Intraductal carcinoma of the pancreas

Trends in malignant intraductal papillary mucinous neoplasm in US adults from 1990 to 2010: a SEER database analysis

Background: Intraductal papillary mucinous neoplasms (IPMNs) are precancerous lesions with a well-described adenoma-carcinoma sequence. Although the risk of malignant transformation has been well studied, data on trends in long-term survival and important prognostic factors associated with survival in malignant IPMN are lacking.

Methods: The Surveillance, Epidemiology, and End Results (SEER) database was queried to identify patients with confirmed malignant IPMN based upon pathologic diagnosis or radiographic evidence concerning for malignant potential. Median survival and age-adjusted incidence were calculated. Cox proportional hazard regression was used to determine independent mortality factors.

Results: Based upon the SEER database query, 2651 patients were diagnosed with malignant IPMN between 1990 and 2010. The age-adjusted incidence of IPMN in 1990 was 0.361 per 100 000 persons (95% confidence interval [CI]: 0.285–0.451) with a steady decline observed through 2010 (0.135 per 100 000 persons, 95% CI: 0.098–0.186). A total of 564 patients (21.3%) underwent a surgical procedure, though the number of patients who underwent surgery from 1990 to 2010 also decreased (1990–1995, n = 132 to 2006–2010, n = 96, respectively). The overall median survival was 4 months and remained relatively stable from 1990 to 2010. Performance of surgery (HR: 0.45, 95% CI: 0.40–0.53, P < 0.001) was associated with a decreased risk of death.

Conclusion: A significant decrease in the incidence of malignant IPMN was seen from 1990 to 2010. There was also no improvement observed in long-term survival. The small percentage of eligible cases receiving surgical treatment suggests that there is room for further improvement in survival, with increased utilization of surgery.

Current recommendations for surveillance and surgery of intraductal papillary mucinous neoplasms may overlook some patients with cancer

BACKGROUND

The 2012 Sendai Criteria recommend that patients with 3 cm or larger branch duct intraductal papillary mucinous neoplasms (BD-IPMN) without any additional "worrisome features" or "high-risk stigmata" may undergo close observation. Furthermore, endoscopic ultrasound (EUS) is not recommended for BD-IPMN <2 cm. These changes have generated concern among physicians treating patients with pancreatic diseases. The purposes of this study were to (i) apply the new Sendai guidelines to our institution's surgically resected BD-IPMN and (ii) reevaluate cyst size cutoffs in identifying patients with lesions harboring high-grade dysplasia or invasive cancer.

METHODS

We retrospectively reviewed 150 patients at a university medical center with preoperatively diagnosed and pathologically confirmed IPMNs. Sixty-six patients had BD-IPMN. Pathologic grade was dichotomized into low-grade (low or intermediate grade dysplasia) or high-grade/invasive (high-grade dysplasia or invasive cancers). Fisher's exact test, chi-square test, student's t test, linear regression, and receiver operating characteristic (ROC) analyses were performed.

RESULTS

The median BD-IPMN size on imaging was 2.4 cm (interquartile range 1.5-3.0). Fifty-one (77 %) low-grade and 15 (23 %) high-grade/invasive BD-IPMN were identified. ROC analysis demonstrated that cyst size on preoperative imaging is a reasonable predictor of grade with an area under the curve of 0.691. Two-thirds of high-grade/invasive BD-IPMN were <3 cm (n = 10). Compared to a cutoff of 3, 2 cm was associated with higher sensitivity (73.3 vs. 33.3 %) and negative predictive value (83.3 vs. 80 %, NPV) for high-grade/invasive BD-IPMN. Mural nodules on endoscopic ultrasound (EUS) or atypical cells on endoscopic ultrasound-fine needle aspiration (EUS-FNA) were identified in all cysts <2 and only 50 % of those <3 cm. Forty percent of cysts >3 cm were removed based on size alone.

DISCUSSION/CONCLUSIONS

Our results suggest that "larger" size on noninvasive imaging can indicate high-grade/invasive cysts, and EUS-FNA may help identify "smaller" cysts with high-grade/invasive pathology.

Intracholecystic papillary-tubular neoplasms (ICPN) of the gallbladder (neoplastic polyps, adenomas, and papillary neoplasms that are ≥1.0 cm): clinicopathologic and immunohistochemical analysis of 123 cases

The literature on the clinicopathologic characteristics of tumoral intraepithelial neoplasms (neoplastic polyps) of the gallbladder (GB) is fairly limited, due in part to the variability in definition and terminology. Most reported adenomas (pyloric gland type and others) were microscopic and thus regarded as clinically inconsequential, whereas papillary in situ carcinomas have been largely considered a type of invasive adenocarcinoma under the heading of "papillary adenocarcinomas." In this study, 123 GB cases that have a well-defined exophytic preinvasive neoplasm measuring ≥1 cm were analyzed. The patients were predominantly female (F/M=2:1) with a mean age of 61 y and a median tumor size of 2.2 cm. Half of the patients presented with pain, and in the other half the neoplasm was detected incidentally. Other neoplasms, most being gastrointestinal tract malignancies, were present in 22% of cases. Gallstones were identified in only 20% of cases. Radiologically, almost half were diagnosed as "cancer," roughly half with polypoid tumor, and in 10% the lesion was missed. Pathologic findings: (1) The predominant configuration was papillary in 43%, tubulopapillary in 31%, tubular in 26%. (2) Each case was assigned a final lineage type on the basis of the predominant pattern (>75% of the lesion) on morphology, and supported with specific immunohistochemical cell lineage markers. The predominant cell lineage could be identified as biliary in 50% (66% of which were MUC1), gastric foveolar in 16% (all were MUC5AC), gastric pyloric in 20% (92% MUC6), intestinal in 8% (100% CK20; 75% CDX2; 50%, MUC2), and oncocytic in 6% (17% HepPar and 17% MUC6); however, 90% of cases had some amount of secondary or unclassifiable pattern and hybrid immunophenotypes. (3) Of the cases that would have qualified as "pyloric gland adenoma," 21/24 (88%) had at least focal high-grade dysplasia and 18% had associated invasive carcinoma. Conversely, 8 of 47 "papillary adenocarcinoma"-type cases displayed some foci of low-grade dysplasia, and 15/47 (32%) had no identifiable invasion. (4) Overall, 55% of the cases had an associated invasive carcinoma (pancreatobiliary type, 58; others, 10). Factors associated significantly with invasion were the extent of high-grade dysplasia, cell type (biliary or foveolar), and papilla formation. Among systematically analyzed invasive carcinomas, tumoral intraepithelial neoplasia was detected in 6.4% (39/606). (5) The 3-year actuarial survival was 90% for cases without invasion and 60% for those associated with invasion. In contrast, those associated with invasion had a far better clinical outcome compared with pancreatobiliary-type GB carcinomas (3-yr survival, 27%), and this survival advantage persisted even with stage-matched comparison. Death occurred in long-term follow-up even in a few noninvasive cases (4/55; median 73.5 mo) emphasizing the importance of long-term follow-up. In conclusion, tumoral preinvasive neoplasms (≥1 cm) in the GB are analogous to their pancreatic and biliary counterparts (biliary intraductal papillary neoplasms, pancreatic intraductal papillary mucinous neoplasms, and intraductal tubulopapillary neoplasms). They show variable cellular lineages, a spectrum of dysplasia, and a mixture of papillary or tubular growth patterns, often with significant overlap, warranting their classification under 1 unified parallel category, intracholecystic papillary-tubular neoplasm. Intracholecystic papillary-tubular neoplasms are relatively indolent neoplasia with significantly better prognosis compared with pancreatobiliary-type GB carcinomas. In contrast, even seemingly innocuous examples such as those referred to as "pyloric gland adenomas" can progress to carcinoma and be associated with invasion and fatal outcome.

Precursor lesions in pancreatic cancer: morphological and molecular pathology

Pancreatic cancer has a dismal prognosis and is the fourth most common cause of cancer related death in Western societies. In large part this is due to its typically late presentation, usually as locally advanced or metastatic disease. Identification of the non-invasive precursor lesions to pancreatic cancer raises the possibility of surgical treatment or chemoprevention at an early stage in the evolution of this disease, when more amenable to therapeutic interventions. Precursor lesions to pancreatic ductal adenocarcinoma, in particular pancreatic intraepithelial neoplasia (PanIN), have been recognised under a variety of synonyms for over 50 years. Over the past decade our understanding of the morphology, biological significance and molecular aberrations of these lesions has grown rapidly and there is now a widely accepted progression model integrating the accumulated morphological and molecular observations. Further progress is likely to be accelerated by improved mouse models of pancreatic cancer and by insight into the cancer genome gained by the International Cancer Genome Consortium (ICGC), in which an Australian consortium is leading the pancreatic cancer initiative. This review also outlines the morphological and molecular features of the other two precursors of pancreatic ductal adenocarcinoma, i.e., intraductal papillary mucinous neoplasms and mucinous cystic neoplasms.

Prediction of invasive carcinoma in branch type intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

Patients with branch duct type intraductal papillary mucinous neoplasm (BD-IPMN) without invasion usually show favorable prognosis. However, the prognosis becomes poor when the IPMN lesions give rise to invasive carcinoma cells. In addition, recent studies have revealed that BD-IPMN is frequently complicated by common type pancreatic ductal carcinoma. Thus, the prognosis of BD-IPMN depends on the occurrence of these two types of invasive carcinoma. However, little is known about the risk factors for the development of these invasive carcinomas in BD-IPMN. This study aims to identify the factors which predict the development of invasive carcinoma in BD-IPMN.

METHODS

Invasive pancreatic carcinoma associating with BD-IPMN was classified as invasive IPMN group (invasive carcinoma derived directly from IPMN lesions) and concomitant group (common type of invasive carcinoma concomitant with BD-IPMN). The relation between the incidence of each type of invasive carcinoma in BD-IPMN and the clinicopathological parameters was retrospectively analyzed.

RESULTS

There were 12 patients with invasive IPMN and 7 patients with concomitant cancer in 159 patients with BD-IPMN. Diameter of dilated branch (P < 0.001) or main pancreatic duct (MPD) (P = 0.001), size of mural nodule (P < 0.001), serum CEA level (P < 0.001) and serum CA19-9 level (P < 0.001) were factors associated significantly with invasive IPMN by univariate analysis. Among these factors, mural nodule with size larger than 6.5 mm [odds ratio 14.86 (95% CI 1.37-60.45); P = 0.02] and serum carcinoembryonic antigen (CEA) level over 5 ng/ml [odds ratio 6.91 (95% CI 1.17-54.13); P = 0.03] were found to be the factors independently associated with invasive IPMN. On the other hand, both univariate and multivariate analyses revealed that elevated carbohydrate antigen 19-9 (CA 19-9) levels were associated with the occurrence of concomitant ductal carcinoma in BD-IPMN [odds ratio 10.31 (95% CI 1.77-81.51); P = 0.01].

CONCLUSIONS

Our results suggested that careful imaging study of the entire pancreas in addition to tumor lesions and measurement of serum CEA and CA19-9 would be required to find out the development of the two types of invasive carcinoma in BD-IPMN.

A population-based, descriptive analysis of malignant intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMN) are distinct precursor lesions that can progress to pancreatic adenocarcinoma; thus, it has been of particular interest to cancer prevention researchers. We set out to do a population-based analysis of malignant IPMNs compared with other pancreatic subtypes to better delineate its characteristics and explore implications for prevention and management.

METHODS

We conducted a case-only analysis of California Cancer Registry data (2000-2007), including descriptive analysis of relevant clinical variables. Overall survival univariate analyses were conducted using the Kaplan-Meier method. Multivariate survival analyses were done using Cox proportional hazards ratios.

RESULTS

Overall, 15,296 pancreatic cancer cases were identified, including incident cases of 10,186 adenocarcinomas, 880 mucinous tumors, 568 endocrine tumors, 3,619 carcinoma not otherwise specified tumors, and 43 malignant IPMNs. Thirty-three (80.5%) IPMN cases had localized disease at presentation, eight had regional disease (19.5%), and no IPMNs were identified with distant disease (two were unstaged). Five-year overall survival was better for malignant IPMN cases (65%) compared with pancreatic endocrine tumors (30%), mucinous tumors (5%), carcinoma not otherwise specified (2%), and adenocarcinoma cases (2%). Compared with adenocarcinoma cases, malignant IPMN cases (hazard ratio = 0.19; 95% CI, 0.10-0.35), endocrine tumors (hazard ratio=0.28; 95% CI, 0.25-0.32), and mucinous tumors (hazard ratio=0.84; 95% CI, 0.77-0.90) had higher overall survival in a multivariate survival analysis after adjustment for age, gender, stage, race, socioeconomic status, surgery, chemotherapy, and radiation therapy.

CONCLUSIONS

Pancreatic malignant IPMNs represent an uncommon pancreatic tumor subtype, uniquely characterized by early stage at presentation and better survival.

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.

Precursors to pancreatic cancer

Infiltrating ductal adenocarcinoma of the pancreas is believed to arise from morphologically distinct noninvasive precursor lesions. These precursors include the intraductal papillary mucinous neoplasm, the mucinous cystic neoplasm, and pancreatic intraepithelial neoplasia. Intraductal papillary mucinous neoplasms are grossly visible mucin-producing epithelial neoplasms that arise in the main pancreatic duct or one of its branches. The cysts of mucinous cystic neoplasms do not communicate with the major pancreatic ducts, and these neoplasms are characterized by a distinct ovarian-type stroma. Pancreatic intraepithelial neoplasia is a microscopic lesion. This article focuses on the clinical significance of these three important precursor lesions, with emphasis on their clinical manifestations, detection, and treatment.

Clinical importance of precursor lesions in the pancreas

Three distinct noninvasive precursor lesions to invasive ductal adenocarcinoma of the pancreas have been described. These include the mucinous cystic neoplasm, intraductal papillary mucinous neoplasm, and pancreatic intraepithelial neoplasia. The early detection and treatment of these lesions can interrupt the progression of a curable noninvasive precursor to an almost uniformly deadly invasive cancer.

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 neoplasms of the pancreas: an analysis of protein expression and clinical features

BACKGROUND/PURPOSE

The molecular pathology of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas has not been well characterized, and there are no reliable markers to predict the presence of associated invasive carcinoma in patients with IPMNs. We investigated the clinicopathologic characteristics of 37 IPMNs and the immunohistochemical findings of these tumors to investigate the malignancy of IPMNs.

METHODS

Between May 1992 and September 2003, 37 patients with IPMNs, 24 with adenoma and 13 with carcinoma, underwent pancreatic resections at Sapporo Medical University Hospital, Japan. In tumor specimens from these patients, we immunohistochemically analyzed the expression of p53 protein, proliferating-cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), matrix metalloproteinase-7 (MMP-7), and E-cadherin. Clinical features and follow-up after resection were recorded.

RESULTS

Aberrant expression of the proteins examined was frequently observed. Namely, there were significant differences in the expression of MMP-7 according to clinicopathological characteristics. Positive expression of MMP-7 was found in all of nine patients with infiltrating ductal pancreatic adenocarcinoma (IDC) and in all of seven patients with invasive intraductal papillary mucinous adenocarcinoma (IC-IPMC); however, 33.3% of patients with noninvasive IPMA, 58.3% of patients with intraductal papillary mucinous adenoma (IPMA), and all normal pancreatic tissues were negative for MMP-7; differences which were statistically significant (P < 0.05).

CONCLUSIONS

Our current results indicate that MMP-7 may play a significant role in the progression of noninvasive to invasive IPMC.

[Intraductal papillary mucinous tumors of the pancreas]

Reports of intraductal papillary mucinous tumors of the pancreas have become substantially more frequent in the literature in the past several years. This increased prevalence is due, among other things, to improved screening techniques, especially high-resolution spatial imaging. These tumors are characterized by proliferation of the intraductal epithelium, mucin production, and ductal dilatation. They grow slowly. Their potential for malignancy is high (although the precise risk remains difficult to assess), but their prognosis, when identified during the first stage of neoplastic transformation (before invasion), is far better than that of 'pancreatic ductal adenocarcinoma. Early diagnosis allows patients to be treated before carcinomatous degeneration. Specific diagnosis makes it possible to define an appropriate treatment strategy - either surgery or monitoring, especially when only the intralobular ducts are affected. In that case, the risk of malignant degeneration is much lower than with lesions in the pancreatic duct or in combined forms.

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.

A resected case of multiple intraductal papillary mucinous tumors of the pancreas with US-guided ductal branch-oriented partial pancreatectomy

A 69-year-old man with epigastralgia was admitted on August 26, 2002 and diagnosed with multiple intraductal papillary mucinous tumors by various imagings. The cystic tumor of pancreas head had a diameter of 2 cm, and the mural nodule of the cystic tumor measured only 3 mm. In the pancreas body the cystic tumor was measured at 1.5 cm with the mural nodule of the cystic tumor measuring 3 mm. It was believed that the tumors were benign. However, a mural nodule of the cystic lesion was recognized, thus, the possibility of malignancy could not be completely ruled out. The reduction operation for preservation of pancreatic parenchyma should be selected for these circumstances. Ductal branch-oriented partial pancreatectomy was performed on September 6, 2002 with intraoperative ultrasonography and a Cavitron Ultrasonic Aspirator, preserving the main pancreatic duct and normal pancreatic parenchyma. The operation was successful, and the histopathological diagnosis of the tumors was intraductal papillary adenoma of the pancreas.

Precursors to invasive pancreatic cancer

Pancreatic cancer, once invasive, is almost uniformly fatal. In order to alleviate the dismal prognosis associated with this disease, it is imperative that pancreatic cancer be recognized and treated prior to invasion. Understanding the morphology and biology of precursor lesions of invasive pancreatic cancer has therefore become an issue of paramount importance. In the last decade, significant progress has been in the recognition and appropriate classification of these precursor lesions, and the current review will focus on our state-of-the-art knowledge on this topic. Mucinous cystic neoplasms (MCNs), intraductal papillary mucinous neoplasms (IPMNs), and pancreatic intraepithelial neoplasia (PanIN) encompass the three known morphologically distinct precursors to invasive pancreatic cancer. In addition to discussion of the "classic" precursor entities, this review will also address some of the recent diagnostic controversies for these lesions, in particular features that distinguish IPMNs from PanIN lesions. Finally, the potential clinical impact of recognizing these precursor lesions in the context of early detection of pancreatic cancer will be discussed.

An illustrated consensus on the classification of pancreatic intraepithelial neoplasia and intraductal papillary mucinous neoplasms

Invasive pancreatic ductal adenocarcinoma is an almost uniformly fatal disease. Several distinct noninvasive precursor lesions can give rise to invasive adenocarcinoma of the pancreas, and the prevention, detection, and treatment of these noninvasive lesions offers the potential to cure early pancreatic cancers. Noninvasive precursors of invasive ductal adenocarcinoma of the pancreas include pancreatic intraepithelial neoplasias (PanINs), intraductal papillary mucinous neoplasms (IPMNs), and mucinous cystic neoplasms. Diagnostic criteria, including a distinct ovarian-type stroma, and a consistent nomenclature are well established for mucinous cystic neoplasms. By contrast, consistent nomenclatures and diagnostic criteria have been more difficult to establish for PanINs and IPMNs. Because both PanINs and IPMNs consist of intraductal neoplastic proliferations of columnar, mucin-containing cells with a variable degree of papilla formation, the distinction between these two classes of precursor lesions remains problematic. Thus, considerable ambiguities still exist in the classification of noninvasive neoplasms in the pancreatic ducts. A meeting of international experts on precursor lesions of pancreatic cancer was held at The Johns Hopkins Hospital from August 18 to 19, 2003. The purpose of this meeting was to define an international acceptable set of diagnostic criteria for PanINs and IPMNs and to address a number of ambiguities that exist in the previously reported classification systems for these neoplasms. We present a consensus classification of the precursor lesions in the pancreatic ducts, PanINs and IPMNs.

Intraductal papillary mucinous neoplasms of the pancreas: an analysis of clinicopathologic features and outcome

OBJECTIVE

To define the natural history of resected intraductal papillary mucinous neoplasms (IPMN) of the pancreas and to identify clinical and pathologic prognostic features.

SUMMARY BACKGROUND DATA

IPMN of the pancreas is a recently described pancreatic tumor. Because of a limited number of cases, prognostic factors and the natural history of resected cases have not been well defined.

MATERIALS AND METHODS

A prospective pancreatic database was reviewed to identify patients with IPMN who were surgically managed. Pathologic re-review of each case was performed, and the clinicopathologic features were examined. Log rank and chi2 analysis were used to identify factors predictive of survival and recurrence.

RESULTS

Over a 17-year period, 63 patients were identified. One patient was unresectable, 6 (10%) underwent a total pancreatectomy, and 56 (89%) had a partial pancreatectomy. Invasive carcinoma was present in 30 patients (48%). Transection margins were involved with atypia or carcinoma in 32 patients (51%). The median follow-up for survivors was 38 months. Disease-specific 5- and 10-year survival were 75% and 60%, respectively. Significant predictors of poor outcome included presentation with elevated bilirubin, presence of invasive carcinoma, increasing size and percentage of invasive carcinoma, histologic type of invasive carcinoma, positive lymph nodes, and vascular invasion. The presence of atypia or carcinoma in situ at the ductal resection margin was not associated with a poor outcome.

CONCLUSIONS

Overall, IPMN has a favorable prognosis. Poor outcome in a subset of patients is largely the result of the presence, extent, and type of an invasive component, lymph node metastases, and vascular invasion.

Intraductal papillary mucinous neoplasm of the pancreas: diagnosis and treatment

Intraductal papillary mucinous neoplasm (IPMN) is characterized by cystic dilatation of the main and/or branch pancreatic duct. Only one-third of all patients are symptomatic, and others are diagnosed by chance. IPMNs are classified into 3 types: main duct, branch duct, and mixed IPMN. Most branch-type IPMNs are benign, while the other 2 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, at the very least, the existence of adenoma. Ultrasonography, endosonography, and intraductal ultrasonography clearly demonstrate ductal dilatation and mural nodules, and magnetic resonance pancreatography best visualizes the entire outline of IPMN. Not infrequently, synchronous or metachronous malignancy develops in various organs, including the pancreas. Prognosis is excellent after complete resection of benign and noninvasive malignant IPMNs. Asymptomatic branch-type IPMNs without mural nodules may be followed up without resection. Malignant IPMNs displaying acquired aggressiveness after parenchymal invasion require adequate lymph node dissection. Total pancreatectomy is needed for some IPMNs; its benefits, however, must be balanced against operative and postoperative risks because most IPMNs are slow growing and affect elderly people, and prognosis is favorable for IPMN patients with even malignant neoplasms.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Intraductal papillary-mucinous tumor of the pancreas concomitant with ductal carcinoma of the pancreas

BACKGROUND

Despite the recent progress of diagnostic and therapeutic modalities, the clinical course of patients with ductal carcinoma (DC) of the pancreas remains dismal. Intraductal papillary-mucinous tumor of the pancreas (IPMT) is sometimes accompanied by malignant diseases of the other organs and pancreatic adenocarcinoma. Thus, IPMT may be a potential diagnostic clue to DC of the pancreas at early phase.

METHODS

Clinicopathologic findings of 7 Japanese patients with IPMT of the pancreas concomitant with independent DC were examined and compared with those of 69 patients with IPMT alone and of 70 with DC alone.

RESULTS

The seven patients corresponded to 9.2% of 76 patients with IPMT and 9.1% of 77 patients with DC. The seven male patients ranged from 55 to 75 years with a mean of 64.3. DC was synchronous with IPMT in five patients, metachronous to IPMT (4 years after IPMT) in one, and synchronous with IPMT and metachronous to IPMT and DC (7 years after IPMT) in the other. In 4 patients, the presence of IPMT led to the diagnosis of DC. All the 7 IPMTs were of branch type with a mean diameter of 3.0 cm. The IPMT was located in the head of the pancreas in 3, body in 2 and tail in the other 2. All the 7 IPMTs were adenoma with mild dysplasia. Two of the 7 patients with DC had in situ carcinoma, 1 minimally invasive carcinoma and the remaining 4 invasive carcinoma. The mean diameter of seven DCs (3.0 cm) with IPMT were smaller than that of 70 DCs (3.6 cm) (8P = 0.0295). Stage (stage I/II/III/IV = 3/0/3/1) of the seven DCs concomitant with IPMT were significantly earlier than that (stage I/II/III/IV = 5/6/28/31) of the other 70 (p = 0.0203). The survival curve of the 7 patients with IPMT and DC was significantly better than that of the 70 with DC alone (p = 0.0460).

CONCLUSIONS

Clinicians should pay attention to the possible presence of DC of the pancreas in male patients with intraductal papillary-mucinous adenoma of the pancreas of branch type in their 6th to 8th decades.

DNA ploidy and markovian analysis of neoplastic progression in experimental pancreatic cancer

Computer-assisted analysis of DNA ploidy and nuclear morphology were used to elucidate changes in the cell nucleus that occur during the development of experimental pancreatic cancer. Ductal pancreatic adenocarcinoma was induced in 49 Syrian hamsters by SC injection of N-nitrosobis (2-oxopropyl) amine; twenty hamsters served as controls. Groups of animals were sacrificed every 4 weeks for 20 weeks and adjacent sections of pancreatic tissue were H&E and Feulgen-stained for light microscopy and computer assisted cytometry. Pancreatic ductal cells were classified as normal, atypical, or malignant; tissue inflammation (pancreatitis) was also noted when present. DNA ploidy and nuclear morphology evaluation (Markovian analysis) identified an atypical cell stage clearly distinguishable from either normal or malignant cells; pancreatitis preceded this atypia. The DNA ploidy histogram of these atypical cells revealed a major diploid peak and a minor aneuploid peak. The receiver operator characteristic curve areas for a logistic regression model of normal vs atypical cells was 0.94 and for atypical vs malignant was 0.98, numbers indicative of near-perfect discrimination among these three cell types. The ability to identify an atypical cell population should be useful in establishing the role of these cells in the progression of human pancreatic adenocarcinoma.

Magnetic resonance cholangiopancreatography for postoperative follow-up of intraductal papillary-mucinous tumors of the pancreas

BACKGROUND

After resection of an intraductal papillary-mucinous tumor (IPMT), benign tumors or portions of the resected tumor are sometimes left in place to avoid total pancreatectomy. We evaluated the role of magnetic resonance cholangiopancreatography (MRCP) in postoperative follow-up.

METHODS

Twenty-two patients underwent MRCP 0.5 to 6.5 years after pancreatic resection for IPMT.

RESULTS

Two patients with surgical margin involvement of the main pancreatic duct showed mildly enhanced ductal dilatation due to anastomotic stenosis. In 4 patients with residual IPMT of the branch ducts, postoperative MRCP demonstrated no changes. MRCP revealed new IPMT 1 year after surgery in 1 patient. No patients showed intraductal or intracystic mural nodules postoperatively. In 3 patients with postoperative pancreatitis or recurrent abdominal discomfort, MRCP demonstrated ductal dilatation and poor secretin-stimulated pancreatic secretion into the gastrointestinal tract, which suggested pancreatoenterostomic stenosis.

CONCLUSIONS

MRCP is useful for postoperative follow-up of IPMT, in terms of investigating residual or recurrent IPMT and evaluating postpancreatectomy long-term complications.

Early pancreatic cancer

The results of surgical treatment for ordinary carcinoma of the pancreas, even now considered the only means for cure, have been dismal. In order to define early pancreatic cancer, aiming amelioration of surgical results, early pancreatic cancer has been seeked. It may be readily conceivable that the smaller the tumor size, the earlier the lesion. The relationship between tumor size and surgical results was reviewed from the literature, some of which included articles written in Japanese. Tumor size < or = 2 cm in diameter is not always an early cancer. Tumor < 1 cm could be an early cancer but does not definitely reveal long-term survival. An increase of pancreatic cancer in Japan may be strongly related with the increased elderly population. Small cystic lesions which develop in elderly persons seem to indicate carcinogenesis of ordinary ductal cancer of the pancreas. Carcinoma in situ may be an early pancreatic cancer. Early pancreatic cancer is defined as an intraductal adenocarcinoma without any invasion or with minimal invasion to the stroma, regardless of size or extent of the lesion.

Intraductal papillary mucinous tumors of the pancreas: features with multimodality imaging

The radiologic diagnosis of intraductal papillary mucinous tumor (IPMT) of the pancreas is important to establish because of its malignant potential and in order to determine the site of tumor origin and its extent. These pancreatic tumors are recognized more often now than previously because of the increasing use of imaging modalities such as computed tomography and magnetic resonance cholangiopancreatography. The main features of IPMT are given in this pictorial essay, with illustrations provided from a series of 50 patients with a surgically proven diagnosis of IPMT.

Intraductal papillary-mucinous tumors of the pancreas: differential diagnosis between benign and malignant tumors by endoscopic ultrasonography

OBJECTIVES

Recently, intraductal papillary-mucinous tumor (IPMT) of the pancreas has increasingly been recognized. However, differential diagnosis between benign and malignant IPMT is often difficult using conventional imaging modalities. The purpose of this study was to retrospectively investigate the value of endoscopic ultrasonography (EUS) for differentiating malignant from benign IPMT.

METHODS

A total of 51 patients with IPMT were preoperatively examined by EUS. The endosonograhic findings were compared with histopathological findings of the resected specimens.

RESULTS

In main duct type IPMT, the diameter of the main pancreatic duct (MPD) was > or =10 mm in seven of the eight malignant tumors, compared with two of the seven benign tumors (p < 0.05). In branch duct type IPMT, three of the four large tumors (>40 mm) with irregular thick septa were malignant lesions. In both main duct type IPMT and branch duct IPMT, eight patients had large mural nodules (>10 mm); seven of the eight tumors were malignant and one of the eight tumors was benign. When the tumor was diagnosed as malignant according to above three findings, EUS was able to differentiate between malignant and benign IPMT with an accuracy of 86%.

CONCLUSIONS

Main duct type tumors with > or =10 mm dilated MPD, branch duct type tumors (>40 mm) with irregular septa, and large mural nodules (>10 mm) strongly suggest malignancy on EUS. EUS would be a useful modality for differentiating between benign and malignant IPMT.

Total pancreatectomy in six patients with intraductal papillary mucinous tumour of the pancreas: the treatment of choice

BACKGROUND

Intraductal papillary mucinous tumours (IPMT) were described as a distinct entity in 1982.The extent of surgical resection remains controversial.

METHODS

Six patients with a diffuse dilatation of the main pancreatic duct were treated with total pancreatectomy for cure of IPMT.

RESULTS

Histological examination showed one IPM adenoma, four IPM non-invasive carcinomas and one IPM invasive carcinoma. In all but one case multifocal extensive intraductal changes were found, affecting either most of the pancreas or the whole organ. All patients survived the operation and remain alive 5-56 months later. Post-pancreatectomy diabetes has been moderately well controlled.

DISCUSSION

IPMTs represent a subgroup of pancreatic neoplasms with a favourable prognosis, and the resection should aim at removing all dysplastic foci. In cases with diffuse dilatation of the main pancreatic duct, widespread tumour involvement of the duct system can be expected, so total pancreatectomy should be the operation of choice.

Peroral pancreatoscopy in the diagnosis of mucin-producing tumors of the pancreas

BACKGROUND

Mucin-producing tumor of the pancreas is an increasingly recognized clinical entity. However, the differentiation of benign from malignant mucin-producing tumors of the pancreas is challenging. Peroral pancreatoscopy as recently developed may have potential for the diagnosis of mucin-producing tumors of the pancreas.

METHODS

The subjects were 41 patients with clinically diagnosed mucin-producing tumors of the pancreas, 40 of whom underwent surgical resection. Autopsy findings were available in another patient with unresectable disease. Histologically, hyperplasia was identified in 3 patients, mildly atypical adenoma in 11, severely atypical adenoma in 16, and adenocarcinoma in 11. Peroral pancreatoscopy was performed before surgery or pathologic examination. The findings were retrospectively evaluated and compared with the histopathologic diagnosis.

RESULTS

Pancreatoscopic observation was successful in 30 patients (73.2%). Elevated lesions were identified in 22 (73.3%). Villous or vegetative elevations and red color markings were frequently found in severely atypical adenoma or adenocarcinoma. Tumor location (main or branch duct type) did not correlate with survival after resection. Partial resection was performed in 7 of 30 patients with nonmalignant tumors and resulted in favorable outcomes.

CONCLUSION

Peroral pancreatoscopy can be used to differentiate benign mucin-producing tumors of the pancreas (hyperplasia and mildly atypical adenoma) from the more dysplastic lesions (severely atypical adenoma and adenocarcinoma) and may provide useful information for determining the type of surgery to be performed.

Intraductal papillary mucinous tumors of the pancreas. Verona University Pancreatic Team

METHODS

Literature is thoroughly reviewed and compared to our own experience.

RESULTS

Clinical history data do not appear to be useful in differentiating between benign and malignant cases. Usually IPMT patients are older than individuals suffering from chronic obstructive pancreatitis and tend to drink and smoke less. Malignant forms of IPMT are more frequently associated with diabetes, and pain seems to be more frequent in benign cases, although these findings are not confirmed in all reports. Also, laboratory tests are of little use, whereas imaging findings currently enable us to reach a correct diagnosis in about 70% of cases without differentiating in a reliable and definitive way the benign or malignant nature of the neoplasm. The WHO classification appears to be related to the different prognosis. Surgery, whenever possible, is the gold standard treatment.

CONCLUSION

IPMT are a recent established clinical entity embracing a spectrum of lesions ranging from benign to malignant infiltrating cases. The only recognized radical treatment is surgery. Despite diagnostic capacity based on clinical presentation and imaging techniques has becoming increasingly refined we are still incapable of identifying the different degree of malignancy preoperatively, if any. The lengthy mean survival after resection confirm the high potential cure rate of IPMT of the pancreas.

Extrapancreatic neoplasms occur with unusual frequency in patients with intraductal papillary mucinous tumors of the pancreas

OBJECTIVE

Intraductal papillary mucinous tumor (IPMT) of the pancreas has a favorable prognosis. Non-pancreatic primary neoplasms have potential prognostic significance in patients with IPMT. This study focused on the incidence and characteristics of nonpancreatic neoplasms in IPMT patients.

METHODS

Forty-two patients (mean age, 64 yr) with IPMT underwent surgery; 16 had adenoma and 26 adenocarcinoma. Preoperative and postoperative, nonpancreatic neoplasms were investigated. The mean postoperative follow-up period was 4.2 yr (range, 0.2-13 yr). Furthermore, 46 patients with pancreatic ductal adenocarcinoma were analyzed for nonpancreatic neoplasms.

RESULTS

Five-year survival rates were 100% for benign and 82% for malignant IPMT. Twenty patients (48%) had nonpancreatic neoplasms, before (n = 11), at (n = 4), and after (n = 10) surgery for IPMT. Fifteen patients (32%) had nonpancreatic malignancies. Nonpancreatic neoplasms included colorectal adenomas (21%) and adenocarcinomas (12%), and gastric carcinomas (10%). One patient died of subsequent bile duct carcinoma. Development of nonpancreatic neoplasms was related to age but not to gender, family history, adjuvant chemotherapy, or IPMT pathology. The incidences of nonpancreatic neoplasms and malignancies were significantly higher in patients with IPMT than in those with pancreatic ductal adenocarcinoma (11% and 7%, respectively).

CONCLUSIONS

IPMT is associated with a high incidence of nonpancreatic neoplasms, particularly colorectal neoplasms. In IPMT patients, systemic surveillance may allow early detection of second tumors. In preoperative screening and postoperative follow-up of patients with nonpancreatic neoplasms, the possibility of IPMT should be considered.

Intraductal carcinoma (carcinoma in situ) of the pancreas with microinvasion

We report a case of predominantly intraductal carcinoma of the pancreas with microscopic foci of invasive carcinoma in a patient with chronic pancreatitis. In this article, we discuss the pathologic and prognostic features of pancreatic carcinoma in situ. This entity is probably overlooked due to a number of reasons, including the fact that, in most cases, pancreatic ductal carcinomas are extensively infiltrative at the time of surgical removal; the atypical epithelial changes in the intraductal carcinoma had been overlooked in the presence or absence of an invasive component; epithelial changes may be missed due to insufficient sampling; and last, the differentiation with atypical epithelial hyperplasia is a subjective matter. Intraductal carcinoma of the pancreas is a distinct pathological entity with characteristic morphologic changes restricted to the ductal epithelium, bearing important prognostic implications.

Intraductal papillary mucinous tumors of the pancreas: imaging studies and treatment strategies

OBJECTIVE

We analyzed clinicopathologic and imaging features and the prognosis of intraductal papillary mucinous tumor (IPMT) of the pancreas to identify imaging findings indicative of malignancy and to establish the optimal treatment strategy.

SUMMARY BACKGROUND DATA

In IPMT, preoperative differentiation between adenoma and adenocarcinoma is often difficult. Appropriate treatment based on pathologic study and surgical outcome has not been adequately documented.

METHODS

Forty-one patients with IPMT underwent surgery; 15 with adenoma and 26 with adenocarcinoma; main duct type in 13, combined type in 12, and branch duct type in 16.

RESULTS

In malignant IPMT, deep invasion was found in 62% and lymph node metastasis in 23% (peripancreatic nodes in 19% and distant nodes in 4%). Tumors with mural nodules (86%) had a significantly higher incidence of carcinoma than tumors without nodules (37%). IPMT with a main pancreatic duct > or =15 mm or tumor diameter > or =30 mm (branch duct type) showed a high prevalence of adenocarcinoma. Main duct (54%) and combined (58%) type tumor, and tumors with mural nodules (64%) often showed invasion. All five branch duct tumors less than 30 mm without nodules were adenomas. However, imaging studies could not definitely distinguish adenocarcinomas from adenomas. Complete resection was possible for all adenomas and 88% of adenocarcinomas. Five-year survival rates for patients with adenomas and adenocarcinomas were 100% and 82%, respectively.

CONCLUSIONS

IPMT has a favorable prognosis, regardless of deep invasion or node metastasis. IPMT requires peripancreatic node dissection in addition to complete tumor excision. Node dissection may be omitted for branch duct tumors less than 30 mm without mural nodules.

Intraductal papillary tumors of the pancreas: evaluation with endoscopic ultrasonography

BACKGROUND

We retrospectively analyzed the endoscopic ultrasonographic characteristics of intraductal papillary tumors of the pancreas and identified signs indicative of malignant tumors.

METHODS

Twenty-eight patients with intraductal tumors and 38 with other pancreatic cystic lesions underwent endoscopic ultrasonography, conventional ultrasonography, and endoscopic retrograde cholangiopancreatography (ERCP).

RESULTS

Intraductal tumors were classified into three subtypes, and endoscopic ultrasonographic characteristics were assessed. In main duct type tumors, the main pancreatic duct showed a segmental or diffuse moderate-to-marked dilatation, often associated with intraductal nodules. Pancreatic parenchymal atrophy was frequently recognized. Branch duct type tumors consisted of multiple 5 to 20 mm cysts with the appearance of a cluster of grapes. The main duct was mildly dilated or nondilated. Combined type tumors had features of both main duct and branch duct types. Endoscopic ultrasonography (92%) differentiated pancreatic cystic lesions more precisely than ultrasonography (82%) and ERCP (89%). Main duct or combined type tumors, large tumors (> or = 30 mm for branch duct type), marked dilatation of the main pancreatic duct (> or = 10 mm for other types), and mural nodules suggested malignancy. Endoscopic ultrasonography demonstrated these signs more accurately than ultrasonography or ERCP.

CONCLUSION

Endoscopic ultrasonography is useful for diagnosing intraductal papillary tumors, particularly for predicting malignancy.

Infiltrating carcinoma arising in intraductal papillary-mucinous tumor of the pancreas

A case of an infiltrating carcinoma arising in an intraductal papillary mucinous tumor (IPMT) of the pancreas was reported in a 60-yr-old man. Preoperative diagnosis of the carcinoma was established on the basis of fine-needle aspiration biopsy.

Intraductal papillary tumors of the pancreas: evaluation with magnetic resonance cholangiopancreatography

OBJECTIVE

We analyzed the findings of intraductal papillary tumors of the pancreas by magnetic resonance cholangiopancreatography (MRCP).

METHODS

Twelve patients with intraductal papillary tumors (main duct type, n = 3; branch duct type, n = 8; combined type, n = 1) underwent endoscopic retrograde cholangiopancreatography (ERCP) (n = 11) and MRCP, using half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences (n = 12). Imaging findings were compared with operative and pathological findings in all the patients.

RESULTS

Although ERCP failed to fully depict the main pancreatic duct and cystic tumors in six of 11 patients because of copious intraductal mucin, MRCP provided complete images of these structures in all 12 patients. In main duct type tumors, MRCP demonstrated moderate-marked, diffuse dilation of the main pancreatic duct. Branch duct type tumors showed "grape-like" clusters of cysts with no or only mild, diffuse dilation of the main duct. In combined type tumors, MRCP demonstrated a markedly dilated main duct with a large unilocular cyst of the collateral duct. MRCP detected more mural nodules (75%, three of four patients) than ERCP (25%, one of four). MRCP allowed more precise diagnosis of the type, size, and extent of tumors than ERCP, as confirmed by pathologic findings.

CONCLUSION

MRCP demonstrates intraductal papillary tumors less invasively and more completely than ERCP.

Two types of mucin-producing cystic tumors of the pancreas: diagnosis and treatment

BACKGROUND

This study focuses on clinicopathologic, imaging, and prognostic differences between two types of mucin-producing cystic tumors of the pancreas, with the aim of appropriate management of these tumors.

METHODS

Forty-six patients with mucin-producing cystic tumors underwent operation. The types of tumors were as follows: mucinous cystic neoplasm, adenoma (6) and adenocarcinoma (12); intraductal papillary tumor, adenoma (10) and adenocarcinoma (18).

RESULTS

Gender, age, symptoms, signs, tumor location and size, and the presence or absence of communication with the pancreatic duct differed between the two types. Mucinous cystadenocarcinomas showed deep invasion more often than intraductal papillary adenocarcinomas. Lymph node involvement was seen in 58% of mucinous cystadenocarcinomas but in only 22% of intraductal papillary adenocarcinomas. Tumors with mural nodules tended to show deep invasion and nodal metastasis. All four intraductal papillary tumors smaller than 3 cm without mural nodules were adenomas. Imaging studies allowed accurate differentiation between the two types but not between adenomas and adenocarcinomas. Five-year survival rates for patients with adenomas, mucinous cystadenocarcinomas, and intraductal papillary adenocarcinomas were 100%, 33%, and 81%, respectively.

CONCLUSIONS

Mucinous cystic neoplasm necessitates complete tumor excision with wide dissection of lymph nodes including paraaortic nodes. Intraductal papillary tumor requires only peripancreatic node dissection; for tumors smaller than 3 cm without mural nodules, node dissection may be unnecessary.

Pancreatic mucinous ductal ectasia and intraductal papillary neoplasms. A single malignant clinicopathologic entity

OBJECTIVE

The purpose of the study is to review a single institutional experience with mucinous ductal ectasia (MDE) and intraductal papillary neoplasms (IPNs) and to compare the clinicopathologic features of the two groups of tumors.

SUMMARY BACKGROUND DATA

Mucinous ductal ectasia and IPNs represent newly recognized categories of pancreatic exocrine tumors, previously confused with pancreatic cystic neoplasms. The natural history of MDE and IPN is not well understood, and it is unclear whether MDE and IPN represent two distinct tumors or the same clinicopathologic entity.

METHODS

The authors reviewed the clinical presentation, treatment, histopathology, and outcomes of 23 patients diagnosed with MDE or IPN at their institution over the past 6 years.

RESULTS

The mean age at presentation for the cohort of patients with MDE and IPN was 62.5 years. The prevalence of abdominal pain was 75%, jaundice 25%, weight loss 42%, steatorrhea 37.5%, diabetes 37.5%, and history of pencreatitis 29%. Serum CA 19-9 levels ranged from 0 to 5350 units/mL with high levels reflecting advanced disease. There were no significant differences between MDE and IPN with respect to these parameters. Both MDE and IPN comprised papillary villous epithelial neoplasms involving the main and large pancreatic ducts. The tumors ranged from a few millimeters in size to panductal and were distinguished easily from cystic neoplasms in all cases. Invasive carcinoma was present in 11 (46%) of 24 patients, carcinoma in situ in an additional 10 (42%) of 24 patients, and low grade dysplasia in the remaining 3 (12%) of 24 patients. Mucinous ductal ectasia and IPN differed histopathologically only in degree of mucin secretion and tumor location. Mucinous ductal ectasia, but not IPN, was characteristically mucin-hypersecreting and more frequently involved the head of the gland than did IPN (11/16 vs. 1/8 p < 0.04). All patients were explored surgically and 20 (83%) of 24 of the tumors were resectable with frozen section control of the duct margins (9 pancreatoduodenectomies, 4 distal pencreatectomies, 7 total pancreatectomies). Despite the 88% prevalence of cancer, the overall survival at a mean follow-up of 21 months was 13 (87%) of 15 for MDE and 5 (71%) of 7 for IPN.

CONCLUSIONS

Intraductal papillary neoplasms with or without MDE represent a spectrum of main duct papillary tumors ranging from adenoma to carcinoma with differing amounts of extracellular mucin production. Malignant IPNs with or without MDE typically exhibit extensive intraductal growth but are slow to invade the periductal tissues and slow to metastasize. The majority of patients with these tumors have resectable disease and a favorable prognosis; endoscopic therapy is inappropriate. The encompessing term intraductal papillary-mucinous tumors is appropriate.

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

BACKGROUND

Most pancreatic carcinomas are unresectable at the time of diagnosis, but recently the diagnosis of carcinoma in situ of the pancreas has become possible. This diagnosis can be made by the detection of cancer cells in pancreatic juice and the radiographically demonstrated lack of a mass lesion. It has greatly improved the effectiveness of surgery. Carcinoma in situ remains within the pancreatic ductal epithelium and has not yet invaded the parenchyma. However, it has often been difficult to locate carcinoma in situ by conventional diagnostic methods, such as ultrasonography, endoscopic ultrasonography, computed tomography, and endoscopic retrograde pancreatography.

METHODS

Peroral pancreatoscopy and a new method of cytodiagnosis, pancreatoscopic cytology, were used to analyze 11 patients with carcinoma in situ of the pancreas, 10 with disease in the main duct of the pancreas and 1 with disease in the branch ducts. The results of pancreatoscopic cytology were compared with those of conventional pancreatic juice cytology.

RESULTS

Under peroral pancreatoscopy, carcinoma in situ of the pancreas in the main duct appeared as papillary mucosa, irregular mucosa, or nodular mucosa. Using pancreatoscopic cytology, cancer cells were obtained from all the lesions, allowing a more thorough analysis than pancreatic juice cytology.

CONCLUSIONS

Peroral pancreatoscopy and pancreatoscopic cytology are useful for locating and diagnosing carcinoma in situ of the pancreas.

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

BACKGROUND

Most pancreatic carcinomas are unresectable at the time of diagnosis, but recently the diagnosis of carcinoma in situ of the pancreas has become possible. This diagnosis can be made by the detection of cancer cells in pancreatic juice and the radiographically demonstrated lack of a mass lesion. It has greatly improved the effectiveness of surgery. Carcinoma in situ remains within the pancreatic ductal epithelium and has not yet invaded the parenchyma. However, it has often been difficult to locate carcinoma in situ by conventional diagnostic methods, such as ultrasonography, endoscopic ultrasonography, computed tomography, and endoscopic retrograde pancreatography.

METHODS

Peroral pancreatoscopy and a new method of cytodiagnosis, pancreatoscopic cytology, were used to analyze 11 patients with carcinoma in situ of the pancreas, 10 with disease in the main duct of the pancreas and 1 with disease in the branch ducts. The results of pancreatoscopic cytology were compared with those of conventional pancreatic juice cytology.

RESULTS

Under peroral pancreatoscopy, carcinoma in situ of the pancreas in the main duct appeared as papillary mucosa, irregular mucosa, or nodular mucosa. Using pancreatoscopic cytology, cancer cells were obtained from all the lesions, allowing a more thorough analysis than pancreatic juice cytology.

CONCLUSIONS

Peroral pancreatoscopy and pancreatoscopic cytology are useful for locating and diagnosing carcinoma in situ of the pancreas.

Intraductal papillary-mucinous neoplasm of the pancreas: a report of five cases with immunohistochemical findings

Five cases of intraductal papillary-mucinous neoplasm (IPMN) of the pancreas are here described. This group of tumors represents a distinct clinicopathological entity with characteristic endoscopic, radiological, gross and microscopic appearances. Our five cases all showed marked dilatation of the main pancreatic duct which contained mucin and papillary tumor, sometimes filling and sometimes lining the lumen. The papillae were lined by columnar epithelium showing varying degrees of dysplasia. In one case there was adjacent invasive adenocarcinoma. Immunohistochemical staining for p53 protein was strongly positive in a majority of cells in the three cases with severe epithelial dysplasia and in the invasive adenocarcinoma, while weaker staining in a minority of cells was seen in the remaining two cases. A small proportion of tumor cells expressed PCNA and Ki-67 immunohistochemically in four cases, while the case with severe dysplasia and invasive carcinoma showed positivity for these proliferation markers in most cells. The four cases of exclusively intraductal tumor showed no evidence of disease recurrence at follow-up (median 55 months). The patient with IPMN and associated invasive adenocarcinoma died 21 months post-operatively. In view of its relatively favourable prognosis, it is important that IPMN is recognised.

Intraductal papillary mucinous tumours of the pancreas. Clinical and therapeutic issues in 32 patients

BACKGROUND/AIM

The clinical presentation, pancreatographic findings, and outcome of patients with intraductal papillary mucinous tumours have not been reported in a large patient series in the English literature. This study reviewed 32 patients diagnosed between 1980 and 1994, with special attention to these features.

PATIENTS/METHOD

Data on 24 operated and eight non-operated patients were abstracted from inpatient, outpatient, and procedure records.

RESULTS

Acute pancreatitis was the most common presentation seen in 56% of patients. Relapses occurred during an average of 43 months before diagnosis. A patulous papilla was observed in 55% of the cases. Endoscopic pancreatography showed communicating cysts, a diffusely dilated main pancreatic duct, and amorphous defects in 42, 71, and 97% respectively. An invasive carcinoma was found in nine of 24 (37.5%) of operated patients: six of the patients (66%) died or developed metastases within three years after surgery. No mortality was related to the tumour in absence of invasive carcinoma. Benign recurrence on the remaining pancreas was unusual and occurred late after surgery.

CONCLUSIONS

Intraductal papillary mucinous tumours must be considered in the differential diagnosis of relapsing pancreatitis. Despite slow growing, these tumours have an obvious malignant potential and a very poor prognosis when invasive carcinoma has developed. Early recognition and resection are the cornerstones of treatment.

Mucin-producing neoplasms of the pancreas. Intraductal papillary and mucinous cystic neoplasms

OBJECTIVE

The authors compared the clinicopathologic features of the intraductal papillary and mucinous cystic neoplasms of the pancreas and clarified the similarities as well as the differences between these two tumors. In addition, they reviewed 104 cases of the intraductal papillary neoplasm in the English literature to provide a global view of the condition.

SUMMARY BACKGROUND DATA

Controversy about the term and clinicopathologic entity still exist regarding intraductal papillary neoplasm of the pancreas. Currently, with only a few cases of this rare tumor in each report, there continues to be inadequate knowledge available regarding the tumor and methods by which to distinguish it from the mucinous cystic neoplasm.

METHODS

Multiple demographic and clinicopathologic parameters were compared between intraductal papillary and mucinous cystic neoplasms identified from 1985 to 1994 in the Medical Center, Veterans General Hospital--Taipei.

RESULTS

There were four intraductal papillary adenocarcinomas and 10 mucinous cystic neoplasms (8 cystadenocarcinoma and 2 cystadenoma). The sex, age, size, tumor location, and pathologic findings were quite different between these two groups. Clinical presentation of intraductal papillary adenocarcinomas were similar to those of periampullary tumors. The most common presentations of mucinous cystic neoplasm were epigastric pain and abdominal mass. All four intraductal papillary adenocarcinoma showed mucin secretion from a patulous orifice of the ampulla of Vater and filling defects in the dilated main pancreatic duct by endoscopic retrograde cholangiopancreatography (ERCP). Accurate preoperative diagnosis was not easy regarding either group. Serum carbohydrate antigen 19-9 (CA 19-9) was more useful for diagnosis in both groups.

CONCLUSIONS

The intraductal papillary neoplasm is a unique clinical entity but not a variant of mucinous cystic neoplasm in terms of sex, age, size, tumor location, or pathologic picture. The pathognomonic findings of ERCP should lead to diagnosis. Very aggressive surgical procedures should be attempted for these two mucin-producing neoplasms with low-grade malignancy.

Intraductal papillary-mucinous tumours represent a distinct group of pancreatic neoplasms: an investigation of tumour cell differentiation and K-ras, p53 and c-erbB-2 abnormalities in 26 patients

Intraductal papillary growth of mucin producing hypersecreting, columnar cells characterizes a group of rare pancreatic exocrine neoplasms which we propose to call intraductal papillary-mucinous tumors (IPMT). We analysed the histopathology of 26 IPMT in relation to gastro-enteropancreatic marker expression, genetic changes and biology. Four IPMT showing only mild dysplasia were considered to be adenomas. Nine tumours displayed moderate dysplasia and were regarded as borderline. Severe dysplasia-carcinoma in situ changes were found in 13 IPMT which were therefore classified as intraductal carcinomas. Six of these carcinomas were frankly invasive and two of these had lymph node metastases. The invasive component resembled mucinous non-cystic carcinoma in all but one tumour which showed a ductal invasion pattern. Immunohistochemically, an intestinal marker type was found in most carcinomas, while gastric type differentiation prevailed among adenomas or borderline tumours. K-ras mutations (seven at codon 12 and one at codon 13) were found in 31% of IPMT (2 adenomas, 1 borderline, 5 carcinomas). Nuclear p53 overexpression was detected in 31% of IPMT (6 carcinomas and 2 borderline IPMT) and correlated with p53 mutations (one at exon 8 and the other at exon 5) in two carcinomas. p53 abnormalities were unrelated to K-ras mutation. c-erbB-2 overexpression was observed in 65% of IPMT, with various grades of dysplasia. Twenty-two of 24 patients are alive and well after a mean post-operative follow-up of 41 months. Only two patients, both with invasive cancer at the time of surgery, died of tumour disease. It is concluded that pancreatic IPMT encompass neoplasms which, in general, have a favorable prognosis, but are heterogeneous in regard to grade of dysplasia and marker expression. Adenoma, borderline tumour, intraductal carcinoma and invasive carcinoma can be differentiated. p53 changes but not K-ras mutation or c-erbB-2 overexpression are related to the grade of malignancy. Most IPMT differ in histological structure, marker expression and behaviour from ductal adenocarcinoma.

Intraductal papillary carcinoma of the pancreas

We report a case of intraductal papillary adenocarcinoma of the distal pancreatic duct. Although a rare subgroup of exocrine pancreatic tumors, their diagnosis is an important one in view of their favorable prognosis with pancreatectomy. Because of the established behavior of villous tumors of the colon, to which they are similar histologically, these tumors should be resected, even if biopsy shows benign disease. Patients should be followed radiologically for recurrence or the development of new adenoma following resection.