Uncinatectomy: a novel surgical option for the management of intraductal papillary mucinous tumors of the pancreas

An intraductal papillary mucinous tumor (IPMT) is a rare cystic lesion of the pancreas, comprising only 1% of all pancreatic exocrine neoplasms. The prognosis for these lesions is typically favorable as compared with invasive ductal carcinomas. Nevertheless, the management of IPMTs involves surgical resection due to their malignant potential. When located in the pancreatic head, the conventional treatment for IPMT is pancreatoduodenectomy. Some authors have advocated limited pancreatectomy for low-grade IPMTs of the pancreas, thereby decreasing the morbidity of more extensive resection. In this report, we describe our technique of minimal pancreatectomy, whereby the uncinate process and associated branch duct were completely extirpated while preserving remainder of the pancreatic head, duodenum, and pancreatic ducts. The case presented underscores the feasibility and advantages of minimal pancreatic resection in the management of such tumors.     

Favorable Response After Gemcitabine-Radiotherapy for Invasive Pancreatic Intraductal Papillary Mucinous Neoplasm: A Case Report

The efficacy of chemoradiotherapy for invasive pancreatic ductal carcinoma derived from an intraductal papillary mucinous neoplasm (IPMN) has not been established. The subject of the present report was a 53-year-old man admitted for the treatment of IPMN. The tumor, located in the pancreatic body, was of the mixed type of IPMN, and it involved the branch duct, where it was 38 mm in diameter, and the main duct, where it was 6 mm in diameter. Distal pancreatectomy was performed and the postoperative course was uneventful; however, histopathologic diagnosis revealed invasive ductal carcinoma with a positive surgical margin in the pancreatic duct. Although total pancreatectomy was recommended, chemoradiotherapy (50.4-Gy irradiation and gemcitabine) was preferred by the patient. At 9-month follow up, computed tomography and magnetic resonance imaging showed a cystic mass at the surgical margin of the pancreas. Endoscopic ultrasonography showed a 44-mm cystic lesion with nodules in the remnant pancreas, on the basis of which he underwent total pancreatectomy. Pathologic examination of the resected specimen revealed absence of the epithelium at the surgical margin of the main pancreatic duct, and malignant cells were not detected.     

Role of frozen section assessment for intraductal papillary and mucinous tumor of the pancreas

Intraductal papillary mucinous neoplasms (IPMN) of the pancreas include a spectrum of dysplasia ranging from minimal mucinous hyperplasia to invasive carcinoma and are extensive tumors that often spread along the ductal tree. Several studies have demonstrated that preoperative imaging is not accurate enough to adapt the extent of pancreatectomy and have suggested routinely using frozen sectioning (FS) to evaluate the completeness of resection and also to check if ductal dilatation is active or passive, in order to avoid an excessive pancreatic resection. Separate main duct and branch duct analysis is needed due to the difference in the natural history of the disease. FS accuracy averages 95%. Eroded epithelium on the main duct, severe ductal inflammation mimicking dysplasia and reactive epithelial changes secondary to obstruction can lead to inappropriate FS results. FS results change the planned extent of resection in up to 30% of cases. The optimal cut-off leading to extend pancreatectomy is not consensual and our standard option is to extend pancreatectomy if FS reveals: (1) at least IPMN adenoma on the main duct; or (2) at least borderline IPMN on branch ducts; or (3) invasive carcinoma. However, the decision to extend resection must be taken after a multidisciplinary discussion since it does not exclusively depend on the FS result but also on age, general condition and expected prognosis after resection. The main limitation of using FS is the existence of discontinuous ("skip") lesions which account for approximately 10% of IPMN in surgical series and can lead to reoperation in up to 8% of cases.     

Demonstration of microcystic disease of the pancreas by magnetic resonance cholangiopancreatography: Report of a case

A case of microcystic disease of the pancreas which was clearly demonstrated by magnetic resonance cholangiopancreatography (MRCP) is reported herein. Cystic dilatation of the pancreatic duct was recognized by computed tomography scanning and endoscopic retrograde cholangiopancreatography (ERCP). Furthermore, the existence of microcystic clusters surrounding the dilated pancreatic duct were clearly visualized by MRCP. These microcystic clusters were strongly suspected preoperatively of having caused dilatation of the major pancreatic duct. Based on these findings, a distal pancreatectomy was performed. The operative specimen showed no accumulation of mucin and no evident lesions in the dilated pancreatic duct, being inconsistent with the entity of a mucus-producing tumor. Pathological examination revealed that the inner parts of microcysts constituted columnar epithelium with mucus production and papillary growth. Thus, a final histological diagnosis of intraductal papillary adenoma with idiopathic pancreatic duct ectasia was confirmed. In conclusion, MRCP, being a less aggressive diagnostic procedure than ERCP, proved extremely useful for obtaining precise information on cystic lesions of the pancreas in this patient.     

Invasive carcinoma of the pancreas derived from intraductal papillary adenocarcinoma without mucin hypersecretion but with changes in the pancreatic duct on pancreatography

We present a case of invasive carcinoma of the pancreas derived from intraductal papillary adenocarcinoma without mucin hypersecretion in a 65-year-old man with a 45-year history of alcohol abuse and a 2-year follow-up of chronic pancreatitis. Two years previously, in May 1998, he was admitted for investigation of abdominal pain. Computed tomography (CT) showed diffuse dilation of the main pancreatic duct with atrophy of the pancreatic parenchyma. Endoscopic retrograde pancreatography (ERP) showed a diffusely dilated main pancreatic duct with irregular side branches in the head of the pancreas. Chronic alcoholic pancreatitis was diagnosed on the basis of the pancreatography findings. The patient was readmitted for investigation of progressive weight loss in August 2000. Serum CA19-9 levels were markedly elevated (750 U/ml) and CT showed enlargement of the head and body of the pancreas. ERP showed irregularity of the main pancreatic duct in the head of the pancreas, and the distal main pancreatic duct (which was dilated on initial ERP examination) was interrupted in the body of the pancreas. Suspected pancreatic carcinoma was diagnosed, and pylorus-preserving pancreatoduodenectomy was performed. Frozen section examination of the cut end of the pancreas revealed ductal carcinoma, and total pancreatoduodenectomy with portal vein resection was performed. Histologically, the resected tumor was diagnosed as an invasive carcinoma derived from intraductal papillary adenocarcinoma without mucin hypersecretion. We recommend observing changes in the pancreatic duct on pancreatography to diagnose invasive carcinoma of the pancreas derived from intraductal papillary adenocarcinoma in a resectable state. Received: February 6, 2002 / Accepted: June 10, 2002 Offprint requests to: S. Ariizumi     

Clinicopathological studies on pancreatic carcinoma in totally pancreatectomized cases--with special reference to its intrapancreatic development and the pancreatogram

Histological examination and pancreatography were performed on 31 totally pancreatectomized cases of pancreatic ductal carcinoma, which was divided into four types according to its growth pattern in the pancreas. Pancreatograms of the resected specimens were also classified according to histological findings. Pancreatic carcinoma of Type I (20 cases) was diffusely infiltrating carcinoma with scirrhous stroma which was particularly present between the lobules. The pancreatogram of this type showed constriction of the main pancreatic duct accompanied by dilatation of the distal pancreatic duct. Carcinoma of Type II (6 cases) was diffusely developing in or around the dilated main pancreatic duct or its branches. The pancreatogram of Type II demonstrated the irregularly dilated main pancreatic duct with absence of its branches. Type III (4 cases) was the localized carcinoma with medullary structure. The pancreatogram showed replacement and dilatation of pancreatic ducts without marked stenosis of the main pancreatic duct. Type IV (1 case) was intraductal protruding carcinoma which showed polypoid shadow defects in remarkably dilated pancreatic ducts. The results suggested that a total pancreatectomy should be applied mainly for pancreatic carcinomas of Type II.     

Invasive ductal adenocarcinoma of the pancreas may originate from the larger pancreatic duct: a study of 13 tumors less than 2 cm in diameter

Background/Purpose We aimed to elucidate the origin/primary site of invasive ductal adenocarcinoma of the pancreas, based on the distribution of intraductal carcinoma components. These components were identified by a mural elastic fiber cuff. Methods Thirteen specimens from patients with invasive ductal adenocarcinoma (microscopically, less than 2 cm in diameter) of the pancreas were studied histopathologically. Variants of invasive ductal adenocarcinoma and intraductal papillary-mucinous carcinoma were excluded. Results Intraductal carcinoma components of invasive ductal adenocarcinoma were found in 12 of the specimens 13 (92%), and were observed within the tumor mass and/or on its boundary, or outside the tumor mass. Intraductal components were characterized by low papillary projections lacking a fibrovascular core, with/without surrounding tubular structures, or by irregular stratification and pleomorphism of the epithelial cells. Invasive components mostly showed a tubular pattern with desmoplasia. The distribution of the intraductal components in the 12 specimens was as follows: in 9 (75%), they were in both the main pancreatic duct and large branch ducts; and in 3, they were in the smaller branch ducts only. Conclusions Invasive ductal adenocarcinomas of the pancreas may originate most frequently from the main pancreatic duct or larger branch ducts, while the smaller ducts are less often the site of cancer origin.     

Presentation, treatment and prognosis of intraductal papillary mucinous neoplasm

Intraductal papillary mucinous neoplasms (IPMNs) are rare tumours rising from the pancreatic duct epithelium. They are characterized by intraductal papillary growth and thick mucin secretion; mucin fills the Wirsung and/or branch pancreatic ducts and may cause ductal dilatation. IPMNs are classified into three types, according to the site of involvement: main duct type, branch duct type, and combined type. Most branch type IPMNs are benign, while the other two types are frequently malignant. Recent advances in diagnostic imaging have led to an increased frequency of diagnosis of IPMNs, but the clinical features of them can range broadly from benign, borderline, and malignant non-invasive to invasive lesions, and their management has not yet been clearly defined. The most of patients are asymptomatic. The possibility of malignancy is increased in cases which large mural nodules are presented. Presence of a large branch type IPMN and marked dilatation of the main duct indicate the existence of adenoma. Not infrequently, synchronous or metachronous malignancies may be developed in various organs. Endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasonography (EUS), intraductal ultrasonography, and magnetic resonance cholangiopancreatography (MRCP) are the most valuable imaging techniques for diagnosis of these lesions. Prognosis is excellent after complete resection of benign and non-invasive malignant IPMNs. Total pancreatectomy should be reserved for patients with resectable but extensive IPMN involving the whole pancreas; its benefits must be balanced against perioperative risks.     

Spleen-preserving laparoscopic distal pancreatectomy after division of the splenic vessels

A 37-year-old woman with a history of syncope was hospitalized with a diagnosis of hypoglycemia due to insulinoma. Computed tomography (CT) and magnetic resonance imaging revealed an enhanced solid mass, 1.5 cm in diameter, at the tail of the pancreas. Angiography via the splenic artery revealed a hypervascular mass. Because the tumor was located deep in the pancreatic parenchyma, laparoscopic distal pancreatectomy was performed. The pancreas was exposed by dissecting the greater omentum, and the tumor was located by intraoperative ultrasonography. After division of the splenic artery, the pancreas, main pancreatic duct, and splenic vein were transected with an endoscopic linear stapler. The pancreatic pedicle was divided at the splenic hilum to preserve the spleen. The postoperative course was uneventful except for the appearance of splenic infarction on a CT scan 2 weeks after surgery but without any overt symptoms. Spleen-preserving laparoscopic distal pancreatectomy by division of splenic vessels is a feasible treatment option for benign pancreatic disease.     

Ductal carcinoma of the pancreas. Rationales for total pancreatectomy.

In order to evaluate total pancreatectomy as a surgical procedure for ductal carcinoma of the pancreas, a histopathological analysis was made on 18 resected specimens with special regard to the pattern of cancer growth in the pancreatic tissue. In five of them there was no lymphatic involvement or extrapancreatic invasion, but cancer extended continuously to the tail along with the pancreatic ducts and reached the end of the ducts in three cases. All 11 patients treated with Whipple's procedure died of recurrence, while of four total pancreatectomized patients, one with continuously invasive cancer to the end of the pancreatic duct has been living more than eight years postoperatively. We believe that total pancreatectomy for this type of "intraductal spreading cancer" without invasion beyond the pancreas is indicated as a radical procedure.     

Intraductal papillary mucinous neoplasm of the pancreas: clinical characteristics and treatment outcomes of 118 consecutive patients from a single center

Background/Purpose Appropriate surgical treatment strategies based on clinicopathological findings are unavailable for intraductal papillary mucinous neoplasm (IPMN) of the pancreas. We investigated the clinical features of pancreatic IPMN in a single-center database in order to design an optimal surgical strategy. Methods The medical records of 118 consecutive patients who had undergone surgical resection between August 1994 and December 2004, in whom IPMN was histologically confirmed, were reviewed retrospectively for radiological and pathological findings. Results Most of the invasive carcinomas in these patients were detected as the main-duct type (88.5%). The type of tumor (main-duct type vs branched-duct type), the tumor size, and the dilated duct size were significant predictive factors associated with malignancy. The relative risk of malignancy was greatest at 13-mm or more ductal dilation in the main-duct type (Odds ratio, 4.1), at 35-mm or more tumor size (Odds ratio, 7.6), and for main-duct type (Odds ratio, 3.9). Major pancreatic resections such as total pancreatectomy and pancreatoduodenectomy were performed in 14.5% and 69% of the patients, respectively. There was a 19.5% rate of incomplete resection, with these patients having a positive resection margin. However, significant recurrence did not occur in patients with a benign IPMN lesion which remained at the resection margin. The overall postoperative survival rate at 5 years was 98.2% for benign IPMN and 65.3% for malignant IPMN. Conclusions Function-preserving strategies, based on the clinical status of the patient, are necessary in order to avoid possible severe metabolic complications following extended pancreatectomy in patients with benign IPMN because of the low recurrence rate and good prognosis of this entity, irrespective of margin status.     

Repeated Pancreatectomy after Pancreatoduodenectomy

Background When pancreatic duct dilatation is found in the patient having undergone pancreatoduodenectomy (PD), observation is chosen in most cases. Similarly, recurrent tumor in the remnant pancreas of invasive ductal carcinoma (IDC) of the pancreas is seldom indicated for resection. We have aggressively performed repeated pancreatectomy for these cases and obtained good results. Methods Repeated pancreatectomy after PD was performed for three types of circumstances: (1) pancreatodigestive anastomotic stricture; (2) neoplasm after intraductal papillary mucinous neoplasm (IPMN); and (3) recurrence of IDC of the pancreas. Results Resection of anastomosis and reanastomosis was performed for pancreatodigestive stricture in four patients. Symptoms derived from pancreatitis in three patients resolved by the second operation and did not recur during follow-up. None of the four patients required pancreatic enzyme substitution because of clinically overt malabsorption, and the defecation frequency of the four patients was within twice a day. Mild diabetes mellitus has been identified in only one patient who had diabetes mellitus before the second surgery. Completion pancreatectomy and pancreatic tail resection was performed for recurrence in two patients and IDC in one patient, respectively, after PD for IPMN. Intrapancreatic recurrences of IPMN in two patients existed in the main pancreatic ducts. As CT revealed pancreatic duct dilatation but not intraductal tumors, recurrences were not correctly diagnosed before the second operation. Completion pancreatectomy was performed for recurrence of IDC in two patients. One patient who underwent completion pancreatectomy for recurrence of IDC survived 66/44 months after the first/second operation. Conclusion Repeated pancreatectomy should be performed for patients with pancreatodigestive anastomotic stricture to preserve remnant pancreatic function and for patients with neoplasm or pancreatic duct dilatation after PD for IPMN, and repeated pancreatectomy for recurrence of IDC might be indicated for selected patients.     

Surgical management of intraductal papillary mucinous tumors of the pancreas: the role of routine frozen section of the surgical margin, intraoperative endoscopic staged biopsies of the Wirsung duct, and pancreaticogastric anastomosis.

HYPOTHESIS: Resection of intraductal papillary mucinous tumors of the pancreas (IPMTP) should be tailored to longitudinal spreading into the pancreatic ductal system and the presence of malignant transformation. OBJECTIVE: To review a single institutional experience with IPMTP, focusing on the operative strategy of tailoring resection to the extent of disease. DESIGN: Retrospective study. SETTING: Academic tertiary referral center. PATIENTS: Thirteen patients with IPMTP were referred for resection during the past 10 years. Malignant growth was present in 7 patients (54%). According to the determination of tumor extent, distal pancreatic resection was performed in 3 patients, pancreatoduodenectomy was done in 9 patients, and total pancreatectomy was performed in 1 patient. The median follow-up time in this series was 46 months (range, 3-104 months). MAIN OUTCOME MEASURES: Preoperative and perioperative diagnosis, final pathologic results, and long-term outcome. RESULTS: A correct preoperative or perioperative diagnosis of IPMTP was achieved in 9 patients (69%). Routine frozen section of the surgical margin was used in all patients, changing the operative strategy in 3 (23%) of 13 patients by extending resection or leading to total pancreatectomy in 2 patients and 1 patient, respectively. A perioperative endoscopic examination of the Wirsung duct was performed in 3 patients with a correct preoperative or perioperative diagnosis of IPMTP and a dilated pancreatic duct. This allowed the examination of the entire pancreatic ductal system and staged intraductal biopsies, changing the operative strategy in 1 of these patients. Finally, after pancreatoduodenectomy, pancreaticogastric anastomosis was constructed in 5 patients, allowing endoscopic assessment of the pancreatic stump during long-term follow-up. The 5-year actuarial survival rate was 56.8% in the whole series. All patients with benign or microinvasive malignant disease remained disease-free, whereas all patients with invasive malignant disease died of tumor recurrence. CONCLUSIONS: Accurate determination of the extent of ductal disease and residual malignant growth, when present, is critical during surgical exploration to achieve radical resection and cure. Operative strategy should be based on routine frozen section of the surgical margin and perioperative endoscopic examination of the Wirsung duct with staged intraductal biopsies when technically feasible. The routine use of pancreaticogastric anastomosis after pancreatoduodenectomy allows easy, safe, and efficient long-term endoscopic assessment of the pancreatic stump.     

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.     

Enteric duplication cyst of the pancreas with duplicated pancreatic duct

Enteric duplication cyst is one of the rarest forms of cystic lesion of the pancreas. We report a unique case of an enteric duplication cyst of the pancreas that was communicating with a duplicated pancreatic duct. A 7-year-old girl with severe acute abdominal pain was found to have a large cyst that was smoothly communicating with the dilated pancreatic duct in the pancreatic tail. Analysis of cyst fluid showed elevated levels of amylase, carcinoembryonic antigen (CEA) and CA 19-9, and no epithelial cells. Intraoperative cyst pancreatography revealed that the pancreatic duct was duplicated in the tail: 1 duct was communicating with the cyst, and the other was dilated within the pancreatic tail. The patient underwent spleen-preserving distal pancreatectomy and complete cyst excision without complication. Because preoperative diagnosis of duplication cyst of the pancreas is difficult, this condition should be considered during differential diagnosis of atypical cystic lesions of the pancreas. Complete excision is desirable for the management of duplication cyst of the pancreas.     

Management of left pancreatic trauma

Left pancreatic traumas (LPTs) are rare but serious lesions occurring in 1 to 6 per cent of abdominal trauma patients and mainly resulting from blunt traumas. LPT severity is primarily dependent on the associated injuries and secondarily related to main pancreatic duct injury responsible for complications: acute pancreatitis, pseudocysts, pancreatic fistulas, or abscesses. The guidelines for blunt LPT management can be presented as follows. In case of emergency laparotomy, pancreas exploration is mandatory to detect pancreatic duct lesions. In the absence of main pancreatic duct lesions, simple drainage is advocated. In case of distal injury to the main pancreatic duct, a left pancreatectomy is mandatory. In the absence of initial laparotomy, the diagnosis is more and more based on CT and magnetic resonance cholangiopancreatography, which tend to replace endoscopic retrograde cholangiopancreatography (ERCP) as a first-intent diagnostic modality. In case of distal injury to the main pancreatic duct, spleen-preserving distal pancreatectomy is recommended. In the absence of main pancreatic duct lesions, nonoperative treatment is advocated. When LPTs are discovered at the time of complications, pancreatic fistulas and/or pseudocysts are associated with main pancreatic lesions, which can be treated by pancreatic duct stenting at ERCP and/or internal endoscopic cystogastrostomy. However, in such cases, spleen-preserving distal pancreatectomy remains the treatment of choice. Pancreatic ductal lesions resulting from LPT have to be diagnosed early to avoid late complications. Distal pancreatectomy remains the treatment of choice in case of severe pancreatic ductal lesions because the role of ERCP stenting and endoscopic techniques needs further evaluation.     

大鼠胰腺部分切除后导管细胞增殖规律研究

目的　探讨大鼠胰腺大部分切除术后残余胰腺组织导管上皮细胞增殖的时空规律 ,明确胰腺干细胞组织定位。方法　手术切除大鼠胰腺 90 %组织 ,不同时间点处死动物后取材 ,免疫组织化学染色 ,5 溴脱氧嘧啶核苷 (BrdU )标记 ,观察不同分类胰腺导管上皮细胞以及腺泡细胞着色并计算染色指数。结果　建模后第 1天主胰管、大胰管、小胰管细胞均出现增殖高峰 ,其中小胰管增殖持续到大鼠建模后第 5天 ,与对照组比较差异有非常显著性 (P <0 .0 0 1) ;腺泡细胞仅在建模后第 5天出现小的增殖峰 ;建模后第 7天破坏的小叶结构基本恢复 ,胰腺导管周围有新生胰岛形成。结论　大鼠胰腺大部分切除后 ,胰腺再生过程中出现了胰腺干细胞增生与分化 ,而且胰腺干细胞主要位于导管上皮细胞中。     

Cystic tumors of the pancreas. New clinical, radiologic, and pathologic observations in 67 patients.

Within a 12-year period we treated 67 patients (49 women, 18 men; mean age, 61 years) with cystic neoplasms of the pancreas, including 18 serous cystic adenomas, 15 benign mucinous cystic neoplasms, 27 mucinous cystadenocarcinomas, 3 papillary cystic tumors, 2 cystic islet cell tumors, and 2 cases of mucinous ductal ectasia. Mean tumor size was 6 cm (2 to 16 cm). In 39% the patients had no symptoms, and in 37% the lesions had been misdiagnosed as a pseudocyst. Computed tomography was useful for detection, for distinguishing the microcystic subgroup of serous cystadenoma, and for showing rim calcification (all 7 cases were malignant) but was not reliable for distinguishing neoplasm from pseudocyst, serous from mucinous tumors, or benign from malignant. Arteriography showed hypervascularity in 4 of 10 serous adenomas, 3 of 11 mucinous carcinomas, and 1 of 1 papillary cystic tumors. Endoscopic pancreatography showed no communication with the cyst cavity in 37 of 37 cases of cystic neoplasms but opacified the ectatic ducts in 2 of 2 cases of mucinous ductal ectasia. Stenosis or obstruction of the pancreatic duct indicated cancer. The tumor was resected by distal pancreatectomy in 25 patients, by proximal resection in 29, and by total pancreatectomy in one, with no operative deaths. Forty-four per cent of the tumors were malignant. In 10 cases the tumor was unresectable because of local extension or distant metastases, and those patients died at a mean of 4 months. Seventy-five per cent of those resected for cure are alive without evident recurrence. Because the epithelial lining of the tumor was partially (5% to 98%) absent in 40% to 72% of cases of the major tumor types, and the mucinous component comprised only about 65% of mucinous cystadenoma lining, misdiagnoses on frozen and even permanent sections were made. Mitoses and histologic solid growth correlated with malignancy. Neuroendocrine elements were seen in 87% of benign and 47% of malignant mucinous tumors. It is recommended that the terms macrocystic and microcystic be abandoned in favor of the histologic designations serous and mucinous. Incomplete examination of the cyst wall can be misleading, however. It is suggested that mucinous ductal ectasia be recognized separately from cystic tumors and that all of these lesions be resected, with the possible exception of asymptomatic confirmed serous cystadenomas.     

Characterization of K-ras gene mutations in association with mucinous hypersecretion in intraductal papillary-mucinous neoplasms

Background/Purpose Intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas have a favorable prognosis. However, invasive ductal carcinomas of the pancreas show a rapid progression. The aim of this study was to investigate gene mutations in pure pancreatic juice from IPMN patients and to define these genetic mutations in relation to the histopathological and clinical features of IPMNs. Methods Twenty-two patients with IPMN, 21 patients with ductal carcinoma, and 20 patients with normal pancreas or chronic pancreatitis were recruited for this study. We measured the main pancreatic duct’s largest diameter and the maximum size of a dilated branch was assessed by ultrasonography or endoscopic ultrasonography. Pure pancreatic juice was collected and was investigated for K-ras, p16, and p53 mutations. Results Mutant K-ras gene was detected in 13 of the 22 patients (59.1%) with IPMNs. Different kinds of mutations were detected in the same patient in 4 cases. In the 13 patients with mutant K-ras gene, the diameter of the most dilated part of the main pancreatic duct was 2–8 mm (average, 4.5 mm) and in 7 patients with wild-type K-ras gene, the diameter was 2–5 mm (average, 2.7 mm). There was a significant difference in the diameter of the main pancreatic duct between patients with and without the mutant K-ras gene (P = 0.0323). Conclusions The incidence of K-ras mutation may be associated with the hypersecretion of mucin.