The 2012 consensus guidelines lowered the threshold of the main duct caliber to 6mm without jeopardizing specificity while increasing sensitivity of diagnosis of main duct(MD-) IPMN. To stratify the malignant risk of branch duct(BD-) IPMNs more effectively "high-risk stigmata" and "worrisome features" have been defined. Indication for resection of BD-IPMN has become more conservative, excluding the size criterion. Since Japanese investigators recommend twice-a-year imaging studies of all BD-IPMNs to detect concomitant pancreatic carcinoma, lengthening of the surveillance interval after two years of no change remains controversial. IPMNs with strong suspicion of invasive or noninvasive carcinoma are an indication for standard pancreatectomy with lymph node dissection, while nonanatomical, limited pancreatectomy may be considered in those without malignant stigmata. Histological types of invasive IPMNs (colloid or tubular) and subtypes of IPMNs (gastric, intestinal, pancreatobiliary, or oncocytic) predict prognosis of the patients. Frozen section histology of the pancreatic margin is mandatory during resection of IPMN and high-grade dysplasia or invasive carcinoma requires additional resection. After resection, even patients with low-grade dysplasia need twice-a-year surveillance in view of the relatively high incidence of concomitant carcinoma, while those with invasive IPMN and high-grade dysplasia need surveillance with shorter intervals.

View full abstract

The international consensus guidelines for management of IPMN and MCN of the pancreas established in 2006 have been revised in 2012. The new description about the diagnosis in the revised version included work-up for cystic lesions of the pancreas, distinction of BD-IPMN from MCN and other pancreatic cysts, roles of cyst fluid analysis and cytology obtained by EUS-FNA in the diagnosis of cystic lesions of the pancreas, and distinction of BD-IPMN from serous cystic neoplasm (SCN). In addition, the algorithm for the management of suspected BD-IPMN was changed according to the recent information and current understandings since 2006 and typical clinical and imaging features of common pancreatic cysts were also presented.

View full abstract

International consensus guidelines 2012 for the management of IPMN and MCN was published from International Pancreatology Working Group (Chairman: Professor Masao Tanaka). This is composed of 8 chapters; Introduction, Classification, Investigation, Indications for resection, Methods of resection and other treatments, Histological aspects, Methods of follow-up and Conclusions. A brief review of Chapter 4: Indications for resection of IPMN is presented and remaining problems are discussed. Main discussions are as follows;
1. The definition of MD-IPMN and BD-IPMN was controversial and the definition of MD-IPMN, BD-IPMN and Mixed type IPMN has been newly proposed in International Consensus Guidelines 2012.
2. In algorithm of treatment for BD-IPMN, "high-risk stigmata" has been changed and "worrisome features" have been newly added. In the treatment of BD-IPMN of 2-3cm in size or of >3cm, surgical rejection is recommended or strongly recommended. This strategy may be different in Japan.

View full abstract

Invasive carcinoma derived from IPMN appears as colloid carcinoma or tubular adenocarcinoma. In general, colloid carcinoma shows a better prognosis compared to tubular adenocarcinoma. Therefore, the histological type of carcinoma should be included as part of the pathological report of IPMN. As the pathological definition of minimally invasive carcinoma derived from IPMN is not clear at the present time, the actual value of the distance from the pancreatic duct should be used. The morphological type of IPMN is useful for detecting the prognosis. The role of intraoperative frozen sections is important for determining the surgical margin. When the diagnosis of high grade or invasive carcinoma is made, additional resection should be performed. In specimen processing, the identification of the main pancreatic duct is critical, especially for distinguishing between BD-IPMN and MD-IPMN. Finally, the recognition of the definition of carcinoma derived from IPMN and carcinoma concomitant with IPMN is also important.

View full abstract

The management of BD-IPMN changed to more deliberate observation in the revised guidelines, and the occurrence of pancreatic ductal adenocarcinoma (PDAC) concomitant with BD-IPMN was documented. Therefore, careful attention should be paid to not only disease progression, but also the development of PDAC during follow-up.
In the revised guidelines for surveillance, EUS and/or MRI every 3-6 months for size dependent are recommended. Frequencies of progression and malignant transformation in the BD-IPMNs without any sign of malignancy have been reported only at 0-17.8% and 0-2.6%, respectively. Therefore annual surveillance is adequate for disease progression. However, for early detection of PDAC shorter interval and rich modality surveillance may be necessary.
We propose a prospective study for surveillance of BD-IPMN based of a follow-up every 6 months by dynamic CT or MRCP with EUS alternately. Elucidation of the natural history for IPMN and early detection of PDAC is expected.

View full abstract

In the international consensus guidelines 2012 for the management of IPMN and MCN of the pancreas, six histological aspects are discussed, (1) Types of invasive carcinoma of malignant IPMN, (2) Pathologic definition of minimally invasive carcinoma derived from IPMN, (3) Distinction and clinical relevance of gastric, intestinal, pancreatobiliary, and oncocytic forms of IPMNs, (4) Role of intraoperative frozen section evaluation in the surgical management of IPMNs, (5) Special instructions for specimen processing to differentiate BD-IPMN from MD-IPMN, (6) Distinction of carcinoma derived from and concomitant with an IPMN. According to these, there are two important points. One is a standardization of histopathological criteria of each pathologist, and the other is a standardization of pathological specimen-processing. It is necessary to approach to these aspects by cross-sectional effort.

View full abstract

To discuss the optimal excision method for intraductal papillary mucinous neoplasm of the pancreas (IPMN), it is necessary to better understand the pathology of this condition. Does the growth of IPMN occur even after infiltration? Cases of IPMN-derived invasive carcinoma have a fairly poor five-year survival rate of approximately 40%. IPMN can be curable if surgery is performed during the in situ carcinoma stage or earlier. Although unnecessary surgery should be avoided in cases where the cancer has not infiltrated and poses no threat to the life of its host, one must not allow lives to be lost to cancer because of waiting too long. Therefore, surgeons must exercise extreme caution and treat the cancer through both surgery and pre- and postoperative care and limiting mortalities due to surgical complications. In addition to the standard procedures of pancreaticoduodenectomy, pylorus-preserving pancreaticoduodenectomy and resection of the pancreatic body and tail with splenectomy, surgical procedures for IPMN includes segmental pancreatectomy, uncal resection, duodenum-preserving subtotal resection of the head of the pancreas, and spleen-preserving distal pancreatectomy with conservation of the splenic artery and vein.

View full abstract

The international consensus guidelines for management of intraductal papillary mucinous neoplasm (IPMN) and mucinous cystic neoplasm of the pancreas was first published in 2006 and was revised in 2012. Multi-institutional studies conducted by Japan Pancreas Society have propelled clarification of the clinical relationship between IPMN and invasive ductal adenocarcinoma. The newly discovered knowledge was incorporated into the revised international consensus guideline and the recommendations for surgery and methods of follow-up investigation in patients with branch-duct IPMN were modified accordingly. Pathohistoloical classification of IPMN subtypes was described and its clinical significance was emphasized. The natural history of IPMN will be further elucidated by future studies following to the revised guidelines. On the other hand, it is unclear whether or not the clinical management of IPMN can be practiced in accordance with the guideline recommendations in those countries with different health care systems. While it is important to create new evidences from domestic studies, it is requisite that the guideline be based on a truly international consensus.

View full abstract

We assessed the efficacy of enteric coated pancrelipase for digestive and absorption disorder in patients after pancreatoduodenectomy for pancreatic head carcinomas. For the clinically assessment of digestive disorder, we developed a new classification system based on clinical findings that include diarrhea, body weight, activity and symptoms of maldigestion. This classification consists of 6 grades which are matched to the Wong-Baker Faces Pain Rating Scale. Included in this study are seven cases that were administered pancreatin and converted to enteric coated pancrelipase. In one case, the administration of pancrelipase was stopped due to severe diarrhea. In the other 6 cases, digestive disorder significantly improved and these grades were 0 or 1. Our study suggests that enteric coated pancrelipase is more effective than pancreatin for digestive and absorption disorder after pancreatoduodenectomy for pancreatic head carcinomas. The new clinical classification is also useful to more precisely assess general digestive disorder.

View full abstract

Introduction: Performing pancreaticoduodenectomy (PD) to obese patients is more challenging and hazardous. Among the complications after PD, postoperative pancreatic fistula (POPF) is a persistent and life threatening problem. In this study, we investigated the specific impact of obesity on POPF after PD.
Materials & Methods: A retrospective analysis was conducted on 58 consecutive patients undergoing PD, with measurable fat volume, from July 2007 to March 2010. Volumetric measurement of abdominal visceral and subcutaneous fat tissue was performed by computed tomography. Intraoperative and perioperative data were collected, and the relationship between surgical outcome and obesity was investigated.
Results: Among 58 patients, 14 patients developed POPF (24%). Concerning obesity, subcutaneous fat area, visceral fat area, body weight and BMI were significantly higher in the patients with POPF than those in the patients without POPF. In the patients with POPF, operation time is longer than in the patients without POPF, but the difference was not significant. Intraoperative blood loss, and intraoperative blood transfusion is larger in the patients with POPF, but the difference was not significant.
Conclusion: Patients with POPF were more obese, and therefore, obesity may be a risk factor for POPF after PD.

View full abstract

A 77 year-old man had been successfully treated for a liver abscess by percutaneous drainage. Although there was no pancreatic lesion at that time, a pancreatic head tumor was discovered two months later. Computed tomography showed a 4-cm low-density area in the uncus of the pancreas, and endoscopic ultrasonography showed a small cystic component inside the tumor. Diffusion weighted magnetic resonance imaging indicated suppression of diffusion in the tumor. A pancreatoduodenectomy was performed and a partial gastrectomy was added for the incidentally found early gastric cancer. Histopathological examination confirmed the pancreatic tumor was adenosquamous carcinoma. The images, retrospectively, showed the tumor rapidly increased in size in merely two months, which could indicate the distinctive characteristics of the adenosquamous carcinoma.

View full abstract

Two cases of pancreatobiliary fistulas caused by intraductal papillary-mucinous pancreatic neoplasms (IPMNs), for which two different operations were performed, are reported. Case 1 was an 80-year-old female admitted to the hospital with fever and jaundice. Since she had tachycardia-related heart failure preoperatively, she was not considered a candidate for a curative operation, and palliative hepaticojejunostomy was performed instead. A pancreatogastric fistula developed 4 months after surgery, and the patient died 8 months postoperatively. Autopsy findings revealed moderately dysplastic, intraductal papillary-mucinous adenoma, as well as pancreato-gastric and -jejunal fistulas. Case 2 was a 70-year-old female admitted to the hospital with jaundice. Since curative operation seemed feasible, a total pancreatectomy was performed. Pathological findings revealed intraductal papillary-mucinous carcinoma. The patient is still alive 9 months postoperatively. In patients with a pancreatobiliary fistula caused by IPMN, appropriate surgery should be performed as early as possible.

View full abstract