Diagnosis of carcinoma in situ of the pancreas by peroral pancreatoscopy and pancreatoscopic cytology

Predictors of malignancy in main duct intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND AND AIMS

The International Consensus Guidelines updated in 2017 recommended surgery to all main duct intraductal papillary mucinous neoplasms (MD-IPMNs) with the main pancreatic duct (MPD) of 10 mm or more and those with mural nodules regardless of size. The aim of the present study was to identify predictors of malignancy in MD-IPMN among preoperative factors including MPD and mural nodule size.

METHODS

Twenty-six benign MD-IPMNs (7 resected and 19 nonresected) and 32 malignant MD-IPMNs (31 resected and 1 nonresected) were included in the study. MRCP, CT, EUS, and cytology were performed using pancreatic juice collected by endoscopic retrograde pancrestography (ERP). Resected IPMNs were classified as benign or malignant by histologic examination and nonresected MD-IPMNs by imaging, cytology, and observation. Cutoff values of candidate parameters were determined by receiver operating characteristic curves. Univariate and multivariate analyses by regression model were performed.

RESULTS

MPD and mural nodule size and cytology results differed significantly between benign and malignant groups. Cutoff values of MPD and mural nodule sizes were 15 mm and 10 mm with areas under the curve of .66 and .86, respectively. Mural nodules of 10 mm or more (odds ratio, 8.32; 95% confidence interval, 1.13-61.2; P = .038) and positive cytology (odds ratio, 42.5; 95% confidence interval, 4.10-439; P = .002) were shown to be independent predictors of malignancy by multivariate analysis. When MD-IPMNs with either predictor were diagnosed to be malignant, sensitivities, specificities, and overall accuracy for malignancy were 94%, 85%, and 90%, respectively.

CONCLUSIONS

Mural nodules of 10 mm or more and positive cytology were independent predictors of malignancy in MD-IPMN.

Risk factor, early diagnosis and overall survival on outcome of association between pancreatic cancer and diabetes mellitus: Changes and advances, a review

To review literature addressing determination of the risk factor, early diagnosis and overall survival on outcome among patient of pancreatic cancer associated with diabetes mellitus from the perspective of pancreatic surgery. To identify recent guidelines, clinical pathogenesis, pathological classification, screening methodology and advances in surgical management. It identifies those clinical and surgical variables to predict excellent prognosis in respect of life style changes, ongoing advancement in therapeutic and surgical treatment and postoperative follow up. Approximately 85% pancreatic cancer have impaired glucose tolerance and may be associated with diabetes mellitus. Diabetes improves following pancreatic resection. This suggest diabetes is caused by pancreatic cancer. New onset glucose intolerance or DM is an earliest manifestation of pancreatic cancer. Recognition of new onset diabetes as an early manifestation of pancreatic cancer leads to diagnosis of asymptomatic, early stage pancreatic cancer. Thus, helps to aid in better diagnosis and therefore prolonging survival rate. Increasing duration of diabetes mellitus is significantly associated with decreasing risk of pancreatic cancer. Elderly patient with new onset diabetes have high risk of having pancreatic cancer compared to general population. New onset hyperglycemia and diabetes serves as an important screening tool to diagnose asymptomatic pancreatic cancer patient and improves pancreatic cancer related survival. DM in association with pancreatic cancer have reduced overall survival rate and increased mortality. Despite of having dismal prognosis of pancreatic cancer, many studies have concluded the survival rate of 5 years. There exists a bidirectional association between pancreatic cancer and DM is found to be a cause of pancreatic cancer as well as complication. The study on pancreatic cancer and diabetes has offered an interesting field of research based study and surgical practices.

Role of per-oral pancreatoscopy in the evaluation of suspected pancreatic duct neoplasia: a 13-year U.S. single-center experience

BACKGROUND AND AIMS

The role of per-oral pancreatoscopy (POP) in the evaluation of occult pancreatic duct (PD) lesions remains limited to case series. The aim of this study was to evaluate the ability of POP to differentiate malignant from benign diseases of the PD.

METHODS

Patients who underwent POP between 2000 and 2013 for the evaluation of indeterminate PD strictures, dilatations, or with suspected or known main duct intraductal papillary mucinous neoplasm were identified. Main outcome measurements were visual impression accuracy, POP tissue sampling, efficacy, and safety of POP.

RESULTS

During the study period, 79 patients who underwent POP for the evaluation of pancreatic stricture or dilatation were identified. Technical success was achieved in 78 (97%). In the PD neoplasia group (n = 33), the final diagnosis was based on index confirmatory POP-guided tissue sampling in 29 (88%). For the detection of PD neoplasia, POP visual impression had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 87%, 86%, 83%, 91%, and 87%, respectively. When combined with POP-guided tissue sampling, the values were 91%, 95%, 94%, 93%, and 94%, respectively. Of 102 POPs performed, adverse events were noted in 12 (12%) cases.

CONCLUSIONS

This study demonstrates a high technical success rate, visual impression accuracy, and tissue sampling capability of POP. Examinations were performed by endoscopists with expertise in pancreatoscopy interpretation, and the results may not be generalizable.

Pancreatic juice cytology as sensitive test for detecting pancreatic malignancy in intraductal papillary mucinous neoplasm of the pancreas without mural nodule

OBJECTIVE

Recent studies reported that mural nodule (MN) was the most associated with malignant intraductal papillary mucinous neoplasms (IPMNs). However, IPMNs without MN cannot be diagnosed as malignant if only MN is determined to be indicator of malignancy. This study aimed to investigate role of pancreatic juice cytology for IPMNs without MN.

METHODS

Medical records of 50 patients with histologically proven malignant IPMNs were reviewed. Exclusively for non-invasive cancer, extent of high-grade dysplasia along the main pancreatic duct (MPD) was determined microscopically.

RESULTS

Thirty-six percent IPMNs had no MN. Cyst and main MPD diameter were significantly smaller in IPMN without MN compared to those in IPMN with MN (23 ± 14.1 vs 35 ± 13.2 mm, p = 0.010; 6.6 ± 4.3 vs 10.9 ± 6.1 mm, p = 0.006). Sensitivity of pancreatic juice cytology was higher in IPMN without MN compared to that in IPMN with MN (94% vs 53%, p = 0.004) although it could be affected by selection bias of study patients. Absence of MN was determined to be an independent factor associated with true positive cytology (OR = 24.3, p = 0.005). Extent of high-grade dysplasia was significantly longer in IPMN with true positive cytology compared to that in IPMN with false negative cytology (46.8 ± 20.5 vs 26.4 ± 11.0 mm, p = 0.005), and tended to be longer in IPMN without MN compared to that in IPMN with MN (47.0 ± 19.0 vs 36.0 ± 20.1 mm, p = 0.16).

CONCLUSIONS

Sensitivity of pancreatic juice cytology was excellent in IPMN without MN. Pancreatic juice cytology may be a sensitive test for detection of pancreatic malignancy in IPMN without MN compared to high-risk imaging features.

Malignant transformation of branch duct-type intraductal papillary mucinous neoplasms of the pancreas based on contrast-enhanced endoscopic ultrasonography morphological changes: focus on malignant transformation of intraductal papillary mucinous neoplasm itself

OBJECTIVES

The natural history of branch duct-type intraductal papillary mucinous neoplasms (BD-IPMNs) of the pancreas remains unclear. We conducted a retrospective long-term follow-up study for malignant transformation (MT) of BD-IPMNs focusing on morphological changes.

METHODS

The subjects consisted of 142 patients who underwent contrast-enhanced endoscopic ultrasonography for initial diagnosis from January 2001 with more than 12 months of follow-up. The MT rate, including the co-occurrence of invasive ductal cancer, was evaluated by univariate and multivariate analysis. In addition, on the basis of morphological changes in patients who underwent surgery, the predictive factors for malignant IPMNs were evaluated.

RESULTS

Median follow-up term was 42.5 months (range, 12-105 months). Thirty patients who exhibited morphological changes underwent surgery. Malignant transformation occurred in 9 patients (6.3%), and 5-year MT rate was 10.7%. The co-occurrence of invasive ductal cancer was seen in 5 patients. Multivariate analysis showed that the existence of mural nodules at initial diagnosis and involvement of main pancreatic duct were significant predictors of MT of BD-IPMN.

CONCLUSIONS

Malignant transformation of BD-IPMN is not rare. The observation of morphological changes of main pancreatic duct and nodules, mainly on contrast-enhanced endoscopic ultrasonography, is practical and useful for predicting MT of BD-IPMN itself.

A nomogram for predicting the probability of carcinoma in patients with intraductal papillary-mucinous neoplasm

BACKGROUND

The objective of the present study was to use clinical and laboratory data to develop a model for predicting the presence of carcinoma in patients with intraductal papillary mucinous neoplasm (IPMN).

METHODS

Data were collected on 81 patients with IPMN who underwent a pancreatic resection between 1989 and 2008 at Aichi Cancer Center Hospital. Variables analyzed included age, gender, laboratory findings (serum amylase, carcinoembryonic antigen, and carbohydrate antigen 19-9 level), pancreatic juice cytology grade, and imaging studies. Factors associated with the presence of carcinoma were evaluated by univariate and multivariate logistic regression analysis.

RESULTS

Among the 81 patients with IPMN, 34 (42%) had malignant tumors (noninvasive carcinoma in 22 and invasive carcinoma in 12), and 47 (58%) had adenoma. On multivariate analysis, existing carcinoma was associated with female gender, main pancreatic duct IPMN, nodule size, and pancreatic juice cytology grade. Based on these variables, a predictive nomogram was developed. The area under the receiver operating characteristic curve (AUC) for the model was 0.903. The sensitivity and specificity of the model were 97.1 and 68.1%, respectively, in the validation study, for which the predictive probability of >10% was used to indicate the presence of carcinoma.

CONCLUSIONS

The nomogram has high diagnostic predictability for carcinoma in patients with IPMN and for individual cancer probability. This instrument may help to identify patients who need a surgical procedure.

A natural course of main duct intraductal papillary mucinous neoplasm of the pancreas with lower likelihood of malignancy

OBJECTIVES

Main duct intraductal papillary mucinous neoplasms (IPMNs) of the pancreas include neoplasms with varying likelihood of progression to malignancy. The aim of this study was to investigate a natural course of main duct IPMNs with a lower likelihood of malignancy.

METHODS

Twenty main duct IPMNs with a lower likelihood of malignancy, which was defined as mural nodule of less than 10 mm or no visualized mural nodule, and negative result of cytological examination of pancreatic juice, underwent regular ultrasound every 3 months. Special imaging examinations and additional pancreatic juice cytological examination were performed when necessary. Surgery was considered when a mural nodule enlarged to 10 mm or the cytological examination result indicated malignancy.

RESULTS

During a mean of 70 months, 12 IPMNs (60%) did not progress and 6 (30%) progressed within a lower likelihood of malignancy. The remaining 2 IPMNs (10%) progressed to meet the criteria for resection, underwent surgery, and were demonstrated to be carcinomas.

CONCLUSIONS

Main duct IPMN with a lower likelihood of malignancy was divided into 2 subgroups: neoplasm that progressed and that which did not progress during its natural course. The former should be resected considering its malignant potential, whereas the latter may be managed nonsurgically as long as it stays unchanged.

Cytopathology of the pancreas: neoplastic and nonneoplastic entities

Endoscopic ultrasound-directed fine-needle aspiration is a minimally invasive technique for the biopsy of pancreatic cysts and mass lesions. The technique is associated with low morbidity and high diagnostic accuracy. Interpretation of cytologic material obtained from the pancreas is complex because of the large number of reactive processes and benign and malignant neoplasms arising within the pancreas. The cytologic appearances of a majority of pancreatic neoplasms are characteristic, allowing precise recognition of the type of neoplasm present. Whereas separation of neuroendocrine, acinar, and ductal neoplasms is usually straightforward, the greatest diagnostic challenge in pancreatic fine-needle aspiration is the separation of atypical epithelium secondary to chronic pancreatitis from well-differentiated ductal adenocarcinoma. Recently, a number of in situ lesions have been identified, complicating the cytologic diagnosis of pancreatic neoplasia. These noninvasive lesions include pancreatic intraepithelial neoplasia and intraductal papillary mucinous neoplasm.

Cholangiopancreatoscopy for targeted biopsies of the bile and pancreatic ducts

Establishing a tissue diagnosis in patients with suspected pancreaticobiliary malignancies remains challenging. Endoscopic retrograde cholangiopancreatography (ERCP)-based sampling methods have been reviewed in a previous issue of this journal but, unfortunately, the diagnostic yield continues to be inadequate in a significant minority of patients. The availability and image quality of cholangioscopy and pancreatoscopy have advanced in the last few years and our ability to make a diagnosis on imaging alone is improving. However, a definitive diagnosis requires tissue; cholangiopancreatoscopy allows targeted biopsies of the epithelium of the biliary and pancreatic ducts. This article reviews the evidence that cholangioscopy- and pancreatoscopy-guided biopsies improves diagnostic yield over ERCP-based tissue sampling techniques.

Peroral pancreatoscopy in the diagnosis and management of intraductal papillary mucinous neoplasia and indeterminate pancreatic duct pathology

Peroral pancreatoscopy (POP) is an exciting modality for the evaluation of pancreatic diseases. It has proved efficacy in the evaluation of suspected intraductal papillary mucinous neoplasia and allows for a determination of the presence and extent of pancreatic duct involvement. When other imaging modalities are inconclusive, POP seems a useful adjunct in the evaluation of indeterminate pancreatic duct strictures and permits tissue sampling under direct vision. Despite recent advances, refinements in endoscope caliber, tip deflection, and optics are still required for more routine application in pancreatic diseases.

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.

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.

Quantitative analysis of hTERT mRNA levels in cells microdissected from cytological specimens

Clinicians frequently require cytopathological assessment of tumor samples for preoperative diagnosis, but in some specimens, diagnosis remains inconclusive after cytological examination. To date, several molecular markers, including human telomerase reverse transcriptase (hTERT), have been assessed for the ability to detect malignancy. However, analyses using whole cytological specimens are generally affected by contamination of untargeted cells. The present study investigated the feasibility of more sensitive examination by quantitative mRNA analysis of target cells microdissected from cytological specimens. Laser capture microdissection (LCM) was used to obtain target cells from cytological specimens. hTERT mRNA levels were then measured in target cells by quantitative real-time RT-PCR (qRT-PCR). The effect of RNA fragmentation on qRT-PCR was also assessed. Total RNA from cytological specimens was sometimes fragmented to a large degree. To avoid the effect of RNA fragmentation, gene specific priming and PCR primers generating short PCR products were used and no difference in delta Ct values between fragmented and non-fragmented RNA were found. hTERT mRNA levels were measured in cells microdissected from 33 cytological specimens. The levels of hTERT mRNA were significantly higher in malignant cases compared to those in non-malignant cases (P = 0.0003). The sensitivity was 96.2%, even when the specificities were 100%. High levels of hTERT mRNA were also found in three cases that were not diagnosed as malignant by cytological examination. Quantitative assessment of hTERT mRNA levels in cells microdissected from cytological specimens is a potential diagnostic tool to potentiate cytological examination in diagnosing malignancy.

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.

Intraductal biliary and pancreatic endoscopy: An expanding scope of possibility

Intraductal endoscopy describes the use of an endoscope to directly visualize the biliary and pancreatic ducts. For many years, technological challenges have made performing these procedures difficult. The “mother-baby” system and other various miniscopes have been developed, but routine use has been hampered due to complex setup, scope fragility and the time consuming, technically demanding nature of the procedure. Recently, the SpyGlass peroral cholangiopancreatoscopy system has shown early success at providing diagnostic information and therapeutic options. The clinical utility of intraductal endoscopy is broad. It allows better differentiation between benign and malignant processes by allowing direct visualization and targeted sampling of tissue. Therapeutic interventions, such as electrohydraulic lithotripsy (EHL), laser lithotripsy, photodynamic therapy, and argon plasma coagulation (APC), may also be performed as part of intraductal endoscopy. Intraductal endoscopy significantly increases the diagnostic and therapeutic yield of standard endoscopic retrograde cholangiography (ERCP), and as technology progresses, it is likely that its utilization will only increase. In this review of intraductal endoscopy, we describe in detail the various endoscopic platforms and their diagnostic and clinical applications.

Pancreatogram findings for carcinoma in situ (CIS) of the pancreas seen on endoscopic retrograde cholangiopancreatography and postoperative pancreatography of resected specimens: can CIS be diagnosed preoperatively?

BACKGROUND/AIMS

From 1992 to 2003, 7 carcinomata in situ (CIS) were incidentally discovered during microscopical observation of resected materials for advanced carcinomas of peripancreatic organs, of which 4 had undergone endoscopic retrograde cholangiopancreatography (ERCP) or postoperative pancreatography of the resected specimen (POP). In addition, 7 of 79 invasive ductal carcinomata (IDC) of the pancreas were accompanied by CIS > or =2 cm long. A total of 11 patients were reviewed here for pancreatographic findings for CIS of the pancreas.

METHODS

All resected pancreatobiliary materials were sliced serially at 5- to 8-mm intervals in a plane at right angles to the main pancreatic duct, referring to POP images.

RESULTS

Irregularity (I), non-continuous narrowing (N), granular defects (G), and dilatation (D) were seen in 78, 67, 33 and 22% on ERCP, respectively, and in 90, 70, 60 and 40% on POP, respectively.

CONCLUSIONS

I, N, G, and D are most important pancreatographic findings in ERCP and highly suggestive of CIS of the pancreas, so that whenever they are encountered, cytological and/or pathological examination of the pancreatic duct should be actively performed.

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.

Review of the cytologic features of noninvasive ductal carcinomas of the pancreas: differences from invasive ductal carcinoma

Invasive ductal adenocarcinoma (IDA) of the pancreas (IDAP) originating from the ductal gland has a poor prognosis. Noninvasive carcinomas are principally intraductal papillary mucinous carcinomas (IPMCs) and pancreatic intraepithelial neoplasms 3 (PanIN-3). Small papillary-cohesive clusters, individually well-enveloped nuclei in well-preserved cytoplasm, centrally located nuclei, small nuclei (about 10 mum), euchromatin, clearly defined cell borders, small cytoplasm without prominent anisocytosis and no cytoplasm more than 21 mum in shortest diameter, a mixture of goblet cells, and a pleomorphic aspect are common in IPMC and intraductal papillary mucinous neoplasm (IPMN), whereas malignancy in nuclei are observed only in IPMC. PanIN-3 cells have small papillary-cohesive and compact clusters, a monomorphic aspect, and small dense cytoplasm and are highly suggestive of malignancy. IDA cells have loose sheet and solid clusters, poorly preserved cytoplasm, nuclei that tend to adhere to each other, large nuclei, a combination of large nuclei (short diameter <15 mum) with hyperchromatin, a monomorphic aspect, and abundant cytoplasm more than 21 mum in the shortest diameter. To preoperatively differentiate noninvasive IPMC and PanIN-3 from IDAP, these features would be clinically very useful.

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.

Endoscopic evaluation of the pancreatic duct system: opportunities offered by novel technology

The development of front-line endoscopic technology has introduced new opportunities during endoscopic retrograde cholangiopancreatography (ERCP) to single-handedly allow direct inspection of detailed structures of the biliary and even the pancreatic duct. This paper presents a new flexible technology delivered with an outer diameter of 0.9 mm giving an image transmission of 6000 pixels. We report on a case where direct inspection of an alleged duct defect, of potential pathogenetic significance, was considered essential in order to substantiate the subsequent clinical management.

Pancreatoscopy: present and future role

Current imaging modalities do not allow for direct access to the pancreatic duct. Because of this limitation, diagnosis and assessment of pancreatic diseases require radiographic imaging and cytologic analysis. Although many of these techniques have excellent specificity for the detection of pancreatic cancer, they offer no therapeutic capabilities and are relatively poor in early detection of cancer and in differentiating chronic pancreatitis from malignancy, particularly when the conditions coexist. Currently available cholangioscopes are too large to access the pancreatic duct without sphincterotomy or balloon dilation, increasing the risk of instrumentation trauma to the pancreas. Novel, dedicated pancreatoscopes have recently been developed and are under investigation in clinical trials. Preliminary evidence suggests that these new technologies allow for direct visualization of the pancreatic ducts, with the potential for forceps biopsy in suspected malignancy and endotherapy for pancreatic calculi. Future and ongoing clinical trials will better define the utility and roles of these new endoscopy tools.

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.

Pancreatic juice cytology in the diagnosis of intraductal papillary mucinous neoplasm of the pancreas: significance of sampling by peroral pancreatoscopy

BACKGROUND

The examination of pancreatic juice cytology could hypothetically contribute to the establishment of a definite diagnosis of malignant intraductal papillary mucinous neoplasm of the pancreas (IPMN), but to the authors' knowledge, its significance has not been confirmed to date. The current study was conducted to assess the diagnostic value of pancreatic juice cytology in IPMN and to examine the usefulness of peroral pancreatoscopy (POPS) in sampling pancreatic juice.

METHODS

The study subjects were comprised of 103 patients with IPMN who underwent surgical resection of pancreatic tumors (adenoma in 29 patients, borderline in 17 patients, carcinoma in situ in 25 patients, and invasive carcinoma in 32 patients). Pancreatic juice was collected with a catheter in 71 patients and by POPS in 32 patients. Patients with pancreatic carcinoma (n = 81) and chronic pancreatitis (n = 76) also were investigated.

RESULTS

The cytologic diagnosis was found to be of nondiagnostic value in only one patient with an IPMN, whereas it was of no diagnostic value in 14 of the patients with pancreatic carcinoma (17.3%), a difference that was statically significant (P < 0.001). The location of the IPMN (either in the pancreas or the pancreatic ducts) was not found to significantly affect the diagnostic value of the test. The sensitivity for IPMN was 62.2% when pancreatic juice was collected by POPS, and was 38.2% when it was collected using a catheter. In the case of pancreatic carcinoma, the sensitivity of pancreatic juice cytology was found to be 25.4%, which was significantly lower than that for IPMN when the pancreatic juice was collected by POPS (P < 0.001).

CONCLUSIONS

Pancreatic juice cytology was found to have better diagnostic value in the patients with IPMNs compared with those with pancreatic carcinoma. POPS was found to be useful for the collection of pancreatic juice.

Clinical aspects of intraductal papillary mucinous neoplasm of the pancreas

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

Initial experience with a new peroral electronic pancreatoscope with an accessory channel

BACKGROUND

A peroral electronic pancreatoscope was previously developed to improve visualization of the pancreatic duct, but this instrument had no accessory channel.

METHODS

A new peroral electronic pancreatoscope (2.6-mm external diameter) with an accessory channel (0.5 mm) was developed. Peroral pancreatoscopy or cholangioscopy was performed with this new instrument in 11 patients with various pancreatobiliary diseases. The clinical utility of the new peroral electronic pancreatoscope was assessed, and visualization with this new instrument was compared with that of the prototype.

RESULTS

The resolution of the two instrument systems was nearly equal, with that provided by the new peroral electronic pancreatoscope being slightly better. The new peroral electronic pancreatoscope was inserted successfully into the pancreatic or bile duct in 9 of the 11 patients (82%). Observation of a predetermined target and juice collection with direct visualization was successful in 8 of the 9 patients (89%).

CONCLUSIONS

The new peroral electronic pancreatoscope with an accessory channel was useful for clinical diagnosis of various pancreatobiliary diseases. Visualization is excellent. Pancreatic juice and other samples can be collected under direct visualization.

Endoscopic approach to early diagnosis of pancreatic cancer

Since its development, endoscopic retrograde cholangiopancreatography (ERCP) has been playing a major role in the diagnosis of pancreatic diseases. The recent development of magnetic resonance cholangiopancreatography has accelerated the shift in the role of ERCP toward more therapy-oriented applications. In the diagnosis and treatment of curable pancreatic cancer, however, ERCP remains the mainstay of imaging modalities. ERCP is not simply a method with which to obtain x-ray images of the pancreatic duct. Collection of pure pancreatic juice, transpapillary biopsy/brush cytology of the pancreatic duct, intraductal ultrasonography, and peroral pancreatoscopy are all performed based on the ERCP technique. Endoscopic ultrasonography (EUS) has a high spatial resolution and provides tomographic images of the pancreas and its neighboring organs. EUS is now widely used in evaluation of the local extent of pancreatic cancer and the differential diagnosis of cystic lesions of the pancreas. EUS-guided fine needle aspiration biopsy/cytology is performed to obtain a histologic diagnosis before beginning chemotherapy. Although the number of pancreatic cancer patients who are candidates for surgery is limited at present, there is an increasing need for ERCP-based techniques in both the diagnosis and treatment of pancreatic neoplasms.

Direct cholangioscopy and pancreatoscopy

Direct cholangiopancreatoscopy has played a minor role in the diagnosis and treatment of pancreaticobiliary disorders, initially because of instrument fragility and suboptimal imaging, and later because of improvements in noninvasive and semi-invasive imaging techniques. Digital scopes provide superior images and hold the promise of increased application and improved durability.

Duodenoscope assisted cholangiopancreatoscopy: a review of clinical applications

Duodenoscope assisted cholangiopancreatoscopy allows direct visualization of the pancreatic duct and bile duct. There are several circumstances where direct ductal visualization might be helpful in clarifying a diagnosis or providing targeted treatment. Duodenoscope assisted cholangiopancreatoscopy is currently employed for a variety of indications including: indeterminate ductal strictures and filling defects, marginal chronic pancreatitis, treatment of large intraductal stones, localization of intraductal papillary mucinous tumors, and localization and treatment of hemobilia. There have however been no randomized controlled trials evaluating the diagnostic or therapeutic functions of duodenoscope assisted cholangiopancreatoscopy. This article reviews recent descriptive studies that attempt to clarify the clinical role of this technology.

Efficacy of peroral pancreatoscopy in the diagnosis of pancreatic diseases

BACKGROUND

The aim of this study was to evaluate the usefulness of peroral pancreatoscopy in the diagnosis of pancreatic diseases.

METHODS

Both 3.7-mm (thin) and 0.8-mm (ultra-thin) diameter fiberoptic pancreatoscopes were used in 115 cases (pancreatic cancer, 35; benign ductal stenosis, 20; intraductal papillary-mucinous tumor, 60).

RESULTS

Observation rates for pancreatic cancer, benign ductal stenosis, and intraductal papillary-mucinous tumor were, respectively, 63%, 80%, and 95%. Tumor vessels and papillary tumor were observed when pancreatic cancer was smaller than 2 cm but not when the tumor was larger than 2 cm. Stenosis without significant mucosal changes was observed in 62% of cases of benign ductal stenosis. Coarse mucosa and friability were observed more frequently in association with pancreatic cancer than benign ductal stenosis. Granular mucosa or papillary tumor could be observed in 74% of cases of intraductal papillary-mucinous tumor. Papillary tumor was observed with increasing frequency in cases of intraductal papillary-mucinous tumor as the degree of malignancy increased.

CONCLUSIONS

Peroral pancreatoscopy with an ultra-thin fiberscope is useful in the diagnosis of minute pancreatic lesions. Peroral pancreatoscopy with a thin fiberscope can provide a definitive diagnosis of intraductal papillary-mucinous tumor including the degree of malignancy.

Endoscopic retrograde cholangiopancreatography in the diagnosis and management of pancreatic diseases

Endoscopic retrograde cholangiopancreatography (ERCP) has been used for diagnosis and treatment of pancreatic diseases for over 20 years. ERCP has been most intensely investigated for acute biliary pancreatitis. Randomized trials have proven that its use will decrease morbidity and have suggested a decrease in mortality for patients with severe gallstone pancreatitis. ERCP is also valuable in detecting and treating main pancreatic duct leaks with transpapillary stenting. Symptomatic pseudocysts, which may be seen in either acute or chronic pancreatitis, can be drained via the papilla or through creation of a cystogastrostomy or cystoduodenostomy with a needle-knife sphincterotome. Endoscopic treatment of patients with recurrent acute pancreatitis presumed due to pancreas divisum and sphincter of Oddi dysfunction remains controversial. Dominant pancreatic strictures or calculi in the setting of chronic pancreatitis may be treated with stenting and removal of calculi to improve abdominal pain. Finally, diagnosis of pancreatic cancer by brush cytology and palliative management of biliary obstruction with various plastic and expandable metal sents have simplified management of this difficult problem.

Pancreatoscopy for the next generation: development of the peroral electronic pancreatoscope system

BACKGROUND

To improve visualization of the pancreatic duct with a pancreatoscope, we have developed the smallest known electronic endoscope, that is, the peroral electronic pancreatoscope.

METHODS

This instrument (2.1 mm, external diameter) was developed with a 50k-pixel interline charge coupled device. A peroral fiberoptic pancreatoscope was used as control, connected to a video converter. The visibility of both systems was studied with a test chart. The model pancreatic duct, the oral mucosa, and the pancreatic ducts of a healthy control subject and patients with chronic pancreatitis were examined with both systems.

RESULTS

The smallest visible interval (with a 5 mm distance between the object and the distal end of the endoscope) was 0.07 mm with the peroral electronic pancreatoscope and 0.2 mm with the peroral fiberoptic pancreatoscope. The electronic instrument produced better images of the model pancreatic duct than the fiberoptic endoscope. A clear image of the small vessels of the oral mucosa was obtained with the electronic but not with the fiberoptic instrument. The fine vessel network of the pancreatic duct was visualized only with the electronic instrument; pancreatic duct stones and rough-surfaced pancreatic duct were shown more precisely with the electronic endoscope.

CONCLUSIONS

The peroral electronic pancreatoscope provides images of the fine detail of the pancreatic duct and will contribute to the diagnosis of pancreatic diseases.