Intraductal papillary mucinous tumors and mucinous cystic tumors of the pancreas: imaging

Most cystic lesions of the pancreas are nonneoplastic and inflammatory in nature. However, approximately 5%–15% of cystic pancreatic masses may be neoplastic. Among the cystic neoplasms are the mucin-producing tumors, both the intraductal papillary mucinous neoplasms and the mucinous cystic neoplasms. Their imaging features on contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) can assist in the differentiation of these lesions. The imaging findings of both intraductal papillary mucinous neoplasm and mucinous cystic neoplasm are reviewed with attention to CT and MRI.     

Intraductal papillary mucinous neoplasm and the pancreatic incidentaloma

Asymptomatic pancreatic lesions (APL) are a commonly encountered problem in today's pancreatic surgical practices. Current literature regarding etiologies and incidence of APLs, particularly intraductal papillary mucinous neoplasm (IPMN), is presented. APLs constitute a wide spectrum of pathology (solid/cystic, benign/premalignant/malignant) but, overall, IPMN is now the most common diagnosis. The Sendai Guidelines and their function as a basis for risk stratification in branch duct IPMN are presented. The importance of traditionally analyzed cyst characteristics including size, presence of mucin or nodules and cyst fluid aspirate as indicators of malignancy is emphasized, noting also the potential correlation of main duct dilatation, thickened septae and elevated cyst fluid CEA with increased risk of malignancy. Current complication rates after resection of APLs are reviewed and found to be generally equivalent to those for symptomatic resections. A potential multidisciplinary treatment strategy is offered considering the costs of surgery versus repeated imaging or follow up endoscopy for these lesions. The decision for intervention is ultimately based on the Sendai Guidelines in the context of the individual patient.     

Diagnostic and therapeutic endoscopic approaches to intraductal papillary mucinous neoplasm

Pancreatic cystic lesions are increasingly identified on routine imaging. One specific lesion, known as intraductal papillary mucinous neoplasm (IPMN), is a mucinous, pancreatic lesion characterized by papillary cells projecting from the pancreatic ductal epithelium. The finding of mucin extruding from the ampulla is essentially pathognomonic for diagnosing these lesions. IPMNs are of particular interest due to their malignant potential. Lesions range from benign, adenomatous growths to high-grade dysplasia and invasive cancer. These mucinous lesions therefore require immediate attention to determine the probability of malignancy and whether observation or resection is the best management choice. Unresected lesions need long-term surveillance monitoring for malignant transformation. The accurate diagnosis of these lesions is particularly challenging due to the substantial similarities in morphology of pancreatic cystic lesions and limitations in current imaging technologies. Endoscopic evaluation of these lesions provides additional imaging, molecular, and histologic data to aid in the identification of IPMN and to determine treatment course. The aim of this article is to focus on the diagnostic and therapeutic endoscopic approaches to IPMN.     

Predicting malignant intraductal papillary mucinous neoplasm: a single-center review

Background

The purpose of this study was to examine the characteristics of pancreatic intraductal papillary mucinous neoplasm (IPMN) in our institution and the selection for resection. Recent publications, including those from the International Consensus Guidelines and the Mayo Clinic, set forth criteria for resection. However, these criteria differ in the definition of main duct IPMN, which is an indication to resect.

Methods

Sixty patients from a single institution were retrospectively reviewed between 2000 and 2009.

Results

Thirteen percent of patients had high-grade dysplasia, and 22% had invasive cancer. In multivariate analysis, factors associated with a lower risk of carcinoma were female sex (P = .039) and size <3 cm (P = .024). Patients were retrospectively evaluated with Mayo and International Consensus Guidelines. Eight patients had a diagnosis that would have changed from main duct to branch duct if the International Consensus Guidelines were used. Of these 8, there were 2 cancers. If the International Consensus Guidelines were applied instead of the Mayo, both cancers would have been resected, but 2 patients without cancer would have been spared an operation.

Conclusions

Twenty-two percent of resected patients had invasive cancer, and they had significantly worse survival (37 vs 85 months, P = .032). In our patient group, application of the International Consensus Guidelines identified all malignant IPMN and would have prevented 2 nontherapeutic resections when compared with the Mayo criteria.     

Intraductal papillary mucinous neoplasm of the pancreas associated with neuroendocrine tumor: A case report

IntroductionIntraductal papillary mucinous neoplasm is an uncommon cystic tumor of pancreas that can be associated with ductal adenocarcinoma. Coexistence of pancreatic IPMN and neuroendocrine tumor is very rare. Here, we report the imaging features of mixed type intraductal papillary mucinous neoplasia of the pancreas with high grade dysplasia together with neuroendocrine carcinoma and perform review of the literature.PresentationA 68-year old patient has been evaluated for possible IPMN that was suspected during ultrasound. MRI revealed main and side branch duct dilatations. At the head, a contrast enhancing nodular lesion was identified. Due to the presence of high risk stigmata according to guidelines, surgery was performed. Histopathological examination revealed an unusual association, including mixed type IPMN and neuroendocrine carcinoma.DiscussionThe concomitant occurrence of pancreatic IPMN and neuroendocrine tumor has been reported in case studies and brief reviews. Yet, the imaging findings and underlying molecular mechanisms of this entity has not been fully understood. In addition to this unusual association, pancreatic intraepithelial neoplasia was also detected in the present case. Although majority of neuroendocrine tumor associated IPMNs were reported to be having low grade dysplasia, our patient had high grade dysplasia. Further studies and reviews with larger groups are needed to establish imaging features and underlying molecular mechanisms of this rare association.ConclusionAlthough the major concern during work-up of IPMN is presence of associated pancreatic ductal adenocarcinoma, the possibility of neuroendocrine tumor, in the presence of a hypervascular solid foci on imaging studies should be kept in mind.     

胰腺导管内乳头状黏液性肿瘤的诊断与治疗

目的提高对胰腺导管内乳头状黏液性肿瘤(IPMTs)的认识,以改善其诊治水平。方法对1993年5月至2003年12月收治的15例IPMTs病人的临床、影像学表现及病理资料作回顾性分析。结果15例中男性12例,女性3例。年龄33～76岁,平均58岁。上腹痛为最常见症状。B超和CT检查,均提示有不同程度的胰管扩张和囊实性占位。11例行ERCP检查,发现十二指肠乳头肿大和黏液溢出者7例。14例行手术治疗(胰十二指肠切除术12例,胰体尾切除1例,全胰切除1例)。术后病理诊断胰头导管内乳头状黏液性腺癌3例、导管内乳头状黏液性腺瘤伴局部癌变6例、胰头导管内乳头状黏液性腺瘤伴不典型增生3例、胰头导管内乳头状黏液性腺瘤2例,术后除1例因肝广泛转移而死亡外,其余病人均健在,存活期最长1例已13年。结论胰腺有囊实性占位伴胰管全程扩张的病人应考虑IPMTs,ERCP发现十二指肠乳头增大有黏液溢出者可确诊该疾病。手术切除是最有效的治疗,术后预后良好。     

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.     

胰腺导管内乳头状黏液肿瘤的分子病理学研究进展

胰腺导管内乳头状黏液肿瘤(IPMN)是一种较少见的胰腺囊性肿瘤,具有恶变为胰腺导管腺癌的风险,且一旦发生恶变,预后较差。目前国内外针对IPMN的研究较少,因此,更好地理解其发生发展的分子病理学机制对于该疾病的诊断、治疗和预后改善具有重要意义。已发现多种癌基因、抑癌基因、信号通路等分子参与了IPMN的发生发展及恶变过程,笔者着重对IPMN的分子病理学研究进展进行综述。     

Intraductal papillary mucinous neoplasm originating from a jejunal heterotopic pancreas: report of a case

We report a rare case of an intraductal papillary mucinous neoplasm (IPMN) originating from a jejunal heterotopic pancreas, found incidentally during surgery. A 75-year-old woman was referred to our department for surgical treatment of an abdominal aortic aneurysm (AAA) and a concurrent oropharyngeal tumor. During surgery to correct the AAA, we found a jejunal tumor incidentally and performed partial resection of the jejunum. Microscopically, the jejunal tumor showed dilated ducts containing intraluminal papillae lined with mucinous epithelium with low-grade cytological and architectural atypia within the pancreatic tissue. Immunohistochemical staining revealed MUC1 (?), MUC2 (?), MUC5AC (+), and MUC6 (?) proteins. To the best of our knowledge, only six cases of IPMN originating from a heterotopic pancreas have been reported in English, and this is the first report of an IPMN originating from a jejunal heterotopic pancreas.     

Intraductal papillary mucinous neoplasm of the pancreas with a bifid pancreatic duct

A bifid pancreatic duct presenting a major bifurcation in the main pancreatic duct is one of the anatomical variations of the pancreatic ducts. We encountered a 71-year-old female with a 5-cm-diameter branch duct intraductal papillary mucinous neoplasm of the pancreas in whom preoperative endoscopic retrograde pancreatography demonstrated an anomalous bifurcation of the main pancreatic duct at the body of the pancreas. We performed a distal pancreatectomy, instead of a middle pancreatectomy, with a cutting line at the downstream pancreas to the duct bifurcation point. Intraoperative ultrasonography was useful to confirm the exact location of the pancreatic duct bifurcation as well as the tumor extension. The procedure resulted in a favorable outcome without any postoperative complications. Although a bifid pancreatic duct is an unusual anomalous condition, this case should alert surgeons to be aware of such anatomical variants when performing pancreatic resection, otherwise, incurable pancreatic complications may occur postoperatively.     

Intraductal Papillary Mucinous Tumor of the Pancreas in a Young Man: Report of a Case

We report the rare case of an intraductal papillary mucinous tumor (IPMT) in a man younger than 30 years of age. The patient was admitted with upper abdominal pain and an elevated amylase level of 662 IU/l. Ultrasonography showed a cystic mass in the pancreatic body and endoscopic retrograde cholangiopancreatography (ERCP) revealed a dilated pancreatic duct with a filling defect communicating with the tumor. He was successfully treated by segmental resection, which seems to be the best surgical option for pancreatic body tumors since it results in long-term survival and preserves as much pancreatic parenchyma as possible. Nevertheless, it can only be done in the absence of additional nodules along the pancreatic duct. A pathological diagnosis of intraductal papillary adenocarcinoma of the noninvasive type was confirmed, and both stumps were free of tumor. Received: August 8, 2001 / Accepted: July 2, 2002 Reprint requests to: T. Tokoro     

Intraductal papillary neoplasm of the bile duct: a case report

Intraductal papillary neoplasm of the bile duct (IPNB) is a rare variant of bile duct tumors, characterized by papillary growth within the bile duct lumen and is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. IPNBs are mainly found in patients from Far Eastern areas, where hepatolithiasis and clonorchiasis are endemic. The Western experience, however, remains limited. In this article, we report a 56-year-old man, referred to our hospital because of deranged liver function tests. Further imaging modalities showed a cystic lesion of 9?cm diameter, arising from the left hepatic duct. Inlying was a heterogeneous, lobulated mass. The patient underwent a left hemihepatectomy and adjuvant chemotherapy. Despite recent advanced technologies, diagnosis of IPNB is still challenging, especially in western countries due to its rarity. Early identification and resection of lesions, even in asymptomatic or minimally symptomatic patients, are however important prognostic factors.     

分支胰管型胰腺导管内乳头状黏液瘤临床分析

目的探讨分支胰管型胰腺导管内乳头状黏液瘤(BD-IPMN)的治疗策略。方法结合最新文献复习回顾性分析2例BD-IPMN患者的临床资料。对BD-IPMN的治疗策略、恶变预测等进行探讨,以提高对BD-IPMN的认识和治疗水平。结果2例患者手术过程顺利。患者1术后出现B级胰瘘,患者2出现一过性生化瘘,均经通畅引流、对症及支持治疗后顺利出院。患者1病理提示IPMN伴局灶导管周围腺体不典型增生。患者2病理提示IPMN伴上皮轻-中度异型增生。随访6~12个月,2例患者均未发生复发、转移。结论BD-IPMN作为一种低恶性潜能的肿瘤,尚缺乏有效的指标或方法精准预测其恶性潜能。手术是目前唯一有效的治疗方法,但外科治疗策略的制定需结合患者的依从性、意愿,以及预期寿命和手术风险等因素。应谨慎把握老年及有严重合并症患者的手术指征。     

胰腺导管内乳头状黏液性肿瘤27例诊治分析

目的总结胰腺导管内乳头状黏液性肿瘤(IPMN)的诊治经验,寻找术前预测浸润性IPMN的指标.方法将2003年9月-2010年7月手术治疗的27例胰腺IPMN病例分为浸润性与非浸润性IPMN两组,分析比较两组间术前资料的差异.结果浸润性IPMN 15例,非浸润性IPMN12例.两组间术前梗阻性黄疸发病率、肿瘤最大直径、血...     

Intraductal papillary mucinous neoplasms of the pancreas with multifocal involvement of branch ducts

Introduction

The appropriate management of patients with branch-duct intraductal papillary mucinous neoplasm (BD-IPMN) with multiple involvements of branch ducts (multifocal BD-IPMN) remains challenging.

Patients and methods

Our database of patients affected by IPMN was queried to identify patients with a clinicoradiologic or a pathologic diagnosis of multifocal BD-IPMN between January 1990 and December 2006.

Results

One hundred thirty-one patients (52 male and 79 female; median age 67 years) had a clinicoradiologic or a histopathologic diagnosis of multifocal BD-IPMN. Ten patients (7.6%) underwent surgery. After a median follow-up of 40 months (range 12 to 127) all the 121 patients conservatively managed are alive, and none underwent surgery during follow-up. One patient with invasive carcinoma developed hepatic metastases and died of disease 88 months after surgery.

Comments

Patients with branch-side IPMN can be conservatively managed, but when multifocality is present follow-up may be problematic because of the number of lesions to be evaluated. The nonoperative management of well-selected patients with BD-IPMN, even in the multifocal setting, seems to be safe and reliable.