Single-session endoscopic bilateral y-configured placement of metal stents for hilar malignant biliary obstruction.

BACKGROUND: The aim of this study was to evaluate the efficacy and safety of endoscopic bilateral biliary metal stent placement for hilar malignant obstruction. PATIENTS AND METHODS: Twenty patients with unresectable malignant hilar biliary obstruction who had undergone endoscopic bilateral Y-configured biliary drainage with metal stents were enrolled as a study group (YMS group). Thirty-seven patients who had undergone bilateral drainage with plastic stents were selected as a historical control (PS group). Two newly designed metal stents for bilateral Y-configured placement were endoscopically deployed in a partial stent-in-stent manner in one session. Technical success, early complications, and stent patency were evaluated. RESULTS: The technical success rate in the YMS group was 100%. Mild post-endoscopic retrograde cholangiopancreatography pancreatitis occurred in one patient in the YMS group and in two in the PS group. The success rate of biliary decompression was 95% in the YMS group and 89% in the PS group (P=0.65). During a median follow-up period of 7.3months, the incidence of stent occlusion in the YMS group was significantly lower than that in the PS group (30% vs 62%, P=0.028). Mean stent patency in the YMS group was 250days and that in the PS group was 115days (P=0.0061). Risk factors for stent occlusion were bile duct cancer (P=0.035) and the PS group (P=0.07) by multivariate analysis. CONCLUSION: Single-session endoscopic bilateral biliary placement of newly designed metal stents for hilar malignant obstruction is safe and useful with a high technical success rate and a long patency period.

Can pancreatic duct stenting prevent post-ERCP pancreatitis in patients who undergo pancreatic duct guidewire placement for achieving selective biliary cannulation? A prospective randomized controlled trial.

BACKGROUND: Although pancreatic duct guidewire placement (P-GW) for achieving selective biliary cannulation is reported to be effective in patients in whom endoscopic retrograde cholangiopancreatography (ERCP) is difficult, this technique entails a possible increased risk of post-ERCP pancreatitis. We conducted a prospective randomized controlled trial to evaluate the prophylactic effect of pancreatic duct stenting on the frequency of post-ERCP pancreatitis in patients who underwent P-GW. METHODS: Seventy patients who underwent P-GW for achieving selective biliary cannulation were included in this study. Patients were randomly assigned to either the stent group (n = 35) or the no-stent group (n = 35). The pancreatic duct stent used was a 5-Fr, 4-cm-long stent with a single pigtail at the duodenal end (Pit-stent™). The primary endpoint was the frequency of post-ERCP pancreatitis. RESULTS: Selective biliary cannulation was achieved in 80% of the stent group and in 94% of the no-stent group (P = 0.15). Post-ERCP pancreatitis occurred in 13% (9 patients; mild). Pancreatic duct stenting was successful in 91% of the stent group. One patient in the stent group developed migration of the stent during the procedure, followed by mild pancreatitis. The frequency of post-ERCP pancreatitis in the stent group was significantly lower than that in the no-stent group (2.9 vs. 23%, relative risk 0.13, confidence interval 0.016, 0.95). CONCLUSION: Pancreatic duct stenting after P-GW for achieving selective biliary cannulation is recommended to reduce the incidence of post-ERCP pancreatitis.

Diagnostic efficacy of the cell block method in comparison with smear cytology of tissue samples obtained by endoscopic ultrasound-guided fine-needle aspiration.

BACKGROUND: The diagnostic efficacy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) cytology may vary greatly depending on the treatment of the samples obtained and the level of proficiency of the cytopathologist or cytoscreener. METHODS: We prospectively evaluated the diagnostic efficacy of the cell block (CB) method and that of smear cytology using tissue samples obtained in the same needle pass at EUS-FNA in 33 patients with pancreatic tumors, abdominal tumors or swollen lymph nodes. An average of 3.1 passes were applied during the procedure without affirmation by rapid cytology. About half of the material obtained by each single pass was subjected to smear cytology, while the other half was evaluated by the CB method. Four to 12 glass slides were prepared for both Papanicolaou stain and Giemsa stain. The CB sections were prepared using the sodium alginate method and subjected to HE, PAS-AB and immunohistochemical stains. Two pathologists independently made cytological and histological diagnoses. The final diagnosis was based on integration of cytohistological findings, diagnostic imaging, and clinical course. RESULTS: The diagnostic accuracy of the CB method and that of smear cytology were 93.9 and 60.6%, respectively (p = 0.003), and their respective sensitivities were 92.0 and 60.0% (p = 0.02). It was easier to make a definite diagnosis of not only malignancies but also benign conditions by the CB method than by the smear method. CONCLUSION: The CB method with immunostaining showed a higher diagnostic yield than smear cytology in patients who had undergone EUS-FNA without rapid on-site cytology.

A case of distal bile duct cancer with extensive intraepithelial spread diagnosed preoperatively by peroral cholangioscopy combined with narrow band imaging.

A 75-year-old woman with jaundice was given a diagnosis of bile duct cancer using several imaging modalities. The proximal and middle bile ducts were evaluated as normal by multidetector-row CT and intraductal ultrasonography. However, peroral cholangioscopy (POCS) with narrow band imaging (NBI) clearly revealed the intraepithelial extent of the bile duct cancer from the distal bile duct to the hilar bile duct, which was confirmed by histological examination of the resected specimen. POCS combined with NBI is expected to be useful for determining the resection margin in bile duct cancer cases.

Endosonography-guided biliary drainage in cases with difficult transpapillary endoscopic biliary drainage.

BACKGROUND: Recently, reports on a new endoscopic biliary drainage technique utilizing endosonographic guidance (endosonography-guided biliary drainage [ESBD]) have been increasing. The aim of this study was to evaluate the efficacy of ESBD in cases with difficult transpapillary endoscopic biliary drainage (EBD). PATIENTS AND METHODS: Sixteen patients with obstructive jaundice who underwent ESBD because of difficult EBD between January 2007 and September 2008 were included. The technical success, complications, and clinical efficacy of ESBD were prospectively evaluated. RESULTS: ESBD was performed via the duodenum, stomach, and esophagus in eight, six and two patients, respectively. Stent placement was successful in all cases and excellent biliary decompression was achieved in all but one patient. One patient developed localized peritonitis following guidewire migration and re-puncture of the bile duct. In another patient, stent migration was observed one week after ESBD and re-ESBD was carried out. Three patients underwent surgery for their primary diseases, and stent exchange was carried out in 10 patients during the course. CONCLUSIONS: ESBD is an effective treatment for obstructive jaundice that will replace percutaneous transhepatic biliary drainage in cases of difficult EBD and is a possible alternative to EBD in selected cases.

Small pancreatic cancer with pancreas divisum preoperatively diagnosed by pancreatic juice cytology.

We present a case of small pancreatic head cancer with pancreas divisum preoperatively diagnosed by pancreatic juice cytology. A 60-year-old woman was referred to our hospital for evaluation of a dilated main pancreatic duct (MPD). A small and poorly reproducible low-echoic lesion in the pancreas was suspected by ultrasonography (US) and endoscopic ultrasonography (EUS). Magnetic resonance cholangiopancreatography (MRCP) failed to visualize the ventral pancreatic duct, and the upstream dorsal pancreatic duct was dilated. Endoscopic retrograde cholangiopancreatography (ERCP) was indicative of pancreas divisum, and complete obstruction of the MPD in the pancreatic head was seen. Cytology of pancreatic juice obtained from the dorsal pancreas after minor papilla sphincterotomy revealed the presence of adenocarcinoma cells. Pancreatoduodenectomy was performed under the diagnosis of pancreatic head cancer with pancreas divisum. Histological examination revealed moderately-differentiated tubular adenocarcinoma 20 mm in diameter, located in the pancreatic head. Dilatation of the dorsal pancreatic duct is sometimes observed in cases with pancreas divisum without the presence of tumors. When pancreatic duct stenosis also exists in such cases, even if a tumor is not clearly visualized by diagnostic imaging, vigorous examinations such as pancreatic juice cytology are recommended to establish an accurate diagnosis.

[A case of a small pancreatic cancer with an intact main pancreatic duct].

A 56-year-old woman was admitted to our department for further evaluation of a hypoechoic mass in the pancreatic head detected by abdominal ultrasonography during a medical check-up. Abdominal and endoscopic ultrasonography demonstrated a demarcated round hypoechoic mass 15 mm in size without dilation of the main pancreatic duct, and ERP showed a normal main pancreatic duct and branch duct. Because pancreatic cancer was strongly suspected based on dynamic CT and MRI findings, she underwent pancreatoduodenectomy. Pathologically, the tumor was diagnosed as well-differentiated adenocarcinoma in the pancreatic head, 13 mm in diameter, 10mm apart from the main pancreatic duct. The main pancreatic duct was completely free of cancer cells and the origin of the cancer was considered to be the epithelium of a peripheral branch duct.

Long intestinal tube insertion with the ropeway method facilitated by a guidewire placed by transnasal ultrathin endoscopy for bowel obstruction.

AIM: For patients with bowel obstruction, intestinal decompression by a long tube is recommended. We assessed the usefulness of a new technique for insertion of a long tube with a guidewire placed by transnasal ultrathin endoscopy. METHODS: Nineteen patients who had been diagnosed as suffering from bowel obstruction underwent long-tube insertion with the ropeway technique using a guidewire placed by transnasal endoscopy. Thirty-three patients who had undergone conventional insertion of a long tube were included as controls. The success rate of intubation of the small bowel and the time required for the procedure were compared between the subjects and controls. RESULTS: The success rate of intubation was 94.7% (18/19) in subjects and 84.8% (28/33) in controls (P = 0.53). The time required for insertion in the subjects and controls was 24.1 +/- 8.1 min and 48.7 +/- 25.3 min, respectively, with a statistically significant difference (P < 0.001). No complications relevant to the procedure were encountered in either of the groups. CONCLUSION: Long-tube insertion facilitated by transnasal endoscopy reduces the time required for insertion in comparison with the conventional technique without endoscopy. Endoscopy-assisted long-tube insertion with the ropeway method is a safe and useful procedure for decompression in patients with bowel obstruction.

Endosonography-guided gallbladder drainage for acute cholecystitis following covered metal stent deployment.

Endosonography-guided biliary drainage (ESBD) is gaining acceptance as an effective treatment for obstructive jaundice. Only a few reports on the application of this technique to the gallbladder (endosonography-guided gallbladder drainage [ESGBD]) have been published in the literature. In order to relieve acute cholecystitis which developed in a patient with unresectable malignant biliary obstruction after deployment of a covered metal stent (CMS), we applied this technique. ESGBD was carried out by using an electronic curved linear array echoendoscope. After visualization of the gallbladder and determination of the puncture route, a needle knife papillotome was advanced with electrocautery to pierce the gastric and gallbladder walls. Under the guidance of a guidewire inserted through the needle sheath into the gallbladder, a 7.2 Fr, 30 cm-long, single pigtail plastic tube was placed to bridge the gallbladder and the stomach. No complications relevant to the procedure were encountered. ESGBD was quite effective in ameliorating the patient's acute cholecystitis and the drainage tube was removed after 10 days without sequelae. Acute cholecystitis following CMS deployment is considered to be a good indication for ESGBD.

Snare-over-the-wire technique for safe exchange of a stent following endosonography-guided biliary drainage.

Endosonography-guided biliary drainage (ESBD) is a new option that allows establishment of biliary drainage. Due to the diameter of the working channel of an echoendoscope, it is necessary to replace a small caliber stent with a larger one to lessen the risk of stent occlusion. However, insertion of a guidewire into the bile duct via the hole of the sinus tract following direct removal of a previously placed stent is not always possible, resulting in guidewire passage outside the fistula and bile leakage. Cannulation of the previously deployed stent, guidewire insertion into the bile duct via the cannula and the stent, and removal of the stent with the snare over the guidewire leaving the guidewire in place (the snare-over-the-wire technique [SOW]) for stent exchange following ESBD was attempted. Four patients who required stent exchange following ESBD were included in the present study to evaluate the feasibility and usefulness of SOW. SOW was successful in all the cases. A new stent was also successfully deployed over the guidewire in all the cases. No complications were encountered. The snare-over-the-wire technique is feasible and useful in stent exchange following ESBD for the reduction of the risk of guidewire migration.

Long-tube insertion with the ropeway method facilitated by a guidewire placed by transnasal ultrathin endoscopy for bowel obstruction: a prospective, randomized, controlled trial.

BACKGROUND: It is often difficult to insert a long intestinal tube in the small bowel of patients with bowel obstruction, and it often results in long procedure time and severe patient distress. OBJECTIVE: To assess the usefulness of the ropeway method by using a guidewire placed with the assistance of transnasal ultrathin endoscopy in long-tube insertion for patients with bowel obstruction. DESIGN: Prospective, randomized, controlled, single-center study. PATIENTS AND INTERVENTIONS: Thirty-four consecutive patients with bowel obstruction requiring decompression participated in the study and were randomized to the insertion of a long tube with the ropeway method (ILTR) group (ie, insertion along an endoscopically placed guidewire that was passed through only the distal 4 cm of the tube) or insertion by a conventional method group (C group). MAIN OUTCOME MEASUREMENTS: The time required for the procedure (main), success rate, x-ray exposure time, and intensity of patient distress measured with a visual analog scale of 1 to 5 (better to worse). RESULTS: The mean (+/- standard deviation) duration of the procedure in the successful cases in the ILTR group and the C group was 16.1 +/- 5.6 minutes and 26.4 +/- 13.8 minutes, respectively (P = .010). The success rate was 100% in the ILTR group and 88% in the C group (P = .48). The mean (+/- standard deviation) x-ray exposure time and intensity of patient distress were, respectively, 16.4 +/- 8.7 minutes and 33.2 +/- 12.3 minutes (P < .001) and 2.6 +/- 0.7 and 3.7 +/- 1.2 (P = .016). LIMITATIONS: Single-center study and small sample size to evaluate overall safety. CONCLUSIONS: Long-tube insertion for bowel obstruction with the ropeway method facilitated by transnasal ultrathin endoscopy was superior to conventional fluoroscopic placement with regard to overall procedure success, time required, and patient comfort.

Impact of a transparent hood on the performance of total colonoscopy: a randomized controlled trial.

BACKGROUND: Clinical demand for total colonoscopy (TCS) is increasing. Improvement of the cecal intubation rate and shortening of the examination time would expand the capacity for TCS. OBJECTIVE: To assess the efficacy of a transparent hood attached to the tip of a colonoscope for cecal intubation in TCS. DESIGN: Prospective, randomized, controlled study. SETTING: Single tertiary-referral center. INTERVENTIONS: TCS. MAIN OUTCOME MEASUREMENTS: Cecal intubation time and rate, complications, patient discomfort, and detection rate of colonic polyps. METHODS: Patients who were to undergo screening and/or surveillance TCS for colorectal cancer were invited to participate in the study. Cecal intubation time and rate, complications, patient discomfort, and detection rate of colonic polyps were evaluated. RESULTS: A total of 592 patients enrolled in this study were randomly allocated to the hood group and no-hood group. The mean (SD) cecal intubation time in the hood group and the no-hood group was 10.2 +/- 12.5 minutes and 13.4 +/- 15.8 minutes, respectively (P = .0241). The effect of its use was more prominent in the expert endoscopists group compared with those with moderate experience. The cecal intubation rate and the detection rate of small polyps in the 2 groups were similar. The grade of patient discomfort was significantly lower in the hood group. No complications were encountered with the use of the hood. CONCLUSIONS: Use of a transparent hood on the tip of a colonoscope shortened the time required for cecal intubation and decreased patient discomfort; such use was more effective among experts in shortening the examination time.

Therapeutic endoscopic retrograde cholangiopancreatography using an anterior oblique-viewing endoscope for bile duct stones in patients with prior Billroth II gastrectomy.

BACKGROUND: Prior Billroth II gastrectomy is an important factor presenting difficulties in endoscopic retrograde cholangiopancreatography (ERCP) administration. We retrospectively evaluated the usefulness and safety of therapeutic ERCP using an anterior oblique-viewing endoscope for bile duct stones in patients with prior Billroth II gastrectomy. METHODS: Forty-three patients with bile duct stones after Billroth II gastrectomy who underwent ERCP from January 1998 to February 2008 were enrolled in this study. We used anterior oblique-viewing endoscopes for all procedures. Endoscopic sphincterotomy was performed using a needle knife guided by a biliary stent. A total of 808 patients without gastrectomy who had undergone ERCP for bile duct stones in the same period were reviewed as controls. RESULTS: The success rate of access to the papilla of Vater was 88.4%, and the average time required for such access was 13 min. In cases of successful access, selective cannulation of the bile duct and complete stone removal were achieved in 94.7% and 94.6% of patients, respectively. The incidence of complications was 4.7%. As for the success rate of selective cannulation, complete stone removal ratio, and the incidence of complications, there were no significant differences compared with the control group. CONCLUSIONS: Use of an anterior oblique-viewing endoscope enables good success rates in selective cannulation and complete stone removal to be achieved in patients with prior Billroth II gastrectomy. The safety of therapeutic ERCP for removal of bile duct stones in those patients is comparable to that in patients with normal anatomy.

Pancreatic guidewire placement for achieving selective biliary cannulation during endoscopic retrograde cholangio-pancreatography.

AIM: To investigate the frequency and risk factors for acute pancreatitis after pancreatic guidewire placement (P-GW) in achieving cannulation of the bile duct during endoscopic retrograde cholangio-pancreatography (ERCP). METHODS: P-GW was performed in 113 patients in whom cannulation of the bile duct was difficult. The success rate of biliary cannulation, the frequency and risk factors of post-ERCP pancreatitis, and the frequency of spontaneous migration of the pancreatic duct stent were investigated. RESULTS: Selective biliary cannulation with P-GW was achieved in 73% of the patients. Post-ERCP pancreatitis occurred in 12% (14 patients: mild, 13; moderate, 1). Prophylactic pancreatic stenting was attempted in 59% of the patients. Of the 64 patients who successfully underwent stent placement, three developed mild pancreatitis (4.7%). Of the 49 patients without stent placement, 11 developed pancreatitis (22%: mild, 10; moderate, 1). Of the five patients in whom stent placement was unsuccessful, two developed mild pancreatitis. Univariate and multivariate analyses revealed no pancreatic stenting to be the only significant risk factor for pancreatitis. Spontaneous migration of the stent was observed within two weeks in 92% of the patients who had undergone pancreatic duct stenting. CONCLUSION: P-GW is useful for achieving selective biliary cannulation. Pancreatic duct stenting after P-GW can reduce the incidence of post-ERCP pancreatitis, which requires evaluation by means of prospective randomized controlled trials.

Temporary endosonography-guided biliary drainage for transgastrointestinal deployment of a self-expandable metallic stent.

Endosonography-guided biliary drainage (ESBD) is now gaining acceptance as a useful alternative for the management of obstructive jaundice.(1) At present, ESBD is used mainly to establish an anastomosis between the biliary tree and the duodenum, stomach, jejunum, or esophagus by placing a stent so as to bridge the bile duct and alimentary tract. We herein report a new application of ESBD, that is, its temporary use for gaining access to the bile duct in order to deploy a self-expandable metallic stent (SEMS) via the transhepatic route. In a patient with pylorus stenosis due to advanced gastric cancer with extrahepatic bile duct obstruction caused by nodal metastasis, a plastic stent was placed temporarily by ESBD to bridge the esophagus and the left hepatic duct. Ten days later, the stent was retrieved, leaving a guidewire in the bile duct, and a delivery unit of a SEMS was introduced into the bile duct over the guidewire via the sinus tract. The SEMS was then successfully deployed through the stenosis. No stent was left in the sinus tract. This procedure yields a mature fistula through which a delivery unit can be safely introduced into the bile duct followed by uneventful deployment of a SEMS.

Solid-pseudopapillary tumor of the pancreas showing a remarkable reduction in size over the 10-year follow-up period.

An 18-year-old healthy woman was admitted to our department for further evaluation of a pancreatic mass (45 mm in diameter) by transabdominal ultrasound at a general health check. Solid-pseudopapillary tumor (SPT) was suspected from the findings of diagnostic images. Therefore, surgery was recommended. The patient and her family, however, refused surgery. Ultrasound-guided transcutaneous biopsy revealed proliferation of tumor cells with small nuclei showing a pseudopapillary arrangement. PAS positive granules and alpha-1-antitrypsin positive cells were proven, which led to the diagnosis of SPT. As the grade of atypism of the tumor cells was low, the patient underwent follow-up examination once a year at our outpatient department thereafter. The tumor gradually decreased its maximum diameter in 10 years from 45 mm to 15 mm. Thus far, there have been very few reports on the natural course of SPT, and this is the first report describing marked spontaneous shrinkage of a tumor in a long follow-up period.

Amylase levels in bile in patients with a morphologically normal pancreaticobiliary ductal arrangement.

BACKGROUND: We investigated the presence of occult pancreaticobiliary reflux in patients with a morphologically normal pancreaticobiliary ductal arrangement by measuring biliary amylase levels and compared histopathological findings of the gallbladder between groups with high and low biliary amylase levels. METHODS: In 178 patients with a normal pancreaticobiliary ductal arrangement who had undergone endoscopic retrograde cholangiopancreatography (ERCP), we sampled bile from the bile duct and measured amylase levels. Then we compared clinical features and histological findings of the gallbladder between high (HALG) and low amylase level groups (LALG). RESULTS: A high biliary amylase level was observed in 25.8% (46/178) of the patients. The prevalence of a high biliary amylase level was high in patients with gallbladder carcinoma (40%) and in those with choledocholithiasis (28.4%). The level of amylase in bile was high in patients with gallbladder carcinoma, adenomyomatosis of the gallbladder, and chronic cholecystitis. A strong correlation between the levels of amylase and lipase in bile and the dominance of amylase of pancreatic origin in bile were confirmed by isozyme analysis. Thickening of the gallbladder mucosa was a significant manifestation in HALG. Histological examination of the gallbladder mucosa showed that incidences of metaplastic change and atypical epithelium and Ki67-LI in were higher in HALG than in LALG. CONCLUSIONS: Occult pancreaticobiliary reflux is observed in a considerable number of ERCP candidates. Those who show an extremely high biliary amylase level, at least, may be at high risk for biliary malignancies.

Endoscopic biliary imaging and clinicopathological features of cystic duct cancer.

BACKGROUND: Cystic duct cancer fulfilling Farrar's criteria is relatively rare, but tumors whose origin is estimated to be in the cystic duct exist. The clinical features of such "broadly defined" cystic duct cancer have not been clarified. METHODS: The endoscopic retrograde cholangiography (ERC) findings, intraductal ultrasonography (IDUS) findings, histological findings, and prognoses of 11 cases of cystic duct cancers resected at our institution (group C) were retrospectively analyzed. As a control group, 55 cases of middle or lower bile duct cancer (group B) were used (in 20 of the 55 cases of group B, tumors extended to the cystic duct intraluminally (group B-C (+)). RESULTS: (1) ERC findings of group C as compared with those of group B-C (+) were as follows: (a) unilateral bile duct narrowing (spoon-like appearance): 55% versus 5% (P<0.01); (b) bilateral bile duct narrowing (apple-core-like appearance): 27% versus 95% (P<0.001). (2) IDUS was unable to visualize the cysticocholedochal junction (negative "confluence sign") more often in group C (67%) than in group B-C (+) (13%) (P<0.01). (3) Histologically, tumors extended to the gallbladder and the bile duct in 36% and 91% of the cases in group C, respectively. (4) The median survival time of the two groups was 21 and 28 months, respectively. CONCLUSIONS: Cystic duct cancers frequently extended to the bile duct. The spoon-like appearance by ERC and the negative confluence sign by IDUS were characteristic findings.

Ultrasonographic findings and natural history of intraductal papillary-mucinous neoplasms of the pancreas.

It is clear that the prevalence of malignancy is high in the main-duct type of intraductal papillary-mucinous neoplasm (IPMN). Branch-duct IPMNs include several histologic conditions such as carcinoma, adenoma, and hyperplasia. Intraductal papillary adenocarcinoma and papillary adenoma are characterized by papillary protrusions and thick septum-like structures in dilated ducts as delineated by ultrasonography. A solid mass showing a mixedecho pattern in the pancreatic parenchyma is a characteristic finding of invasive types of IPMN. The international guidelines for the management of branch-duct IPMNs suggest that the appearance of symptoms attributable to the cyst, the presence of intramural nodules, a cyst size greater than 30 mm, and dilation of the main pancreatic duct (>6 mm) are indications for resection. Based on the relationship between the height of a papillary protrusion and the diameter of a cystic dilated branch as well as on histological findings, branch-duct IPMNs with papillary protrusions more than 10 mm in height as shown by imaging should be resected, and it is not adequate to differentiate carcinoma from other lesions based on the diameter of cystic branches alone. A follow-up study on branch-duct IPMNs revealed that most papillary protrusions showed a slow increase in size or development of lateral spread, and that there was no development of cancer with stromal invasion during an average follow-up of 46 months. Therefore, the presence of intramural nodules alone should not be an indication for surgery. Also, patients without papillary protrusions or thick septum-like structures are not immediate candidates for surgery. Invasive adenocarcinoma can develop at a pancreatic site different from the area of interest showing cystic changes, with such invasion possibly being multicentric. Therefore, in patients with branch-duct IPMNs, attention should be paid to the entire pancreas when performing follow-up examinations.

Clinicopathological study on the intraductal spread of small pancreatic cancer.

BACKGROUND: The aim of this study was to evaluate histopathologically the frequency, direction, and length of intraductal spread (IS) along the main pancreatic duct from the main tumor of small pancreatic cancer. METHODS: Resected specimens from 20 cases of pTS1 (histologically 2 cm or less in diameter) pancreatic cancer (September 1983 to December 2005) were examined histopathologically. As controls, 40 resected specimens from cases of pTS2 (more than 2 cm and less than 4 cm in diameter) or larger sized pancreatic cancer (pTS2