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

BackgroundIntraductal papillary mucinous tumours (IPMT) were described as a distinct entity in l982.The extent of surgical resection remains controversial.MethodsSix patients with a diffuse dilatation of the main pancreatic duct were treated with total pancreatectomy for cure of IPMT.ResultsHistological 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.DiscussionIPMTs 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.     

Clinicopathologic features and outcomes of intraductal papillary-mucinous tumors of the pancreas

BACKGROUND/AIMS: The authors reviewed their experience with resected IPMT (intraductal papillary-mucinous tumor) of the pancreas to clarify the characteristics and prognosis of this neoplasm. METHODOLOGY: Between 1983 and 1998, 30 consecutive patients with IPMT underwent operations at our institution. Their clinicopathological features and postoperative long-term outcomes were analyzed retrospectively. RESULTS: There were 22 males and 8 females, with a mean age of 64 years. Operations performed were duodenum-preserving pancreatic head resection in 12 patients, distal pancreatectomy in 8, segmental pancreatectomy in 6, conventional pancreaticoduodenectomy in 4. Malignancy was found in 10 of 30 (33%). Factors significantly associated with malignancy were tumor size or presence in main pancreatic duct. In 30 resected patients after a mean follow-up of 60 months, tumor recurrence had occurred in 2 cases of invasive carcinoma that infiltrated into the extrapancreatic organ. The overall actuarial 5-year and 10-year survival was 83% and 62%, respectively. CONCLUSIONS: IPMT has a favorable prognosis after adequate resection. Despite slow growth, IPMT has an obvious malignant potential and a poor prognosis when invasive carcinoma has developed. Early recognition and pancreatectomy is the mainstay of treatment for IPMT.     

不同病理类型的胰腺导管内乳头状黏液性肿瘤的临床特征

目的 总结不同病理类型胰腺导管内黏液性乳头状瘤(IPMT)的临床表现,提高对IPMT的诊治水平.方法 回顾分析1996年3月至2008年9月间经手术切除且病理证实的49例IPMT患者的临床表现、影像学特点及病理学特征,比较分析良性、交界性、恶性IPMT的临床表现.结果 49例IPMT患者中男27例,女22例,平均年龄(58±11)岁.良性19例,交界性9例,恶性21例.3类IPMT患者在性别、发病年龄、烟酒史、胰腺炎发作史、糖尿病病史,是否存在腹痛、腰背部放射痛、腹胀、腹泻、消瘦等症状,血CEA、AST、ALT水平,肿瘤位置及肿瘤分型上的差异均无明显统计学意义.但黄疸、术前CA19-9和碱性磷酸酶水平、肿瘤直径、主胰管直径、囊性肿瘤内是否存在隔膜、附壁结节的大小等方面的差异有统计学意义.恶性IPMT术后5年有1例病死,1例复发;交界性和良性IPMT有1例复发,1例因其他疾病病死.结论 不同病理类型的IPMT 临床特征存在一些差异,需综合判断进行鉴别.     

Positron emission tomography with 2-deoxy-2-[<Superscript>18</Superscript>F] fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-glucose for diagnosis of intraductal papillary mucinous tumor of the pancreas with parenchymal invasion

We used positron emission tomography with 2-deoxy-2-[¹⁸F]fluoro-d-glucose (FDG-PET) in the diagnosis of two cases of malignant intraductal papillary mucinous tumor (IPMT) of the pancreas. A 56-year-old man and a 72-year-old man, both with tumors in the pancreatic head, were referred to Akita University Medical Center. Computed tomography revealed tumors with multiple cystic components in both patients. FDG-PET images showed markedly high FDG uptake in the area corresponding to a solid component found in one patient and diffuse faint uptake, higher than that of the surrounding tissue, in the other patient, who had no solid component. Histological examination of the resected specimens after pancreatectomy showed invasive carcinoma involving the pancreatic parenchyma in both patients. Although our experience is limited and preliminary, FDG-PET seems to be useful for the detection of malignancy in IPMT, especially in patients not showing any solid component on conventional diagnostic images such as computed tomography.     

Intraductal papillary-mucinous tumors of the pancreas: Clinicopathologic features, outcome, and nomenclature. Members of the Pancreas Clinic, and Pancreatic Surgeons of Mayo Clinic

BACKGROUND & AIMS: Intraductal papillary-mucinous tumor (IPMT) of the pancreatic ducts is increasingly recognized. This study investigated if clinical, imaging, or, histological features predicated outcome, formulated a treatment algorithm, and clarified relationships among IPMT, mucinous cystic neoplasms of the pancreas (MCN), and chronic pancreatitis. METHODS: The medical records, radiographs, and pathological specimens of 15 patients with IPMT (dilated main pancreatic duct or branch ducts with mucin overproduction) who were evaluated between October 1983 and January 1994 were reviewed. RESULTS: One patient had hepatic metastases. Fourteen underwent an operation (6 distal pancreatectomy, 4 total pancreatectomy, and 4 pancreaticoduodenectomy); all had dysplastic intraductal epithelium and chronic pancreatitis, whereas 3 had invasive adenocarcinoma. After a median of 25 months, 10 patients were alive; 3 of 4 with malignant and 2 of 11 with benign IPMT died (P < 0.05). Patients with or without carcinoma had similar clinical and radiographic features. A clinical diagnosis of chronic pancreatitis had been made in 9 patients with benign IMPT and in none with malignant IPMT (P < 0.05). CONCLUSIONS: IPMT is a dysplastic and likely precancerous lesion that is frequently diagnosed as chronic pancreatitis and is separate from MCN. Because it is not possible to distinguish noninvasive from invasive IPMT preoperatively, complete surgical excision of the dysplastic process is our treatment of choice whenever appropriate. (Gastroenterology 1996 Jun;110(6):1909-18)     

Prognosis of malignant intraductal papillary mucinous tumours of the pancreas after surgical resection. Comparison with pancreatic ductal adenocarcinoma

BACKGROUND: Although the prognosis in malignant resectable intraductal papillary mucinous tumours of the pancreas (IPMT) is often considered more favourable than for ordinary pancreatic ductal adenocarcinoma, the long term outcome remains ill defined. AIMS: To assess prognostic factors in patients with malignant IPMT after surgical resection, and to compare long term survival rates with those of patients surgically treated for ductal adenocarcinoma. METHODS: Seventy three patients underwent surgery for malignant IPMT in four French centres. Clinical, biochemical, and pathological features and follow up after resection were recorded. Patients with invasive malignant IPMT were matched with patients with pancreatic ductal adenocarcinoma, according to age and TNM stages; survival rates after resection were compared. RESULTS: Surgical treatment for IPMT were pancreaticoduodenectomy (n=46), distal (n=14), total (n=11), or segmentary (n=2) pancreatectomy. The operative mortality rate was 4%. IPMT corresponded to in situ (n=22) or invasive carcinoma (n=51). In the latter group, 17 had lymph node metastases. Overall median survival was 47 months. Five year survival rates in patients with in situ and invasive carcinoma were 88% and 36%, respectively. On univariate analysis, abdominal pain, preoperative high serum carbohydrate antigen 19.9 concentrations, caudal localisation, invasive carcinoma, lymph node metastases, peripancreatic extension, and malignant relapse were associated with a fatal outcome. Using multivariate analysis, lymph node metastases were the only prognostic factor (OR 7.5; 95% CI: 3.4 to 16.4). Overall five year survival rate was higher in patients with malignant invasive IPMT compared with those with pancreatic ductal carcinoma (36 v 21%, p=0.03), but was similar in the subset of stage II/III tumours. CONCLUSIONS: The prognosis of patients with resected in situ/invasive stage I malignant IPMT is excellent. In contrast, prognosis of locally advanced forms is as poor as in patients with pancreatic ductal adenocarcinoma.     

Cystic Lesions of the Pancreas

Opinion statement Pancreatic cystadenomas are a group of benign, premalignant, and malignant cystic tumors of the pancreas. Serous cystadenomas are benign lesions that often do not require surgical excision unless they are complicated by bleeding, obstruction, or pain. Mucinous cystadenomas are premalignant lesions that may be surgically excised if there is a concern regarding malignant degeneration. However, it may be difficult to predict the timing and risk of malignant change. Also, it is controversial whether all mucinous cystadenomas should be resected. Cystadenocarcinomas should be surgically managed if they are resectable, that is, there is no evidence of metastatic disease. Intraductal papillary mucinous tumors share many features with mucinous cystadenomas. However, intraductal papillary mucinous tumors arise from the pancreatic duct and are often associated with a dilated pancreatic duct. These lesions are often managed with surgical resection, including total pancreatectomy for diffuse lesions with evidence of localized malignancy.     

IDUS IN THE DIAGNOSIS OF IPMT

Intraductal papillary mucinous tumor of the pancreas (IPMT) is considered as having low‐grade malignant potential, and malignancy is not infrequent. Therefore, accurate diagnosis is indispensable for appropriate patient care. IPMT is classified mainly into two categories based on the distribution of tumor, the main duct type and the branch duct type. In the diagnosis of IPMT, there are four important points: differentiation of IPMT from other pancreatic pathologies; differentiation of malignancy from benign lesions; evaluation of tumor extent along the MPD; and investigation of duct cell carcinoma coexistent with or derived from IPMT. IPMT should be distinguished from chronic pancreatitis, ductal adenocarcinoma, or cystic neoplasms. IPMT often requires pancreaticoduodenectomy for cure, but such invasive surgery should be avoided in patients with benign hyperplasia. Mural nodules in the MPD can be clearly visualized by intraductal ultrasonography (IDUS). Measurement of the height of the tumor mass by IDUS is useful in distinguishing benign from malignant IPMT. Intraductal spread of IPMT along the MPD is demonstrated by IDUS as irregular thickening of the MPD wall. To achieve a tumor‐free margin in surgery, evaluation by IDUS of the extent of the tumor along the MPD is important. The expected accuracy of IDUS in the diagnosis of invasive IPMT is reportedly over 90%.     

Total pancreatectomy for intraductal papillary-mucinous tumor of the pancreas: reappraisal of total pancreatectomy

BACKGROUND/AIMS: Total pancreatectomy is rarely performed as the treatment of pancreatic carcinoma because of markedly impaired quality of life and poor prognosis. Intraductal papillary-mucinous tumor (IPMT) of the pancreas is characterized by extensive intraductal spread and favorable outcome even in its invasive stage. The role of total pancreatectomy was reappraised in the treatment of IPMT. METHODOLOGY: A total of five Japanese patients with IPMT underwent total pancreatectomy and their clinical follow-up data were reviewed. RESULTS: Total pancreatectomy was performed due to massive involvement of the entire pancreas in two patients, positive surgical margins on frozen section in one, benign IPMT with concomitant pancreatic cancers in one and recurrent IPMT in the remnant pancreas after distal pancreatectomy for IPMT in the other. Three of them underwent total pancreatectomy of the Whipple type, another underwent total gastrectomy and the other underwent the pylorus-preserving method. Surgical margins were negative by histology and no lymph node metastases were evident. Two patients had severe infection including liver abscess in one and pneumonia in the other. The former died on postoperative day 82 and the latter was controlled by medical treatment and discharged on postoperative day 73. The other three patients had an uneventful postoperative course and were discharged from 29 to 62 days after the operation. Long-term follow-up of the four patients revealed that three patients had hypoglycemic attacks, two diabetic retinopathy and two fatty liver. The four patients were doing well from 683 to 4,140 days after the operation without signs of recurrence. CONCLUSIONS: Total pancreatectomy would be indicated as a treatment of benign or malignant IPMT with extensive involvement when patients' condition permits and gives a chance of cure, although careful long-term medical care and follow-up are essential.     

Intraductal papillary mucinous tumor of the pancreas: computerized tomography and magnetic resonance imaging features

The aim of this study was to analyze the computerized tomography (CT) and magnetic resonance imaging (MRI) features of intraductal papillary mucinous tumor (IPMT) of the pancreas. The cases of eight patients with pathologically proven IPMT (1 papillary hyperplasia, 7 adenocarcinoma) of the pancreas were retrospectively reviewed. There were five men and three women with ages ranging from 42 to 82 years. Imaging studies included six thin-section dynamic CT scans, seven MRI scans, one MR cholangiopancreatography scan, and two endoscopic retrograde cholangiopancreatography scans. There was only one benign IPMT, which presented as a unilocular cyst in the pancreatic body with no mural nodules and no dilatation of the main pancreatic duct (MPD). All seven patients with malignant IPMT had multilocular cysts with papillary projections in the pancreatic head and/or uncinate process accompanied by dilated MPD (5 diffuse, 2 segmental). Communication between the cystic lesions and the MPD were evident in all seven patients. One patient had small mural nodules in the branch ducts of the pancreatic body and five had a bulging papilla with a patulous orifice. A mass effect resulting in biliary obstruction was shown in one patient. One patient had a ruptured cyst with mucin leakage into the right anterior pararenal space following sono-guided aspiration. In conclusion, the main imaging feature of IPMT in our patients was a multilocular cyst with papillary projections located in the pancreatic head and uncinate process. Although CT and MRI cannot differentiate mucin content from pancreatic juice, communication between the cystic lesion and the dilated MPD and a bulging papilla with a patulous orifice are characteristics of IPMT.     

Intraductal papillary-mucinous tumor of the pancreas: presentation in a young adult

Intraductal papillary-mucinous tumor (IPMT) of the pancreas is a premalignant lesion that can result in the hypersecretion of mucous and subsequent pancreatitis. In this report, one of the youngest cases of IPMT is described. Initial pancreaticogram was normal. Pathognomonic changes of the pancreatic duct were found only years later; otherwise, the recurrent pancreatitis seen in this patient might have been repeatedly misdiagnosed as idiopathic. Pre- and perioperative evaluation resulted in pancreaticoduodenectomy for what was felt to be a curative resection. However, the patient suffered an aggressive metastatic course. More extensive surgery may be needed in IPMT, such as total pancreatectomy, especially in cases of diffuse ductal dilation of the pancreas.     

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.     

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.     

Differential diagnosis of intraductal papillary‐mucinous tumor of the pancreas by endoscopic ultrasonography and intraductal ultrasonography

Background: Intraductal papillary‐mucinous tumor (IPMT) of the pancreas has a broad spectrum of histology ranging from hyperplasia to adenocarcinoma. Therefore, it is important to differentiate between the malignant and benign lesions to determine the therapeutic strategy for IPMT. Patients and Methods: Thirty‐nine patients with IPMT (27 men and 12 women, mean age: 63.3 years) underwent surgery between January 1985 and March 2002. The size of the cystic lesion, the maximum diameter of the main pancreatic duct (MPD), and the height of the papillary tumor inside the cyst were investigated by endoscopic ultrasonography (EUS) and/or intraductal ultrasonography (IDUS) before operation. These preoperative clinical findings were compared with the pathological findings of the resected specimen. Results: The size of the cystic lesion, the diameter of MPD, and the height of the papillary tumor in cases with malignant IPMT (invasive and non‐invasive carcinoma) were larger than those in cases with benign IPMT (adenoma and hyperplasia). Analysis of the images of the lesions revealed that the following three factors are important for diagnosing IPMT: (i) the size of the cystic lesion is ≥ 30 mm; (ii) the diameter of MPD is ≥ 8 mm; (iii) the height of the papillary tumor inside the cyst is ≥ 3 mm. It was not significant to differentiate between benign and malignant IPMT based on factor (i), but statistically significant (P < 0.001) based on factors (ii) and (iii). Conclusions: EUS and IDUS are useful in the differential diagnosis of IPMT, especially in the differentiation between malignant and benign IPMT.     

Intraductal papillary and mucinous pancreatic tumour: a new extracolonic tumour in familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is characterised by the development of numerous colorectal adenomatous polyps. Other extracolonic benign or malignant lesions have been reported previously in association with FAP but precancerous lesions in the pancreas have never been described. We report the first case of intraductal papillary and mucinous pancreatic tumour (IPMT) in a patient with FAP. A 48 year old man with a well documented past history of FAP was admitted for epigastric pain, weight loss, and new onset diabetes mellitus. Spiral computed tomography scan revealed a large tumour in the pancreatic head with upstream main pancreatic duct dilatation. Endoscopic ultrasonography confirmed these data. Mucous secretion was seen at duodenoscopy and a lesion in the main pancreatic duct was confirmed by retrograde pancreatography. The patient underwent a pancreaticoduodenectomy for suspected IPMT. Histological examination of the resected specimen confirmed an IPMT with in situ carcinoma. Twelve months after resection, the patient remained free of tumour relapse. Genetic analysis showed loss of the wild allele of the adenomatous polyposis coli gene in IPMT, causing inactivation of both alleles and demonstrating that IPMT was not incidental in this patient. IPMT should be included in the extracolonic localisation of FAP.     

Outcome after surgical resection of intraductal papillary and mucinous tumors of the pancreas

OBJECTIVE: Treatment of intraductal papillary and mucinous tumors of pancreas (IPMT) usually requires surgery. The objective of this study was to evaluate the risk of recurrence in patients after surgery according to the histological nature of the neoplasm and the type of surgery. METHODS: The outcome of 45 patients who underwent partial pancreatectomy (n = 35) or total pancreatectomy (n = 10) for IPMT was studied according to the nature of the neoplasm (invasive carcinoma or noninvasive neoplasm), type of surgery (partial or total pancreatectomy), and lymph nodes status. RESULTS: The overall 3-yr actuarial survival rate was 83%. Death occurred in seven of 20 (35%) patients with invasive carcinoma and in one of 26 (4%) patients with noninvasive tumors (p<0.05). There were two recurrences in the seven patients with noninvasive neoplasm who underwent partial pancreatectomy with involved resection margins, and none in the 13 patients with disease-free margins. In patients with invasive carcinoma, there was one recurrence after total pancreatectomy, six after partial pancreatectomy with disease-free margins and six after partial pancreatectomy with involved margins. In patients with invasive carcinoma, total pancreatectomy and the absence of lymph nodes involvement were independently associated with a low risk of recurrence. CONCLUSIONS: IPMT may be managed as follows: 1) in patients with noninvasive neoplasms, partial pancreatic resection should be guided by frozen section examination until disease-free margins are obtained; and 2) in patients with invasive carcinoma, total pancreatectomy seems most likely to cure the patient, but should be discussed according to the general status and the age.     

Mucinous cystadenocarcinomas of the pancreas

BACKGROUND/AIMS: The purpose of this study was to evaluate the clinicopathologic characteristics, diagnosis and treatment of mucinous cystadenocarcinomas (MCACs) of the pancreas. METHODOLOGY: This is a retrospective review of 6 patients who underwent curative resection for MCACs of the pancreas in the Department of General Endocrine and Transplantation Surgery, Medical University of Gdańsk from 1994-2004. Clinical presentation, radiological evaluation and surgical procedures were analyzed. RESULTS: There were 4 women and 2 men. Median age was 59 years. Patients complained of abdominal pain, nausea, vomiting and weigh loss, 2 of them had jaundice and 1 gastrointestinal (GI) bleeding. Ultrasonography and computed tomography showed cystic lesions. Solid component was found in 3 cases. Three endoscopic retrograde cholangiopancreatographys (ERCPs) were unhelpful in differentiating between malignant tumor and benign lesion. All patients underwent resection. In 3 cases Whipple resection, in 1 case Traverso - Longmire resection and in 2 cases distal pancreatectomy was performed. Histopathologically, all tumors were mucinous cystadenocarcinomas. CONCLUSIONS: Diagnostic accuracy for cystic pancreatic neoplasm is still limited. Surgical resection is recommended in all cystic tumors that are not clearly defined.     

Successful pre-operative diagnosis of malignant intraductal papillary mucinous tumor of the pancreas by detecting telomerase activity

Summary Background. Pre-operative differential diagnosis between and malignant intraductal papillary mucinous tumor (IPMT) of the pancreas is markedly difficult by imaging examination. In recent years, telomerase activity has been reported to be detected only in malignant tumors. Methods. A 52-yr-old man with abdominal pain was diagnosed with a IPMT through imaging examination. Telomerase activity of the pure pancreatic juice, which was obtained pre-operatively by endoscopic retrograde pancreatic juice aspiration (ERPJA), was analyzed by telomeric repeat amplification protocol (TRAP) assay. Results. Telomerase activity was detected in the pure pancreatic juice of the patient, who was diagnosed with a malignant IPMT. A pylorus-preserving pancreatoduodenectomy was performed, and subsequent pathological findings revealed the tumor to be adenocarcinoma in adenoma with papillary growth. Conclusion. Detection of telomerase activity of the pure pancreatic juice might be useful to distinguish benign from malignant IPMT pre-operatively.     

Intraductal papillary-mucinous tumor of the pancreas head with complete absence of the ventral pancreatic duct of Wirsung

A case of intraductal papillary mucinous tumor of the pancreas with complete absence of the ventral pancreatic duct of Wirsung is presented. A 74-year-old Japanese man was admitted to our hospital because of elevated serum amylase concentration. Abdominal computed tomography (CT) scanning revealed diffuse dilatation of the main pancreatic duct and a diffuse and uncircumscribed area with heterogeneous density in the pancreas head. Endoscopic retrograde cholangiopancreatography revealed that the main pancreatic duct was connected with an accessory papilla and was diffusely dilated, without any irregularity of the duct wall being observed in the entire length of the duct. The common bile duct was detected only by cannulation through Vater’s papilla, and no pancreatic duct or its communicating branch was found. Some branches, directed to the dorsal portion of the pancreas head, were found arising from the accessory pancreatic duct. Intraductal ultrasound examination performed through the accessory papilla and the common bile duct revealed a small tumor with a heterogeneous echo level in the pancreas head. From these findings, intraductal papillary-mucinous tumor (IPMT) occurring in the pancreas head was diagnosed, and pylorus-preserving pancreaticoduodenectomy was performed. The resected specimen revealed IPMT in the pancreas head. A roentgenographic study of the resected specimen revealed a defect caused by the tumor located in the pancreatic duct connected with the accessory papilla and showed that there was complete absence of the pancreatic duct connected with Vater’s papilla. Surgical resection enabled us to completely analyze the duct system of pancreas divisum. Although it is not known whether there is a relationship between the pathogenesis of IPMT and embryological anomaly of the pancreatic duct system, this case may provide an insight into the pathogenesis of IPMT.     

Cystic neoplasm of the pancreas: a Japanese multiinstitutional study of intraductal papillary mucinous tumor and mucinous cystic tumor

The Japan Pancreas Society performed a multiinstitutional, retrospective study of 1379 cases of intraductal papillary mucinous tumor (IPMT) and 179 cases of mucinous cystic tumor (MCT) of the pancreas. Clinicopathologic features and postoperative long-term outcomes were investigated. IPMT were most frequently found in men and in the head of the pancreas. In contrast, all patients with MCT were women. Ovarian-type stroma were found in only 42.2% of the MCT cases. Prognostic indicators of malignant IPMT included advanced age, positive symptoms, abundant mucous secretion, presence of large nodules and/or large cysts, remarkable dilatation of the main pancreatic duct, and main duct- or combined-type IPMT. Advanced age, positive symptoms, and presence of large nodules and/or large cysts were predictive of malignant MCT. The 5-year survival rate of IPMT patients was 98%-100% in adenoma to noninvasive carcinoma cases, 89% in minimally invasive carcinoma cases, and 57.7% in invasive carcinoma cases. The 5-year survival rate of MCT patients was 100% in adenoma to minimally invasive carcinoma cases and 37.5% in invasive carcinoma cases. In conclusion, IPMT and MCT show distinct clinicopathologic and prognostic differences. The results from this study may contribute to the diagnosis and treatment of IPMT and MCT.