulting data were compared with those of 274 patients with a common type of pancreatic ductal carcinoma who underwent surgery during the same period.

RESULTS

The total size of tumor of invasive IPMN, including cystic and invasive components, was statistically larger than that of a common type of invasive ductal carcinoma (62 vs 40 mm, P < 0.001), but the size of invasive component of invasive IPMN was smaller than that of a common type of invasive ductal carcinoma (21 vs 40 mm, P < 0.001). Negative lymph node metastases and relatively limited local tumor spreading were frequently observed in patients with invasive IPMN. On microscopic examination, the tumors infiltrating the surrounding tissue had a less invasive growth pattern, and a lower frequency of lymphatic invasion, venous invasion, and intrapancreatic neural invasion was also observed in patients with invasive IPMN. The 5-year survival rate of invasive IPMN was significantly higher than that of common-type invasive ductal carcinoma (42% vs 20%, P = 0.04).

CONCLUSIONS

An increased awareness of invasive IPMN has enabled pancreatectomies to be performed at an earlier stage, relative to that for ordinary pancreatic cancer. The less frequent detection of pathological factors concerned with tumor invasiveness in patients with invasive IPMN suggested the lower aggressive behavior of this tumor.

International consensus guidelines for management of intraductal papillary mucinous neoplasms and mucinous cystic neoplasms of the pancreas

Non-inflammatory cystic lesions of the pancreas are increasingly recognized. Two distinct entities have been defined, i.e., intraductal papillary mucinous neoplasm (IPMN) and mucinous cystic neoplasm (MCN). Ovarian-type stroma has been proposed as a requisite to distinguish MCN from IPMN. Some other distinct features to characterize IPMN and MCN have been identified, but there remain ambiguities between the two diseases. In view of the increasing frequency with which these neoplasms are being diagnosed worldwide, it would be helpful for physicians managing patients with cystic neoplasms of the pancreas to have guidelines for the diagnosis and treatment of IPMN and MCN. The proposed guidelines represent a consensus of the working group of the International Association of Pancreatology.

Intraductal papillary mucinous neoplasm of the pancreas: can benign lesions be differentiated from malignant lesions with multidetector CT?

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a distinct clinicopathologic entity that is being recognized with increasing frequency. In 25%-44% of IPMNs treated with surgical resection, associated invasive carcinoma has been reported. Surgical resection is the treatment of choice for most IPMNs. Preoperative determination of the presence or absence of associated invasive carcinoma is crucial. The prognosis is worse if there is associated invasive carcinoma; when invasive carcinoma is present, the surgical procedure may be modified to include resection of regional lymph nodes. The spectrum of appearances of IPMN, which includes adenoma, borderline lesion, and lesions with associated carcinoma in situ or invasive carcinoma, was studied with 16-section multidetector computed tomography (CT) and histologic correlation. CT was performed with dual-phase acquisition; the reconstructed images were reviewed on a workstation with axial scrolling and interactive multiplanar reformation and three-dimensional reformation techniques. Features predictive of invasive carcinoma in IPMN at CT and other imaging studies include involvement of the main pancreatic duct, marked dilatation of the main pancreatic duct, diffuse or multifocal involvement, the presence of a large mural nodule or solid mass, large size of the mass, and obstruction of the common bile duct.

Intraductal papillary mucinous neoplasm of pancreas: multi-detector row CT with 2D curved reformations--correlation with MRCP

PURPOSE

To retrospectively compare accuracy of multi-detector row computed tomography (CT), combined with two-dimensional (2D) curved reformations, and that of magnetic resonance (MR) cholangiopancreatography (MRCP) for characterization of intraductal papillary mucinous neoplasm (IPMN) as malignant, with pathologic examination as reference standard.

MATERIALS AND METHODS

Institutional review board approval was obtained, informed consent was waived, and study was HIPAA compliant. Twenty-five patients (12 women, 13 men; age range, 44-88 years) with pathologically proved IPMN were examined with dual-phase CT with 1.25-mm-thick sections for pancreatic phase; 2D curved reformations along main pancreatic duct (MPD) were generated. T2-weighted MRCP included thick- and thin-slab single-shot fast spin-echo imaging and transverse fast spin-echo imaging. Two radiologists, blinded to surgical and pathologic findings, evaluated images for lesion location, septa, mural nodules, communication with MPD, extent and diameter of MPD dilatation, calcifications, and vascular encasement. Malignancy was suspected when one of the following was present: MPD diameter larger than 10 mm, mural nodules, vascular encasement, peripancreatic lymphadenopathy, or metastases. Sensitivity and specificity values for prediction of malignancy were calculated for CT and MRCP. Interobserver variability was determined (kappa analysis).

RESULTS

Excellent correlation between modalities was observed. Cyst communication was seen in 20 and 21 of 24 branch pancreatic duct (BPD) IPMNs with CT and MRCP, respectively. Sensitivity, specificity, and accuracy for detection of malignancy were 70%, 87%, and 76% (CT) and 70%, 92%, and 80% (MRCP), respectively. Interobserver agreement was good to perfect for both readers in all comparisons (overall, kappa = 0.70-1.00).

CONCLUSION

CT combined with 2D curved reformation can provide imaging details of IPMN, including communication of BPD IPMN with MPD, that are almost equivalent to those provided at MRCP. Presence of mural nodules, dilated MPD (>10-mm diameter), or thick septa at CT or MRCP may be used as independent predictors of malignancy.

Clinicopathological features and medical management of intraductal papillary mucinous neoplasms

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMN) are a clinicopathological entity that is being diagnosed with increasing frequency. However, the best approach to medical management of IPMN needs to be clarified. The aim of the present study was to identify preoperative features that may be predictors of malignant IPMN, and to define the medical management of IPMN of the pancreas.

METHODS

A total of 23 patients who underwent surgical resection for IPMN of the pancreas at Kochi Medical School between 1982 and 2004 were examined. Multivariate Cox regression analysis was used to identify factors independently associated with IPM carcinoma.

RESULTS

Among the 23 patients, 12 had IPMN adenoma, three had borderline IPMN, four had IPMN with carcinoma in situ, and four had IPMN with invasive carcinoma. In multivariate analysis, elevated serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 levels were found to be preoperative predictors of malignant IPMN. These results suggest that the following IPMN of the pancreas should be resected: (i) IPMN of the pancreas situated in the main duct; (ii) IPMN located in the branch duct if the size of the cystic lesion is >30 mm and the mural nodules are >5 mm in height by endoscopic ultrasound (EUS); and (iii) the diameter of the main pancreatic duct is >10 mm by endoscopic retrograde pancreatography (ERP). Careful observation of patients with branch-type IPMN with small cysts and/or without mural nodules is recommended as a management strategy.

CONCLUSION

The present study reinforces the need for immediate surgical resection of malignant IPMN and suggests indicators for IPMN that should assist physicians in making decisions on treatment options.

Magnetic resonance imaging in the detection of pancreatitis and pancreatic neoplasms

This article presents current magnetic resonance imaging techniques for the diagnosis of acute and chronic pancreatitis and pancreatic neoplasms. It emphasises the need for a comprehensive protocol combining imaging sequences of the pancreatic parenchyma with magnetic resonance angiography and secretin-enhanced magnetic resonance cholangiopancreatography in order to evaluate the full range of pancreatic inflammatory and neoplastic conditions. Imaging characteristics that may indicate a specific diagnosis are discussed.

Frozen sectioning of the pancreatic cut surface during resection of intraductal papillary mucinous neoplasms of the pancreas is useful and reliable: a prospective evaluation

OBJECTIVE

To prospectively evaluate the accuracy of frozen sectioning (FS) of the pancreatic transection margin and its influence on surgery during resection of intraductal papillary and mucinous neoplasms (IPMNs).

SUMMARY BACKGROUND DATA

Preoperative assessment of IPMN extension is difficult and transection margin is frequently tumoral on the surgical specimen.

PATIENTS AND METHODS

FS was performed in 127 patients who underwent partial pancreatectomy for IPMN from 1996 to 2004, corresponding to 90 pancreaticoduodenectomies (1-4 successive FS; total = 132), 25 distal pancreatectomies (1-2 FS; total = 27), and 12 medial pancreatectomies (2-4 FS; total = 29). Dysplasia was graded in both main (MD) and branch ducts (BD), and pancreatectomy was extended if FS revealed at least IPMN adenoma on the MD or borderline IPMN on BD (defined as "significant" lesions).

RESULTS

The 188 FS revealed that MD and BD epithelium comprised significant noninvasive lesions in 49 and 13 cases, respectively, and infiltrating carcinoma in 4 other ones. Definitive examination corroborated FS in 176 of 188 cases (94%). Altogether, 54 of 188 (29%) FS comprised significant lesions that resulted in 46 additional resections in 38 patients (30%). Eight patients did not have additional resection because of either high operative risk or preoperative diagnosis of noncurable infiltrating carcinoma. The 134 FS without significant lesions were associated with 7 additional resections mainly because of macroscopic suspicion of another tumor location. Conflicting results between FS and definitive examination resulted in inadequate extent of pancreatectomy in 4 patients (3%).

CONCLUSIONS

Results of FS of the transection margin are confirmed by definitive examination in 94% of cases. According to our protocol, FS changes the extent of resection in 30% of patients and allows adequate resection in 97% of patients.

Multidetector CT of the pancreas

CT is the primary imaging modality of the pancreas. This article reviews the multidector CT technique and its current status in the diagnosis of various pancreatic diseases. Special emphasis is given to the impact of multidetector CT and postprocessing imaging techniques on the staging of pancreatic adenocarcinoma.

Intraductal papillary mucinous neoplasms of the pancreas

The introduction of the exocrine pancreatic classification by the World Health Organization and improvements in pancreatic imaging have led to an improved understanding of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. As a result, IPMNs of the pancreas are increasingly being recognized as a separate disease entity. IPMNs are characterized by the cystic dilatation of the pancreatic duct and its branches, with papillary projections. There are three histological subtypes of IPMNs: main duct, branch duct, and mixed. The degree of atypia ranges from adenoma to frank invasive carcinoma. The lymph nodes are involved considerably less frequently than they are in pancreatic adenocarcinoma. Most patients are symptomatic at diagnosis and require a diagnostic workup similar to that for patients with pancreatic adenocarcinoma. Although some investigators continue to advocate total pancreatectomy, the evidence in support of this is decreasing. Partial pancreatectomy remains the treatment option. Intraoperative assessment of the resection surgical margins is an important component of surgical resection. Additionally, controversy also exists regarding the nature of the follow-up and the need for adjuvant chemoradiation therapy in the patient. Unlike ductal adenocarcinomas, IPMNs follow a relatively indolent course; the 5-year survival rate in patients with invasive IPMNs is 57%. A mural nodule and a main pancreatic duct diameter greater than 5 mm have been found to be predictors of malignancy.

Intraductal papillary mucinous neoplasms of the pancreas: A surgical perspective

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas represent a relatively "new", but increasingly recognized entity. The emergence of this entity is due primarily to the widespread use of modern imaging methods, but also to a heightened awareness of physicians regarding this cystic neoplasm of the pancreas. No signs or symptoms are pathognomonic of IPMNs, but frequently, patients have a pancreatitis-like abdominal pain. Fully one-third of patients with IPMN are asymptomatic at the time of diagnosis. Cross-sectional imaging (ultrasonography, computed tomography, magnetic resonance cholangiopancreatography), endoscopic retrograde cholangiopancreatography, and endoscopic ultrasonography are the diagnostic and staging methods of choice in the evaluation of patients with IPMNs. IPMNs show a wide spectrum of histologic changes, ranging from adenoma to invasive neoplasm, even within the same neoplasm, suggesting a "field defect" predisposing major segments or even the entire ductal epithelium to the development of IPMN. Fine-needle aspiration/cytology and/or analysis of the cystic fluid may be useful diagnostic tools; however, these examinations are associated with high false-negative rates. Complete surgical resection is the therapeutic method of choice. The extent and type of pancreatectomy remain somewhat controversial but should be based on morphologic changes of the pancreas. Even the role of adjuvant therapy remains unclear; however, being "duct-derived" neoplasms of potential malignant character, some form of adjuvant chemo- or ratio-therapy seems indicated in the presence of invasive disease, despite a "curative" resection. In the absence of invasive disease, prognosis after R0 resection is highly favorable with recurrences of 5-10%. However, invasive IPMNs behave quite similar to ductal adenocarcinoma of the pancreas when analyzed stage-by-stage, with a slightly better prognosis; however, even after an R0 resection, recurrence is common.

Long-term follow-up of intraductal papillary mucinous neoplasm of the pancreas with ultrasonography

BACKGROUND & AIMS

Most intraductal papillary mucinous neoplasms of the pancreas (IPMNs) have a favorable prognosis. This study was undertaken to clarify the clinical course of IPMNs and to set the criteria for surgical treatment on the basis of long-term follow-up by periodic transabdominal ultrasonography (US).

METHODS

Eighty-one patients with IPMN were periodically subjected to US (>3 years); 27 were reviewed retrospectively (12 with benign neoplasms [adenoma, borderline] and 15 with malignant tumors [carcinoma in situ, invasive cancer]) and 54 prospectively. US examination was focused on the main pancreatic duct (MPD) diameter, cyst diameter, and presence or absence and height of the protruding lesion. Differences between the benign and malignant groups were examined to set the criteria for surgical treatment. Follow-up results of prospective patients were investigated.

RESULTS

The increase of the MPD or the cyst diameter was significantly greater in the malignant group (P < .01). Maximum increases of the MPD diameter by 2.2 mm/year, the cyst diameter by 11.3 mm/year, and emergence or increase of the height of the protruding lesion by 3.3 mm/year were predominantly observed in the malignant group (accuracy, 90.9%, 81.3%, and 81.5%, respectively). The majority of the prospective patients showed no significant changes of these parameters; however, 2 patients (3.7%) were operated on, with the post-surgery histopathologic diagnosis of cancer.

CONCLUSIONS

Periodic imaging follow-up is useful to detect a malignant IPMN. Changes in MPD diameter, cyst diameter, and/or size of the protruding lesion are the practical criteria for selecting surgery.

Intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a new pathological entity. It is diagnosed with increasing frequency. However, its natural history and management are still not well defined.

METHODS

A Medline search was undertaken to identify articles using the keywords "intraductal papillary mucinous neoplasms of pancreas", "pancreatic neoplasms", and "pancreatic cyst". Additional papers were identified by a manual search of the references from the key articles.

RESULTS

Surgical resection is the only treatment which can produce a cure. The reported overall 5-year survival for IPMN after surgical resection varies from 36% to 77%; for non-invasive IPMN, 77% to 100% and for invasive IPMN, 27% to 60%. The overall recurrence rate was 7% to 43%. IPMN can recur either as disseminated disease or as isolated pancreatic remnant recurrence even after surgical resection with negative margins.

CONCLUSIONS

Based on the available evidence, patients with IPMN should undergo complete surgical resection. The extent of pancreatic resection and the intra-operative management of resection margins remain controversial. Balancing the risk of recurrence and the morbidity of total pancreatectomy, routine total pancreatectomy for IPMN is not recommended. Total pancreatectomy should only be reserved for patients with resectable but extensive IPMN which involves the whole pancreas. Regular monitoring for disease recurrence is important after surgery as there is a risk of recurrence in both non-invasive and invasive IPMN, and repeat resection for an isolated recurrence in the pancreatic remnant gives good results.

[Intraductal neoplasms of the pancreas: cystic and common]

The most important of the generally rare intraductal tumors of the pancreas is the intraductal papillary-mucinous neoplasm (IPMN). In recent years this tumor type has been described in detail, and it was included in the WHO classification of 1996. IPMNs typically grow for a long time within the ducts, before approximately 50% of them eventually become invasive. Because of this feature the IPMNs are clearly distinct from ductal adenocarcinomas. Currently, IPMNs have advanced to the most commonly resected cystic tumor of the pancreas. Recent studies have shown that IPMNs may be distinguished into different types showing a different biology according to their mucin pattern.

Outcomes following resection of invasive and noninvasive intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

Since any intraductal papillary mucinous neoplasm (IPMN) is at least premalignant, avoiding conversion to invasion by pancreatic resection should provide a survival advantage-but how much?

METHODS

We reviewed 100 cases of IPMN that were resected. Survival was compared between 3 groups: noninvasive IPMN (n = 75), invasive IPMN (n = 25), and invasive ductal adenocarcinoma (n = 24), the latter matched by tumor-node-metastasis (TNM) stage to the IPMN invasive group.

RESULTS

The 5-year disease-specific survival was significantly better for the noninvasive IPMN group (100%) than the invasive IPMN group (46%). Tumor recurrence was infrequent with noninvasive IPMNs (1.3% benign IPMN). Recurrence was common in the invasive IPMN group (46%). Even the subgroup with stage 1 disease had a 25% recurrence of malignancy. Survival curves were not different (P = .11) between the cases matched by stage for those with invasive IPMN cases versus cases with ductal adenocarcinoma.

CONCLUSION

Patients with the invasive form of IPMN will have a similarly poor survival as those with ductal adenocarcinoma. In patients thought to have a benign IPMN, these lesions should be removed to avoid conversion to invasive cancer and to preserve the opportunity for the more favorable prognosis observed in this study.

Aspect radiologique des tumeurs intracanalaires pancréatiques mucineuses et papillaires

IPMTP is a pancreatic duct disease that can better be diagnosed due to advances in imaging techniques. This probably explains the recent increased frequency of this disease. Enlargement of the main pancreatic duct and/or branch ducts is a typical feature. CT and MRI with MRCP are useful for diagnosis. Features of malignant degeneration are better known. Preoperative staging is performed at CT. Differential diagnosis includes main pancreatic duct dilatation and pancreatic cysts. Recent papers indicate that isolated side branch IPMTP is less frequently malignant. Surgery is indicated in the presence of acute pancreatitis or suspicion of malignant degeneration. Imaging is useful for the follow up of patients with isolated side branch IPMTP. In this paper, the diagnostic, staging and malignant features of IPMTP will be reviewed.