Clinicopathological features of patients with concomitant intraductal papillary mucinous neoplasm of the pancreas and pancreatic endocrine neoplasm

Pancreatic mixed acinar-neuroendocrine carcinoma with intraductal growth: A case report with radiologic-pathologic correlations

Pancreatic mixed acinar-neuroendocrine carcinomas are rare malignant tumors of the pancreas. They are composed histologically of both acinar and neuroendocrine cells. The pancreatic duct is known to be an important site of tumor growth for acinar cell carcinomas, neuroendocrine tumors, and intraductal tubulopapillary neoplasms. To the best of our knowledge, there has been only 1 report of a mixed acinar-neuroendocrine carcinoma growing into the pancreatic duct and no reports detailing imaging findings with this tumor. We here report a 69-year-old man who presented with worsening glycemic control. Multiphase contrast-enhanced computed tomography and magnetic resonance imaging revealed a well-circumscribed mass with poor contrast enhancement in the pancreatic tail region of the pancreatic duct. The intraductal mass showed diffusion restriction on magnetic resonance imaging. These imaging findings are consistent with the expansive, smooth-surfaced polypoid tumor of low vascularity and high cellularity that was diagnosed pathologically. Mixed acinar-neuroendocrine carcinomas should be included in the differential diagnosis of intraductal tumors of the pancreas with poor contrast enhancement and diffusion restriction.

Intraductal Papillary Mucinous Neoplasm of the Pancreas: A Challenging Diagnosis

Intraductal papillary mucinous neoplasm of the pancreas (IPMN) was classified as a distinct entity from mucinous cystic neoplasm by the WHO in 1995. It represents a mucin-producing tumor that originates from the ductal epithelium and can evolve from slight dysplasia to invasive carcinoma. In addition, different aspects of tumor progression may be seen in the same lesion. Three types are recognized, the branch duct variant, the main duct variant, which shows a much higher prevalence for malignancy, and the mixed-type variant, which combines branch and main duct characteristics. Advances in cross-sectional imaging have led to an increased rate of IPMN detection. The main imaging characteristic of IPMN is the dilatation of the pancreatic duct without the presence of an obstructing lesion. The diagnosis of a branch duct IPMN is based on the proof of its communication with the main pancreatic duct on MRI-MRCP examination. Early identification by imaging of the so-called worrisome features or predictors for malignancy is an important and challenging task. In this review, we will present recent imaging advances in the diagnosis and characterization of different types of IPMNs, as well as imaging tools available for early recognition of worrisome features for malignancy. A critical appraisal of current IPMN management guidelines from both a radiologist's and surgeon's perspective will be made. Special mention is made of complications that might arise during the course of IPMNs as well as concomitant pancreatic neoplasms including pancreatic adenocarcinoma and pancreatic endocrine neoplasms. Finally, recent research on prognostic and predictive biomarkers including radiomics will be discussed.

Case report: composite pancreatic intraductal papillary mucinous neoplasm and neuroendocrine tumor: a new mixed neuroendocrine-non-neuroendocrine neoplasm?

BACKGROUND

Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) of the pancreas are extremely rare. Their pathogenesis and molecular landscape are largely unknown. Here, we report a case of mixed pancreatic intraductal papillary mucinous neoplasm (IPMN) and well-differentiated neuroendocrine tumor (NET) and identify its genetic alterations by next-generation sequencing (NGS).

CASE PRESENTATION

A fifty-year-old male was admitted into the hospital for evaluation of a pancreatic lesion detected during a routine examination. Abdominal ultrasound indicated a hypoechoic mass of 2.6 cm at the head of the pancreas. Malignancy was suspected and partial pancreatectomy was performed. Thorough histopathological examination revealed a mixed IPMN-NET. In some areas, the two components were relatively separated, whereas in other areas IPMN and NET grew in a composite pattern: The papillae were lined with epithelial cells of IPMN, and there were clusters of NET nests in the stroma of papillary axis. NGS revealed shared somatic mutations (KRAS, PCK1, MLL3) in both components. The patient has been uneventful 21 months after the surgery.

CONCLUSIONS

Our case provides evidence of a common origin for mixed IPMN-NET with composite growth features. Our result and literature review indicate that KRAS mutation might be a driver event underlying the occurrence of MiNEN. We also recommend the inclusion of mixed non-invasive exocrine neoplasms and neuroendocrine neoplasms into MiNEN.

A rational approach to postoperative surveillance for resected non-functional pancreatic neuro-endocrine tumours

BACKGROUND

Non-functional pancreatic neuroendocrine tumours (NF-PNETs) are rare and have highly variable outcomes. Current guidelines recommend surveillance for NF-PNETs <2 cm. Patients who ultimately have surgical resection are at risk of disease recurrence, and data to support postoperative surveillance protocols are lacking. The aims of this study were to i) identify post-operative predictors of recurrence and ii) risk stratify patients at risk of recurrence.

METHODS

Consecutive patients who underwent surgery for NF-PNETs between 2002 and 2015 were identified retrospectively. Data were collected on demographics, pre-operative laboratory results and histopathological tumour characteristics. Statistical analyses were based on penalised Cox-regression modelling and a decision-tree model. Comparison of the variables identified was performed using ROC curves to identify the most sensitive and specific variable associated with disease recurrence.

RESULTS

We identified 73 patients (38 males) with a median age of 61.5 years (range: 31-79). The median period of follow-up was 49 months (5-131). During follow up, 10 deaths (13.9%) were recorded and disease recurrence occurred in 12 patients (16.4%). The Kaplan-Meier predicted 1-,3- and 5-year recurrence-free survival rates were 98.6% (95% CI = 95.9, 100%), 85.4% (76.9-94.8%) and 72% (58.7-88.2%) respectively. Cox multivariate analysis identified poor tumour differentiation (WHO G3 grade) and lymph node ratio (LNR) as independent predictors for recurrence (p < 0.05). A simple criterion of 'tumour grade G3 or LNR ≥0.1' was found to be sensitive and specific in detecting disease recurrence.

CONCLUSION

Our results have identified a simple and sensitive criterion for risk stratifying post-resection surveillance. Prospective validation in larger patient cohort is now warranted.

Double primary tumors of the pancreas: A case report

RATIONALE

Adenocarcinoma and neuroendocrine tumors are a very rare combination of double primary pancreas tumor.

PATIENT CONCERNS

A Whipple operation was initially performed on a 64-year-old man to remove an adenocarcinoma. Four years after the operation, surveillance- computed tomography revealed abnormal findings of the pancreas. Recurrent adenocarcinoma and neuroendocrine tumor involving different sites of the remnant pancreas were simultaneously detected and characterized on computed tomography and magnetic resonance imaging.

DIAGNOSES

The patient was diagnosed with recurrent adenocarcinoma and neuroendocrine tumor in the post-operative pancreas.

INTERVENTIONS

Radical pancreatosplenectomy was performed. The patient underwent subsequent chemotherapy and radiotherapy.

OUTCOMES

No tumor recurrence was found during the 5 years of follow-up visits.

LESSONS

The possibility of multiple primary tumors of different histological origin should be considered when multiple different pancreatic lesions are detected on images. Computed tomography (CT) and magnetic resonance imaging (MRI) play key roles in the management of multiple tumors in the pancreas.

Synchronous pancreatic tumors in a patient with history of Wilms tumor: A case of pancreatic adenocarcinoma and lipid-rich neuroendocrine tumor diagnosed by cytopathology

Synchronous tumors represent a very small portion of pancreatic tumors. Although there is a higher incidence of secondary malignant neoplasms (SMN) in patients with history of Wilms tumor (WT), pancreatic tumors are very infrequent SMNs in this population. We report the first case of synchronous pancreatic tumors in a patient with history of WT. Two separated pancreatic lesions were identified by abdominal computerized tomography (CT) scan. Fine-needle aspiration of both lesions was performed for cytopathology examination. A pancreatic adenocarcinoma was diagnosed in the head of pancreas, and the pancreatic body lesion was found to be a neuroendocrine tumor (NET). The NET had characteristic vacuolated lipid-rich cytoplasm. Further molecular testing was done on both tumors, but no common cancer-associated mutation was found.

Synchronous intraductal papillary mucinous neoplasm and a pancreatic neuroendocrine tumor: more than a coincidence?

BACKGROUND

Although the association between intraductal papillary mucinous neoplasm of the pancreas (IPMN) and pancreatic neuroendocrine tumor (PNET) has been increasingly reported, whether this association is real or coincidence remains unclear. We report a case of synchronous IPMN and a PNET which were diagnosed preoperatively and discuss the tumorigenesis, clinicopathological features and management of these rare tumors based on the published literature.

CASE REPORT

A 56-year-old male was incidentally diagnosed with a 14 mm branch duct IPMN and a 3.6 mm non-functional PNET during an evaluation due to persistent upper abdominal pain via endoscopic ultrasound. Close follow-up of the patient was decided as the IPMN had no worrisome features. A review of twenty-two previously reported cases of synchronous IPMN and PNET indicated that: a) only seven cases were diagnosed preoperatively; b) abdominal pain was the main presenting symptom; c) IPMN was the dominant tumor and presented with low grade dysplasia; d) the PNET was small and non-functional and had an indolent behavior; and e) only one case underwent radiologic follow-up.

DISCUSSION

IPMN are associated with other pancreatic and extrapancreatic malignancies. Thus, the entire pancreatic parenchyma should be examined closely during the evaluation of an IPMN in order to exclude other pancreatic lesions, for example, a PNET.

Collision of ductal adenocarcinoma and neuroendocrine tumor of the pancreas: a case report and review of the literature

BACKGROUND

Simultaneous occurrence of exocrine and neuroendocrine tumors of the pancreas is very infrequent. We report a patient with an endocrine tumor in the pancreatic-duodenal area and extensive exocrine carcinoma involving the whole pancreas.

CASE PRESENTATION

A 69-year-old woman was hospitalized in May 2016 for epigastric pain and weight loss. Her past medical history revealed an undefined main pancreatic duct dilation that was subsequently confirmed at CT scan (23 mm) and endoscopic ultrasound. There was no evidence of pancreatic masses, but the cephalic portion of the main pancreatic duct presented hypoechoic nodules. A diagnosis of the main-duct intraductal papillary mucinous neoplasm was made, and the patient underwent total pancreatectomy. Pathological examination showed a collision tumor constituted by a ductal adenocarcinoma involving the whole pancreas and a neuroendocrine tumor located in the duodenal peripancreatic wall and the head of the pancreas. There was one peripancreatic lymph node metastasis from the ductal adenocarcinoma and eight node metastases from the neuroendocrine tumor. These findings suggested a diagnosis of collision of neuroendocrine and ductal adenocarcinomas of the pancreas. The postoperative course was uneventful.

CONCLUSIONS

The coexistence of pancreatic endocrine and exocrine tumors is very uncommon. When present, problems in differential diagnosis may arise between mixed exocrine-endocrine carcinoma or the collision of separate tumors.

Mixed Neuroendocrine-Nonneuroendocrine Neoplasms (MiNENs): Unifying the Concept of a Heterogeneous Group of Neoplasms

The wide application of immunohistochemistry to the study of tumors has led to the recognition that epithelial neoplasms composed of both a neuroendocrine and nonneuroendocrine component are not as rare as traditionally believed. It has been recommended that mixed neuroendocrine-nonneuroendocrine epithelial neoplasms are classified as only those in which either component represents at least 30 % of the lesion but this cutoff has not been universally accepted. Moreover, since their pathogenetic and clinical features are still unclear, mixed neuroendocrine-nonneuroendocrine epithelial neoplasms are not included as a separate clinicopathological entity in most WHO classifications, although they have been observed in virtually all organs. In the WHO classification of digestive tumors, mixed neuroendocrine-nonneuroendocrine neoplasm is considered a specific type and is defined as mixed adenoneuroendocrine carcinoma, a definition that has not been accepted for other organs. In fact, this term does not adequately convey the morphological and biological heterogeneity of digestive mixed neoplasms and has created some misunderstanding among both pathologists and clinicians. In the present study, we have reviewed the literature on mixed neuroendocrine-nonneuroendocrine epithelial neoplasms reported in the pituitary, thyroid, nasal cavity, larynx, lung, digestive system, urinary system, male and female genital organs, and skin to give the reader an overview of the most important clinicopathological features and morphological criteria for diagnosing each entity. We also propose to use the term "mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN)" to define and to unify the concept of this heterogeneous group of neoplasms, which show different characteristics mainly depending on the type of neuroendocrine and nonneuroendocrine components.

Pathologic Evaluation and Reporting of Intraductal Papillary Mucinous Neoplasms of the Pancreas and Other Tumoral Intraepithelial Neoplasms of Pancreatobiliary Tract: Recommendations of Verona Consensus Meeting

BACKGROUND

There are no established guidelines for pathologic diagnosis/reporting of intraductal papillary mucinous neoplasms (IPMNs).

DESIGN

An international multidisciplinary group, brought together by the Verona Pancreas Group in Italy-2013, was tasked to devise recommendations.

RESULTS

(1) Crucial to rule out invasive carcinoma with extensive (if not complete) sampling. (2) Invasive component is to be documented in a full synoptic report including its size, type, grade, and stage. (3) The term "minimally invasive" should be avoided; instead, invasion size with stage and substaging of T1 (1a, b, c; ≤ 0.5, > 0.5-≤ 1, > 1 cm) is to be documented. (4) Largest diameter of the invasion, not the distance from the nearest duct, is to be used. (5) A category of "indeterminate/(suspicious) for invasion" is acceptable for rare cases. (6) The term "malignant" IPMN should be avoided. (7) The highest grade of dysplasia in the non-invasive component is to be documented separately. (8) Lesion size is to be correlated with imaging findings in cysts with rupture. (9) The main duct diameter and, if possible, its involvement are to be documented; however, it is not required to provide main versus branch duct classification in the resected tumor. (10) Subtyping as gastric/intestinal/pancreatobiliary/oncocytic/mixed is of value. (11) Frozen section is to be performed highly selectively, with appreciation of its shortcomings. (12) These principles also apply to other similar tumoral intraepithelial neoplasms (mucinous cystic neoplasms, intra-ampullary, and intra-biliary/cholecystic).

CONCLUSIONS

These recommendations will ensure proper communication of salient tumor characteristics to the management teams, accurate comparison of data between analyses, and development of more effective management algorithms.

The clinical utility of a novel blood-based multi-transcriptome assay for the diagnosis of neuroendocrine tumors of the gastrointestinal tract

OBJECTIVES

Current monoanalyte blood-based biomarkers for the diagnosis and follow-up of neuroendocrine tumors (NETs) do not achieve satisfactory metrics of sensitivity and specificity. We report the sensitivity and selectivity of the PCR-based test, the NETest, to detect tumors with reference to other benign and malignant gastrointestinal diseases.

METHODS

A total of 179 cases (gastrointestinal tumors: n=81; pancreatic disease: n=98) were prospectively collected and assessed using the NETest or chromogranin A (CgA) to determine metrics for detecting small intestinal and pancreatic NETs.

RESULTS

For intestinal carcinoids, the accuracy of the NETest was 93% (all NETs positive and 3 (12%) colorectal tumors were positive). CgA was positive in 80%, but 29% (n=7) of colorectal cancers were CgA positive. For pancreatic disease, the NETest accuracy was 94% (96% NETs positive, 2 (6%) of intraductal papillary mucinous neoplasms (IPMNs) were positive). The accuracy of CgA was 56% (29% of pancreatic NETs were CgA positive). Overall, the NETest was significantly more sensitive than CgA for the detection of small intestinal (area under the curve 0.98 vs. 0.75 P<0.0001) and pancreatic NETs (0.94 vs. 0.52, P<0.0001). NETest scores were elevated (P<0.05) in extensive disease and were more accurate (76-80%) than CgA levels (20-32%). The metrics of the multianalyte NETest met the performance criteria proposed by the National Institutes of Health for biomarkers, whereas CgA measurement did not.

CONCLUSIONS

This study demonstrates that a blood-based multianalyte NET gene transcript measurement of well-differentiated small intestinal and pancreatic neuroendocrine tumor disease is sensitive and specific and outperforms the current monoanalyte diagnostic strategy of plasma CgA measurement.

Increased risk of second malignancy in pancreatic intraductal papillary mucinous tumors: Review of the literature

AIM: To analyze the available evidence about the risk of extrapancreatic malignancies and pancreatic ductal adenocarcinoma associated to pancreatic intraductal papillary mucinous tumors (IPMNs).

METHODS: A systematic search of literature was undertaken using MEDLINE, EMBASE, Cochrane and Web-of-Science libraries. No limitations for year of publication were considered; preference was given to English papers. All references in selected articles were further screened for additional publications. Both clinical series and Literature reviews were selected. For all eligible studies, a standard data extraction form was filled in and the following data were extracted: study design, number of patients, prevalence of pancreatic cancer and extrapancreatic malignancies in IPMN patients and control groups, if available.

RESULTS: A total of 805 abstracts were selected and read; 25 articles were considered pertinent and 17 were chosen for the present systematic review. Eleven monocentric series, 1 multicentric series, 1 case-control study, 1 population-based study and 3 case report were included. A total of 2881 patients were globally analyzed as study group, and the incidence of pancreatic cancer and/or extrapancreatic malignancies ranged from 5% to 52%, with a mean of 28.71%. When a control group was analyzed (6 papers), the same incidence was as low as 9.4%.

CONCLUSION: The available Literature is unanimous in claiming IPMNs to be strongly associated with pancreatic and extrapancreatic malignancies. The consequences in IPMNs management are herein discussed.

Three synchronous, sporadic and separate periampullary and pancreatic tumors: more than a coincidence?

Three sporadic, synchronous, and separate lesions in the ampulla of Vater and the head of the pancreas presented in an 81-year-old male. One was symptomatic and two were incidental. One was detected preoperatively (the ampullary lesion) and two by examination of the resected specimen (the neuroendocrine and pancreatic carcinomas). The case is summarized and the literature and the issue of commonality are reviewed.

IPMN: surgical treatment

PURPOSE

Cystic pancreatic tumors are being detected more frequently, and particularly, intraductal papillary mucinous neoplasia (IPMN) has recently attracted increased attention. The detection rate of IPMN has increased over the last decade; however, management of this neoplasm remains controversial.

METHODS

Based on a review of the relevant literature and the international guidelines, we discuss the diagnostic evaluation of IPMN, its treatment, and prognosis.

RESULTS

While IPMN represents only a distinct minority of all pancreatic cancers, they appear to be a relatively frequent neoplastic form of pancreatic cystic neoplasm. It may not be possible to differentiate main duct disease from branch duct disease (MD-IPMN vs. BD-IPMN) prior to surgery. This distinction has not only an impact on treatment but also on prognosis, as MD-IPMN is more often malignant. IPMN has updated consensus guideline indications for conservative and surgical resection.

CONCLUSIONS

Since patients with IPMN of the pancreas are at risk of developing recurrent IPMN and pancreatic ductal adenocarcinoma in the remnant pancreas and extrapancreatic malignancies, early recognition, treatment, and systemic surveillance are of great importance. No conclusions can be drawn from the available evidence with respect to the efficacy of surveillance and follow-up treatment programs. A better understanding of the natural course of IPMN and the biology of pancreatic cancer is mandatory to enable further diagnostic and treatment improvements.

Collision of extensive exocrine and neuroendocrine neoplasms in multiple endocrine neoplasia type 1 revealed by cytogenetic analysis of loss of heterozygosity: a case report

The combination of exocrine and neuroendocrine neoplasms is rarely found in the pancreas. These combined lesions vary from a clonal tumor with mixed differentiation to the incidental co-existence of two or more independent tumors, but the differential diagnosis is sometimes difficult. Here we report a case of multiple endocrine neoplasia type 1 (MEN1) with extensive ductal and neuroendocrine neoplastic changes. These two types of tumors admixed markedly in some parts, which made it difficult to determine the pathological diagnosis based on histological findings. Cytogenetic analysis showed that loss of heterozygosity (LOH) of the MEN1 locus exists in neuroendocrine but not in exocrine neoplasms, indicating that independent mechanisms of tumorigenesis may occur in these two types of tumors. This case shows the usefulness of cytogenetic analysis for the diagnosis of combined tumors of the pancreas. Extensive exocrine neoplastic change, including pancreatic intraepithelial neoplasia (PanIN) in virtually all pancreatic ducts and a focus of intraductal papillary mucinous neoplasm (IPMN) with focal invasion, was a distinguishing feature of the present case. The possible association of ductal tumorigenesis and a MEN1 background is discussed.

Intraductal papillary neoplasm of the bile duct accompanying biliary mixed adenoneuroendocrine carcinoma

We present the first case of an intraductal papillary neoplasm of the bile duct (IPNB) accompanying a mixed adenoneuroendocrine carcinoma (MANEC). A 74-year-old woman presented with fever of unknown cause. Laboratory data revealed jaundice and liver injury. Contrast-enhanced computed tomography revealed a 20 mm polypoid tumor in the dilated distal bile duct, which exhibited early enhancement and papillary growth. Upper gastrointestinal endoscopy revealed mucus production from the papilla of Vater, characterized by its protruding and dilated orifice. Endoscopic ultrasonography visualized the polypoid tumor in the distal bile duct, but no invasive region was suggested by diagnostic imaging. Therefore, the initial diagnosis was IPNB. After endoscopic nasobiliary drainage, a pylorus-preserving pancreaticoduodenectomy was performed. Pathological examination of the resected bile duct revealed papillary proliferation of biliary-type cells with nuclear atypia, indicating pancreaticobiliary-type IPNB. In addition, solid portions comprised of tumor cells with characteristic salt-and-pepper nuclei were evident. Immunohistochemistry revealed expression of the neuroendocrine marker synaptophysin in this solid component, diagnosing it as a neuroendocrine tumor (NET). Furthermore, the MIB-1 proliferation index of NET was higher than that of IPNB, and microinvasion of the NET component was found, indicating neuroendocrine carcinoma (NET G3). This unique case of MANEC, comprising IPNB and NET, provides insight into the pathogenesis of biliary NET.

Concomitant pancreatic endocrine neoplasm and intraductal papillary mucinous neoplasm: a case report and literature review

We report a case of concomitant pancreatic endocrine neoplasm (PEN) and intraductal papillary mucinous neoplasm (IPMN). A 74-year-old man had been followed-up for mixed-type IPMN for 10 years. Recent magnetic resonance images revealed an increase in size of the branch duct IPMN in the pancreas head, while the dilation of the main pancreatic duct showed minimal change. Although contrast-enhanced computed tomography and magnetic resonance imaging did not reveal any nodules in the branch duct IPMN, endoscopic ultrasound indicated a suspected nodule in the IPMN. A malignancy in the branch duct IPMN was suspected and we performed pylorus-preserving pancreatoduodenectomy with lymphadenectomy. The resected specimen contained a cystic lesion, 10 x 10 mm in diameter, in the head of the pancreas. Histological examination revealed that the dilated main pancreatic duct and the branch ducts were composed of intraductal papillary mucinous adenoma with mild atypia. No evidence of carcinoma was detected in the specimen. Incidentally, a 3-mm nodule consisting of small neuroendocrine cells was found in the main pancreatic duct. The cells demonstrated positive staining for chromogranin A, synaptophysin, and glucagon but negative staining for insulin and somatostatin. Therefore, the 3-mm nodule was diagnosed as a PEN. Since the mitotic count per 10 high-power fields was less than 2 and the Ki-67 index was less than 2%, the PEN was pathologically classified as low-grade (G1) according to the 2010 World Health Organization (WHO) criteria. Herein, we review the case and relevant studies in the literature and discuss issues related to the synchronous occurrence of the relatively rare tumors, PEN and IPMN.

Concomitant intraductal papillary mucinous neoplasm and neuroendocrine tumor of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) and neuroendocrine tumor (NET) of the pancreas are rare tumors and their association is not expected to be frequent. However, certain studies have suggested that the concomitant occurence of these tumors may be more frequent than previously thought. In the current study, we describe a case of concomitant occurrence of IPMN and NET of the pancreas and review the clinicopathological features of previously published cases and the current one. A 68-year-old female was incidentally found to have dilatation of the main pancreatic duct. A distal pancreatectomy was performed under the clinical diagnosis of IPMN. Histopathological analysis revealed concomitant IPMN (low-grade) and NET G1 of the pancreas. Review of the clinicopathological features of the 15 previously reported cases of concomitant IPMN and NET of the pancreas as well as the present one indicated that: i) this condition mainly affects middle-aged females; ii) the main symptom is abdominal or back pain, or no symptoms; iii) a hormone production symptom was observed in only one case; iv) the most common degree of dysplasia of IPMN is low grade; and v) the size of the NET is not particularly large (average 15.1 mm), although the clinical behavior is not always indolent (metastasis was observed in 3 cases). It is well known that IPMNs are associated with a high incidence of extrapancreatic malignancies, including colorectal and gastric carcinomas. Concomitant pancreatic NET and extrapancreatic malignancies may occur, therefore, systemic surveillance of extrapancreatic neoplasms and detection of concomitant NETs of the pancreas are necessary for patients with IPMN.

Synchronous primary epithelial tumors of the pancreas

INTRODUCTION

Pancreatic incidentalomas are diagnosed at increased rates due to advanced pancreatic imaging. Coexistence of such lesions with another pancreatic pathology, however, is uncommon and their management might be perplexed by the anatomical location and the histological features of the lesion.

PRESENTATION OF CASE

A patient with obstructive jaundice was diagnosed with adenocarcinoma of the pancreatic head and underwent routine pancreatic imaging (CT) which revealed the coexistence of a small cystic lesion at the pancreatic body. Further investigation with MRCP and ERCP was unable to confirm a benign lesion and total pancreatoduodenectomy was performed. Histological examination showed a rare type of mixed serous-mucinous cystadenoma of borderline malignancy at the pancreatic body coexistent with an adenocarcinoma of the pancreatic head.

DISCUSSION

Coexistence of a peripheral pancreatic cystic tumor with a ductal adenocarcinoma of the pancreatic head is a very rare incidence in medical literature. The management of the peripheral lesion is not straightforward and there can be uncertainty as to the extent of the pancreatic resection that may be required.

CONCLUSION

Appropriate preoperative imaging has a significant impact on the definitive management of synchronous pancreatic tumors. Implications of a common pathogenetic pathway are also raised for this rare occurrence of two primary epithelial pancreatic tumors.

Long-term clinical and imaging follow-up of nonoperated branch duct form of intraductal papillary mucinous neoplasms of the pancreas

OBJECTIVES

The aim of our study was to perform a 10-year imaging and clinical prospective follow-up of patients with nonoperated branch duct (BD) intraductal papillary mucinous neoplasms (IPMNs) of the pancreas.

METHODS

Forty-nine patients with BD-IPMN who displayed a low probability for malignancy were followed up including a clinical component and a series of imaging techniques such as computed tomography, magnetic resonance cholangiopancreatography, and endoscopic ultrasonography.

RESULTS

After a mean follow-up period of 77 months, 77.5% of patients remained free of symptoms. An increase in the size and number of BD cysts without mural nodules and with no significant increase of main duct size occurred in 18 patients at an average interval of 47 months. Five patients were operated on owing to recurrent pancreatitis and/or an increase in the size of either cysts or the main duct (mean time delay after diagnosis: 20 months). Pathologically, they were diagnosed as benign adenoma (n = 1) or borderline (n = 4).

CONCLUSIONS

Our long-term clinical and imaging follow-up indicated that none of the patients with BD-IPMNs developed malignancy. Therefore, BD-IPMNs with no signs of malignancy should be managed conservatively. We propose that following a 2-year patient follow-up, biannual imaging follow-ups could be sufficient.

Synchronous solid pseudopapillary neoplasm and intraductal papillary mucinous neoplasm of the pancreas: report of a case

Solid pseudopapillary neoplasm (SPN) of the pancreas, most commonly found in young female subjects, is a rare neoplasm with low potential for malignancy. We report an unusual case of a 66-year-old male patient who had a simultaneous malignant SPN and an intraductal papillary mucinous adenoma (IPMA) of the pancreas. The patient was admitted to our department for the evaluation of the main solid tumor with calcification and small multilocular cystic lesions apart from the main tumor in the pancreatic head. We performed pylorus-preserving pancreaticoduodenectomy to treat the calcified tumor and multilocular cystic lesions. The diagnosis of malignant SPN was confirmed on the basis of histological invasion to the adjacent structures. The separate cystic lesions were diagnosed as a branch-type IPMA. The synchronous occurrence of IPMA and SPN in the present case did not demonstrate that there were tumors maintained through the common abnormal Wnt signaling pathway by immunohistochemical study. To our knowledge, this is the first known case of synchronous SPN and IPMA of the pancreas.

Pseudointraductal papillary mucinous neoplasia caused by microscopic periductal endocrine tumors of the pancreas: a report of 3 cases

Intraductal papillary mucinous neoplasms constitute histologically distinctive pancreatic tumors characterized by cystically dilated pancreatic ducts lined by papillary epithelium, often with extensive mucin production. With increasing awareness of and vigilance for these tumors, there has been a surge in the incidence of intraductal papillary mucinous neoplasms in the last few decades. However, resections of presumed intraductal papillary mucinous neoplasms sometimes reveal other types of cystic lesions. Here we describe 3 cases of small, incidentally identified pancreatic endocrine tumors that focally compressed the main pancreatic duct and presented clinically, radiologically, and grossly as intraductal papillary mucinous neoplasm. The histology of the dilated ducts in all cases lacked convincing features of intraductal papillary mucinous neoplasm, prompting more careful examination of the specimens and eventual identification of small well-differentiated endocrine neoplasms. The constellation of findings represented by pancreatic endocrine neoplasm-associated duct stricture and dilatation can mimic intraductal papillary mucinous neoplasm clinically and pathologically. Awareness of this phenomenon can potentially avoid misdiagnosis of intraductal papillary mucinous neoplasm in such cases.

Solitary concomitant endocrine tumor and ductal adenocarcinoma of pancreas

Pancreatic tumors with combined exocrine and endocrine features are rare. Most reported cases are classified as mixed exocrine and endocrine carcinoma of the pancreas. We report the first case of solitary concomitant endocrine tumor and ductal adenocarcinoma of the pancreas. A 58-year-old patient was admitted for uncontrolled diabetes mellitus and body weight loss. The tumor was fortuitously discovered in the pancreatic tail after a tumor survey panel. Grossly, the solitary tumor had a central fibrous band that clearly divided it into two parts. On microscopic examination, the tumor contained both endocrine and exocrine components distinctly separated by the central fibrous band. The exocrine part showed a poorly-differentiated adenocarcinoma. The endocrine part was strongly immunoreactive to chromogranin, synaptophysin and glucagon. We reviewed the literature on pancreatic tumors with combined exocrine and endocrine features. A simple classification for this group of neoplasms is suggested, including five types: amphicrine, mixed, collision, solitary concomitant and multiple concomitant.

Risk factors for sporadic pancreatic endocrine tumors: a case-control study of prospectively evaluated patients

OBJECTIVES

Pancreatic endocrine tumors (PETs) are heterogeneous tumors with increasing prevalence. Little is known about the molecular pathogenesis and risk factors for the occurrence of sporadic PETs. The aim of this study was to identify the risk factors associated with the occurrence of sporadic PETs.

METHODS

A case-control study comprising 162 sporadic PETs and 648 controls was undertaken. Subjects were interviewed using a specific questionnaire on demographics and potential risk factors, including smoking, alcohol, height, weight, medical history, and family history of cancer. A multiple hierarchical logistic regression analysis was performed with a stepwise variable- selection procedure.

RESULTS

A first-degree family history of any cancer was a significant risk factor (odds ratio (OR) 2.2; 95% confidence interval (CI): 1.5-3.2). Among the different cancer sites, first-degree family history of pancreatic adenocarcinoma was more frequent in PETs than in controls (4.3 vs. 1.2%; P=0.01). A high alcohol intake (OR 4.8; 95% CI: 2.4-9.5), history of chronic pancreatitis (CP) (OR 8.6; 95% CI: 1.4-51), and recent-onset diabetes (OR 40.1; 95% CI: 4.8-328.9) were all independent risk factors. The history of diabetes was also associated with metastatic disease at the time of diagnosis.

CONCLUSIONS

This case-control study identified family history of any cancer (and to a less extent of pancreatic adenocarcinoma), CP, high alcohol intake, and recent-onset diabetes as risk factors for PET, thus suggesting a possible partial overlap with risk factors for exocrine pancreatic carcinogenesis.

Concomitant intraductal papillary mucinous neoplasm and pancreatic endocrine tumour: Report of two cases and review of the literature

It has been suggested that the occurrence of intraductal papillary mucinous neoplasms in association with pancreatic endocrine tumours is more frequent than expected [Goh BK, Ooi LL, Kumarasinghe MP, Tan YM, Cheow PC, Chow PK, et al. Clinicopathological features of patients with concomitant intraductal papillary mucinous neoplasm of the pancreas and pancreatic endocrine neoplasm. Pancreatology 2006;6:520-6]. Up to now, 10 patients with concomitant intraductal papillary mucinous neoplasms and pancreatic endocrine tumours have been reported [Goh BK, Ooi LL, Kumarasinghe MP, Tan YM, Cheow PC, Chow PK, et al. Clinicopathological features of patients with concomitant intraductal papillary mucinous neoplasm of the pancreas and pancreatic endocrine neoplasm. Pancreatology 2006;6:520-6; Zhao X, Stabile BE, Mo J, Wang J, French SW. Nesidioblastosis coexisting with islet cell tumor and intraductal papillary mucinous hyperplasia. Arch Pathol Lab Med 2001;125:1344-7; Marrache F, Cazals-Hatem D, Kianmanesh R, Palazzo L, Couvelard A, O'Toole D, et al. Endocrine tumor and intraductal papillary mucinous neoplasm of the pancreas: a fortuitous association? Pancreas 2005;31:79-83]. In most cases the synchronous existence of both tumours was incidentally discovered after the examination of the surgical specimen. We report two additional patients with intraductal papillary mucinous neoplasms and pancreatic endocrine tumours, in whom both tumours were diagnosed before surgery.

Synchronous and metachronous extrapancreatic malignant neoplasms in patients with intraductal papillary-mucinous neoplasm of the pancreas

BACKGROUND/AIMS

Patients with intraductal papillary-mucinous neoplasm (IPMN) of the pancreas are likely to have a better prognosis than those with conventional pancreatic ductal adenocarcinoma. Recently there have been some reports on extrapancreatic malignant neoplasms (EPM) occurring in patients with IPMN. The purpose of this study was to discover the characteristic features of IPMN with EPM compared with IPMN without EPM.

METHODS

61 patients with IPMN who underwent surgery at Tohoku University Hospital between 1988 and 2006 were retrospectively analyzed.

RESULTS

The 61 patients with IPMN in this study comprised 25 with intraductal papillary-mucinous adenomas (IPMA) and 36 with intraductal papillary-mucinous carcinomas (IPMC) including 6 with invasive carcinomas. Synchronous and metachronous EPM were observed in 15 out of the 61 patients (24.6%). Three of these patients, including 2 with IPMA and 1 with invasive carcinoma associated with IPMC, died of the EPM. None of the features, including sex, age, smoking, family history, macroscopic types (main duct type or branch duct type), histological types (gastric, intestinal, pancreatobiliary or oncocytic), and aberrant expression of molecules including CDKN2A, TP53, SMAD4 and DUSP6, except for the histological diagnoses were associated with the occurrence of EPM, i.e., the EPM occurred more often in patients with IPMA (10 out of 25) than in those with IPMC (5 out of 36) in our series (p = 0.0199 by the chi(2) test, p = 0.0330 by Fisher's exact probability test, p = 0.0422 by Yates' correction).

CONCLUSION

Patients with IPMA were more likely to have EPM than those with IPMC. Patients with IPMA are usually expected to have a fair prognosis but EPM could be fatal in some of them, so it must be noted during follow-up.

[Intraductal papillary mucinous tumor: diagnostic and therapeutic approach]

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

A carrier of both MEN1 and BRCA2 mutations: case report and review of the literature

High-penetrance autosomal dominant cancer susceptibility genes such as BRCA2 and MEN1 result in specific patterns of cancers in individuals who inherit germline mutations. Their incidence in the population is relatively low, however, and it is highly unusual to identify individuals with two or more inherited cancer gene mutations. We describe a family with multiple cases of MEN1-associated cancers as well as pancreatic adenocarcinoma, ovarian cancer, and male breast cancer, in which we identified germline mutations in both MEN1 and BRCA2. To our knowledge, this is the first report of a patient with both MEN1 and BRCA2 mutations and with a personal history of hyperparathyroidism and pancreatic neuroendocrine tumors.

Cystic neoplasms of the exocrine pancreas

The increasing use of radiological imaging has led to greater detection of small and asymptomatic cystic lesions of the pancreas. Most are resectable, but not all are neoplastic. This review provides an update on the histopathology, immunohistochemistry, molecular biology, pathogenesis and management of cystic neoplasms of the exocrine pancreas. These include the serous, the mucinous cystic, the intraductal papillary mucinous and the solid pseudopapillary neoplasms. Recently reported variants are described and very rare cystic variants of other pancreatic epithelial and mesenchymal neoplasms are briefly mentioned.