Novel characteristics of traction force in biliary self-expandable metallic stents.

BACKGROUND AND AIM: In recent years, knowledge concerning the mechanical properties of self-expandable metallic stents (SEMS) has increased. In a previous study, we defined traction force and traction momentum and reported that these characteristics are important for optimal stent deployment. However, traction force and traction momentum were represented as relative values and were not evaluated in various conditions. The purpose of the present study was to measure traction force in various situations assumed during SEMS placement. METHODS: Traction force and traction momentum were measured in non-stricture, stricture, and angled stricture models using in-house equipment. RESULTS: Stricture and angled stricture models had significantly higher traction force and traction momentum than those of the non-stricture model (stricture vs non-stricture: traction force, 7.2 N vs 1.4 N, P < 0.001; traction momentum, 237.8 Ns vs 62.3 Ns, P = 0.001; angled stricture vs non-stricture: traction force, 7.4 N vs 1.4 N, P < 0.001; traction momentum, 307.2 Ns vs 62.3 Ns, P < 0.001). Traction force was variable during SEMS placement and was categorized into five different stages, which were similar in both the stricture and angled stricture models. CONCLUSIONS: We measured traction force and traction momentum under simulated clinical conditions and demonstrated that strictures and the angular positioning of the stent influenced the traction force. Clinicians should be aware of the transition of the traction force and should schedule X-ray imaging during SEMS placement.

Endoscopic retrograde cholangiopancreatography-related adverse events in patients with type 1 autoimmune pancreatitis.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is frequently performed for the diagnosis and treatment of type 1 autoimmune pancreatitis (AIP). However, the prevalence of ERCP-related adverse events in patients with type 1 AIP has not been evaluated. We aimed to clarify the feasibility of ERCP in patients with type 1 AIP. METHODS: We retrospectively reviewed 82 consecutive ERCP procedures performed in patients with type 1 AIP from 2004 to 2014 in one university hospital and three tertiary-care referral centers. One hundred four ERCP procedures in chronic pancreatitis and 1123 in non-AIP cohort were enrolled as control groups. We compared the incidence of post-ERCP pancreatitis (PEP) between type 1 AIP and control groups. We evaluated the incidence of ERCP-related adverse events and various predictive factors for hyperamylasemia after ERCP. RESULTS: Pancreatography and cholangiography by ERCP were obtained in 78 (95.1%) and 76 (92.7%) patients, respectively. The incidence of PEP, cholangitis, and bleeding was 1.2% (1/82), 0%, and 1.2%, respectively. PEP occurred in type 1 AIP patient with diffuse parenchymal imaging, and the severity was mild. The incidences of PEP were 2.9% (3/104) and 5.4% (61/1123) in chronic pancreatitis and normal cohort, respectively. The incidence of PEP was slightly lower in type 1 AIP than non-AIP cohort (1.2% vs 5.8%, p = 0.119). There were no significant predictive factors for hyperamylasemia after ERCP in type 1 AIP. CONCLUSIONS: The incidence of ERCP-related adverse events is low in patients with type 1 AIP. ERCP-related procedures are feasible in the diagnosis and treatment of AIP.

New concept of traction force applied to biliary self-expandable metallic stents.

BACKGROUND AND STUDY AIMS: Various mechanical properties of self-expandable metallic stents (SEMSs) have been reported. They can be classified into the device behavior during and after deployment. While there have been several reports on the latter, information on the former is insufficient. During deployment, the position is maintained by retracting the delivery catheter. We propose that this pulling force be called the traction force and that the magnitude of traction force is termed the traction momentum. The aim of this study was to measure these parameters in order to clarify the properties of SEMSs in terms of their deployment. MATERIAL AND METHODS: The traction force, traction momentum, and shortening rate of 10 different SEMSs were measured. Traction force was measured using in-house equipment, and the shortening rate was determined by measuring the stents. RESULTS: The shortening rate was closely related to the stent structure. The traction force varied between 1.5 N and 9.4 N, and the traction momentum was significantly elevated in covered and braided stents. A high traction force did not imply a high traction momentum. CONCLUSIONS: A low or constant traction force and a minimal shortening rate significantly facilitated SEMS deployment to optimal positions. Traction force could be an important element for new ideal SEMS design.

Clinical features of acute obstructive suppurative pancreatic ductitis: A retrospective review of 20 cases.

BACKGROUND AND AIMS: The clinical features of acute obstructive suppurative pancreatic ductitis (AOSPD) have not been elucidated. We aimed to clarify the clinical features of AOSPD. METHODS: We retrospectively reviewed the clinical features of 20 patients with AOSPD at two tertiary referral centers between 1993 and 2012. We compared 17 AOSPD patients with chronic pancreatitis (CP) and 42 patients with acute-on-CP in terms of clinical characteristics, presentation, and laboratory and imaging findings. RESULTS: The etiology of AOSPD involved CP in 17 (85%) patients, pancreatic ductal adenocarcinoma in 2 (10%), and intraductal papillary mucinous neoplasm in 1 (5%). Endoscopic pancreatic drainage was effective in 19 (95%) patients. Body temperature was significantly higher in AOSPD with CP than acute-on-CP patients (median: 38.2 vs 36.9 °C; P < 0.001). Serum amylase levels at onset were significantly lower (median: 133 vs 364.5 U/L; P = 0.009), and C-reactive protein was significantly higher (median: 9.42 vs 1.06 mg/dL; P < 0.001) in AOSPD with CP patients. Enlargement of the pancreatic parenchyma (18 vs 93%; P < 0.001) and stranding of the surrounding fat (12 vs 93%; P < 0.001) on computed tomography were observed less frequently in patients with AOSPD with CP patients. The diameter of the main pancreatic duct was significantly greater in AOSPD with CP than acute-on-CP patients (median: 7 vs 5 mm; P = 0.006). CONCLUSIONS: The major etiology of AOSPD involved CP, and endoscopic pancreatic drainage was effective. The clinical features differ between AOSPD with CP and acute-on-CP.

Correlation between long-term outcome and steroid therapy in type 1 autoimmune pancreatitis: relapse, malignancy and side effect of steroid.

OBJECTIVES: Autoimmune pancreatitis (AIP) responds well to corticosteroid therapy (CST), and CST is essential to induce remission. However, the correlation between long-term outcome and CST has not been evaluated. We aimed to clarify the correlation between long-term outcome of AIP and CST. MATERIAL AND METHODS: We retrospectively evaluated relapse, risk of malignancy and side effects of CST by focusing on the correlation with CST in 84 patients with type 1 AIP. RESULTS: The incidence of relapse was 23.8%. The frequency of relapse after CST administration was significantly lower in patients taking CST for >6 months than in those who did not (22% versus 67%; p = 0.036). The incidence of malignancy was 10.7%. The standardized incidence ratio of malignancy was 2.14 [95% confidence interval 0.74-3.54]. There were no significant correlations between development of malignancy and CST. The incidences of total and serious side effects due to CST were 75% and 19.1%, respectively. Relapse was the only significant independent predictive risk factor for serious side effects in a multivariate analysis (odds ratio 4.065; 95% confidence interval 1.125-14.706; p = 0.032). The cumulative dose of corticosteroid was significantly higher in patients with serious side effects than in those without (12,645 mg versus 7322 mg; p = 0.041). CONCLUSIONS: CST reduces relapse of AIP. However, CST causes serious side effects, particularly in relapsing patients. Alternative maintenance therapy to prevent relapse is needed.

Comparison of intraductal ultrasonography findings between primary sclerosing cholangitis and IgG4-related sclerosing cholangitis.

BACKGROUND AND AIM: Comparisons of intraductal ultrasonography (IDUS) findings between primary sclerosing cholangitis (PSC) and IgG4-related sclerosing cholangitis (IgG4-SC) have not been elucidated. We aimed to clarify the differences in transpapillary IDUS findings between PSC and IgG4-SC. METHODS: We retrospectively compared transpapillary IDUS findings between 15 patients with PSC and 35 patients with IgG4-SC between 2004 and 2014. RESULTS: IDUS findings of circular-asymmetric wall thickness, irregular inner margin, diverticulum-like outpouching, unclear outer margin, heterogeneous internal echo, and disappearance of three layers were significantly higher in PSC than in IgG4-SC (P < 0.001). Irregular inner margin, diverticulum-like outpouching, and disappearance of three layers were specific IDUS findings for PSC compared to IgG4-SC. Diverticulum-like outpouching on IDUS and endoscopic retrograde cholangiogram (ERC) was observed in 10 (67%) and five (33%) of 15 patients with PSC, respectively. However, based on IDUS and ERC, diverticulum-like outpouching was not observed in any patient with IgG4-SC. All five patients with diverticulum-like outpouching on ERC had diverticulum-like outpouching on IDUS, and five (50%) of 10 patients without diverticulum-like outpouching on ERC had diverticulum-like outpouching on IDUS. CONCLUSIONS: The IDUS findings differed between PSC and IgG4-SC. Irregular inner margin, diverticulum-like outpouching, and disappearance of three layers are specific IDUS findings for PSC compared to IgG4-SC. IDUS is a more useful procedure than ERC for the early detection of diverticulum-like outpouching.

Stent under-expansion on the procedure day, a predictive factor for poor oral intake after metallic stenting for gastric outlet obstruction.

BACKGROUND AND AIM: Self-expandable metallic stents (SEMS) have been widely accepted as palliation therapy for malignant gastric outlet obstruction (GOO). However, the factors predictive of poor oral intake after SEMS placement have not been elucidated sufficiently. We aimed to clarify both the patient and stent-related predictive factors. METHODS: We retrospectively reviewed 126 consecutive patients who underwent uncovered SEMS placement for malignant GOO between April 2010 and March 2013 at a university hospital and two tertiary care referral centers. RESULTS: Technical success of SEMS placement was achieved in all 126 (100%) patients. Improved oral intake was observed in 111 (88.1%) patients. A Karnofsky performance status ≤ 40 (odds ratio [OR], 1.19; 95% confidence interval [CI], 1.02-1.28; P = 0.041), peritoneal dissemination (OR, 1.20; 95% CI, 1.01-1.26; P = 0.038), and under-expansion of the SEMS on the procedure day (OR, 1.55; 95% CI, 1.26-1.62; P < 0.001) were independent predictive factors for poor improvement on the GOO scoring system, according to multivariate analysis. CONCLUSIONS: SEMS under-expansion was a stent related, while poor performance status and peritoneal dissemination were patient related, predictive factors for poor oral intake after SEMS placement for malignant GOO.

Safety and benefits of self-expandable metallic stents with chemotherapy for malignant gastric outlet obstruction.

BACKGROUND AND AIM: The influence of chemotherapy on placement of self-expandable metallic stents (SEMS) for malignant gastric outlet obstruction (MGOO) has not been evaluated extensively. We investigated the influence of chemotherapy on the clinical outcomes of SEMS placement for MGOO. METHODS: A total of 152 cancer patients with MGOO from a university hospital and affiliate hospitals were included. The patients were classified according to chemotherapy status and evaluated for palliative efficacy and safety of SEMS placement. RESULTS: Technical success rate, time to oral intake, and parameters indicating improvement of physical condition did not differ between the with- and without-chemotherapy groups after stent placement. Re-intervention and stent migration were significantly more frequent in the with-chemotherapy group than in the without-chemotherapy group after stent placement (re-intervention, 32.4% vs 7.8%, P = 0.0005; stent migration, 13.5% vs 1.7%, P = 0.0097). The frequency of adverse events did not differ between the with- and without-chemotherapy groups. Although chemotherapy after stent placement was an independent predictive factor for shortening the stent patency period (hazard ratio [HR], 3.10; P = 0.0264), the use of additional stents facilitated uneventful recovery and further prolonged survival time (HR, 0.60; P = 0.0132). CONCLUSIONS: Various cancer patients with MGOO can undergo SEMS placement safely regardless of chemotherapy, and concurrent chemotherapy after stent placement can prolong survival time, although re-intervention and stent migration may be increased.

A comparison of the diagnostic efficacy in type 1 autoimmune pancreatitis based on biopsy specimens from various organs.

BACKGROUND: Comprehensive immunostaining evaluation of the biopsy specimens from various organs with type 1 autoimmune pancreatitis (AIP) has not been elucidated. Our aim was to clarify which of these biopsy specimens and counting method could be a useful tool for supporting the diagnosis of AIP. METHODS: We retrospectively evaluated biopsy specimens from pancreas (n = 19), stomach (n = 28), duodenum (n = 27), duodenal papilla (n = 25), colon (n = 19), liver (n = 11), bile duct (n = 24), and minor salivary gland (n = 13) in 36 patients with AIP. Positive IgG4 immunostaining (>10 plasma cells/high-power field [HPF]) and positive IgG4/IgG ratio (>40%) of biopsy specimens from 8 sites of 6 organs in one HPF and an average from 3 HPFs were compared between AIP and controls. RESULTS: The sensitivity of IgG4 immunostaining for AIP in one HPF were 16% in pancreas, 14% in stomach, 15% in duodenum, 52% in duodenal papilla, 11% in colon, 27% in liver, 21% in bile duct and 8% in minor salivary gland, respectively. The positive IgG4 immunostaining of the duodenal papilla in one HPF showed the highest sensitivity (52%) and accuracy (73%) among the 8 sites. It also showed the highest sensitivity among 4 different counting methods (IgG4 immunostaining in one HPF and 3 HPFs, both IgG4 immunostaining and IgG/IgG4 ratio in one HPF and 3 HPFs), but there were no significant differences with respect to specificity and accuracy. CONCLUSIONS: IgG4 immunostaining of swollen duodenal papilla with more than 10 IgG4-positive plasma cells in at least one HPF is useful for supporting the diagnosis of AIP.

Feasibility of endoscopic retrograde cholangiopancreatography-related procedures in hemodialysis patients.

BACKGROUND AND AIM: The opportunities of endoscopic retrograde cholangiopancreatography (ERCP)-related procedure for hemodialysis (HD) patients have been increasing recently. However, the complication rate of ERCPs in HD patients has not been evaluated sufficiently. We aimed to clarify the feasibility of ERCPs in HD patients. METHODS: We retrospectively reviewed 76 consecutive ERCPs for HD patients between January 2005 and December 2012 in one university hospital and three tertiary-care referral centers. Endoscopic sphincterotomy (EST) was performed in 21 HD patients. We evaluated the incidence and risk factors for complications of all ERCPs and EST in HD patients. RESULTS: The incidence of pancreatitis, cholangitis, and cardiopulmonary complications for ERCPs in HD patients was 7.9% (6/76), 1.3% (1/76), and 1.3% (1/76), respectively. The mortality rate was 2.6% (2/76), and it occurred after acute pancreatitis in one patient and pneumonia in the other patient. The incidence of hemorrhage and pancreatitis with EST was 19% (4/21) and 4.8% (1/21), respectively. The duration of HD was significantly longer in the patients with hemorrhage after EST than without (19.5 vs 6 years; P = 0.029). CONCLUSIONS: ERCP is feasible in HD patients. However, EST is not advisable because of the high hemorrhage rate, particularly for patients with a long duration of HD.

Autoimmune pancreatitis presenting a short narrowing of main pancreatic duct with subsequent progression to diffuse pancreatic enlargement over 24 months; natural history of autoimmune pancreatitis.

CONTEXT: Initial pancreatogram and natural history of autoimmune pancreatitis (AIP) have not been clarified, and there were few recent studies concerning the association between AIP and intraductal papillary mucinous neoplasm (IPMN). CASE REPORT: We report an 81-year- old man with AIP associated with IPMN. Although the initial pancreatogram was normal, a short narrowing of the main pancreatic duct (MPD) appeared during a follow-up for IPMN after 6 months, which was highly suggestive of pancreatic cancer. A narrowing of the MPD extended after 15 months, and this progressed to diffuse narrowing of the MPD with an elevation in the serum IgG4 levels after 24 months. Finally, the patient was diagnosed with diffuse-type AIP, according to the Japanese diagnostic criteria 2011 and the International Consensus Diagnostic Criteria. Considering the natural history of AIP, this marked change of the MPD is indicative of this condition. CONCLUSION: We report a case of AIP presenting with a short narrowing of the MPD with subsequent progression to diffuse pancreatic enlargement during a follow-up for IPMN.

Predictive factors for pancreatitis and cholecystitis in endoscopic covered metal stenting for distal malignant biliary obstruction.

BACKGROUND AND AIM: Pancreatitis and cholecystitis are major complications after self-expandable metal stent (SEMS) placement in distal malignant biliary obstruction. We aimed to clarify predictive factors for pancreatitis and cholecystitis after covered SEMS placement. METHODS: We retrospectively reviewed 74 consecutive patients with distal malignant biliary obstruction who underwent initial endoscopic drainage using covered SEMS. Predictive factors for pancreatitis and cholecystitis were evaluated in the 74 patients described above and in 66 patients who had not undergone cholecystectomy. RESULTS: The incidences of pancreatitis and cholecystitis were 10.8% (8/74) and 6.1% (4/66), respectively. Univariate analysis revealed that non-pancreatic cancer (P = 0.018) and contrast injection into the pancreatic duct (P = 0.030) were significant predictive factors for pancreatitis. Multivariate analysis revealed that non-pancreatic cancer (odds ratio [OR], 4.21; 95% confidence interval [CI], 1.63-14.18; P = 0.007) and contrast injection into the pancreatic duct (OR, 3.34; 95% CI, 1.33-9.60; P = 0.016) were significant independent predictive factors for pancreatitis. On the other hand, univariate and multivariate analyses revealed that tumor involvement to the orifice of the cystic duct (OCD) was a significant independent predictive factor for cholecystitis (OR, 5.85; 95% CI, 1.91-27.74; P = 0.005). CONCLUSIONS: Non-pancreatic cancer and contrast injection into the pancreatic duct were predictive factors for pancreatitis, and tumor involvement to the OCD was a positive predictive factor for cholecystitis after endoscopic covered SEMS placement for distal malignant biliary obstruction.

Neuroendocrine carcinoma of the ampulla of Vater causing ectopic adrenocorticotropic hormone-dependent Cushing's syndrome.

Ectopic adrenocorticotropic hormone (ACTH) is rarely secreted by neuroendocrine tumors. Although neuroendocrine tumors may occur at any site in the gastrointestinal system, they very rarely occur in the ampulla of Vater and have a poor prognosis. The present study described the first Cushing's syndrome as a result of ectopic ACTH arising from the ampulla of Vater neuroendocrine carcinoma. A 69-year-old female was admitted with clinical features of Cushing's syndrome, confirmed biochemically by hypokalemia, and elevated levels of ACTH and cortisol. In further investigations, a tumor of the ampulla of Vater and liver metastases were detected. Pathological analysis of the biopsy confirmed a neuroendocrine carcinoma, which was immunohistochemically positive for chromogranin A, synaptophysin, cluster of differentiation 56 and ACTH. Therefore, the present study diagnosed a functional and metastatic neuroendocrine carcinoma of the ampulla of Vater with ectopic ACTH production causing Cushing's syndrome. The patient succumbed to mortality 4 months later, despite administration of combined chemotherapy with irinotecan and cisplatin.

IgG4-related Sclerosing Cholangitis with No Biliary Stricture but Severe Thickening of the Bile Duct Wall.

We herein report a case of a 56-year-old man with IgG4-related sclerosing cholangitis (IgG4-SC) with no biliary stricture, but with a severely thickened bile duct wall. Contrast-enhanced computed tomography showed diffuse swelling of the pancreas and thickening of the common bile duct (CBD) wall with delayed enhancement. Obvious diffuse wall thickening of the CBD was observed on endoscopic ultrasonography. However, endoscopic retrograde cholangiography showed no biliary stricture in the CBD that had thickened. Although IgG4-SC has been classified by a stenotic lesion on cholangiography, we should be aware of some IgG4-SC cases showing only bile duct wall thickness without any biliary stricture.

Predictive factors for positive diagnosis of malignant biliary strictures by transpapillary brush cytology and forceps biopsy.

OBJECTIVE: The diagnostic yields of endoscopic transpapillary brush cytology and forceps biopsies for malignant biliary strictures (MBS) remain unclear and predictive factors for diagnosis have not been established. We aimed to clarify the diagnostic yields of both methods and the predictive factors METHODS: We reviewed 241 patients with biliary strictures who underwent transpapillary brush cytology (n = 202) or forceps biopsy (n= 208) between 2004 and 2014 at a single academic center. RESULTS: The sensitivity of forceps biopsy for MBS was significantly higher than that of brush cytology [60.6% (97/160) vs 36.1% (57/158), P < 0.01). The sensitivity of forceps biopsy was significantly higher in diagnosing bile duct cancer than pancreatic cancer [78.8% (52/66) vs 42.4% (28/66), P < 0.01). Multivariate analysis revealed that serum total bilirubin (TB) level (T-Bil) ≥ 4 mg/dL [odds ratio (OR) 2.506, 95% confidence interval (CI): 1.139-5.495, P = 0.022) was an independent predictor for positive diagnosis by brush cytology, while bile duct cancer (OR 4.926, 95% CI 2.183-11.111, P < 0.001), stricture length ≥ 30 mm (OR 2.941, 95% CI 1.119-7.752, P = 0.029) and TB ≥ 4 mg/dL (OR 2.252, 95% CI 1.052-4.831, P = 0.037) were significant indicators of a positive diagnosis by forceps biopsy. CONCLUSIONS: Endoscopic transpapillary forceps biopsy shows higher sensitivity than that of brush cytology for MBS. Bile duct cancer, stricture length ≥ 30 mm and TB ≥ 4 mg/dL are good indicators of forceps biopsy.

Case of arterial hemorrhage after endoscopic papillary large balloon dilation for choledocholithiases using a covered self-expandable metallic stent.

A 78-year-old male was admitted to our hospital because of choledocholithiasis. ERC demonstrated choledocholithiases with a maximum diameter of 13 mm, and we performed endoscopic papillary large balloon dilation (EPLBD) with a size of 15 mm. Immediately following the balloon deflation, spurting hemorrhage occurred from the orifice of the duodenal papilla. Although we performed endoscopic hemostasis by compressing the bleeding point with the large balloon catheter, we could not achieve hemostasis. Therefore, we placed a 10 mm fully covered self-expandable metallic stent (SEMS) across the duodenal papilla, and the hemorrhage stopped immediately. After 1 wk of SEMS placement, duodenal endoscopy revealed ulcerative lesions in both the orifice of the duodenal papilla and the lower bile duct. A direct peroral cholangioscopy using an ultra-slim upper endoscope revealed a visible vessel with a longitudinal mucosal tear in the ulceration of the lower bile duct. We believe that the mucosal tear and subsequent ruptured vessel were caused by the EPLBD procedure.

Photodynamic Therapy using Talaporfin Sodium for the Recurrence of Cholangiocarcinoma after Surgical Resection.

We herein report the case of a 72-year-old man who underwent photodynamic therapy (PDT) with talaporfin sodium for recurrent cholangiocarcinoma after surgical resection. Endoscopic retrograde cholangiography (ERC) showed severe stenosis with an irregular surface measuring approximately 1 cm in length from the anastomotic site, and a recurrent nodular lesion was observed at the anastomotic site of the right anterior intrahepatic bile duct on gastrointestinal endoscopy. ERC after PDT revealed a dramatic improvement in the bile duct stenosis, and the nodular lesion had disappeared. No adverse events from the PDT were detected. PDT using talaporfin sodium may be a safe alternative treatment for cholangiocarcinoma.

Comparison study of immunohistochemical staining for the diagnosis of type 1 autoimmune pancreatitis.

BACKGROUND: Various methods to evaluate immunohistochemical staining (IHC) for the diagnosis of type 1 autoimmune pancreatitis (AIP) have been proposed. Our goal was to determine the most useful IHC method for the diagnosis of AIP. METHODS: Specimens of AIP (18 patients), chronic pancreatitis (CP, 24 patients), and pancreatic ductal adenocarcinoma (PDA, 45 patients) were evaluated with IHC for immunoglobulin G (IgG), IgG1, IgG4, and CD138 (syndecan-1). The number of IHC-positive cells was counted in 3, 5, and 10 different high-power fields (HPFs) by selecting fields with the most numerous positive cells (hotspot) or by randomly selecting fields in the affected areas (random). We evaluated the mean number of IgG4-positive plasma cells (IgG4+)/HPF (mean IgG4+), the number of fields with >10 and >50 IgG4+ (NOF >10 and NOF >50 IgG4+), the ratio of IgG4+/IgG+, IgG4+/IgG1+, and IgG4+/CD138+. RESULTS: Analysis with receiver operator characteristic curves revealed that accurate and practical parameters in 3 HPFs were mean IgG4+ with the hotspot method (sensitivity, 88.9; specificity, 92.8 %), mean IgG4+ with the random method (100, 95.7 %), and NOF >10 IgG4+ with the random method (94.4, 97.1 %). These results were as accurate as results from 5 HPFs to 10 HPFs. The combination of mean IgG4+ and IgG4+/IgG+ did not provide more accurate diagnosis for AIP than a single criterion itself. CONCLUSIONS: Mean IgG4+ or NOF >10 IgG4+ with the random method in 3 HPFs was a useful and simple diagnostic method for AIP. The combined criteria of mean IgG4+ and IgG4+/IgG+ might not be required for accurate diagnosis of AIP.

Locus/chromosome aberrations in intraductal papillary mucinous neoplasms analyzed by fluorescence in situ hybridization.

Locus and chromosome abnormalities have not been well clarified in intraductal papillary mucinous neoplasms (IPMNs). The aim of this study was to retrospectively examine these abnormalities using fluorescence in situ hybridization. IPMNs (n=28) were histopathologically classified into noninvasive IPMN (n=17) and IPMN with an associated invasive carcinoma (invasive IPMN, n=11) groups. Noninvasive IPMNs possessed non-neoplastic and noninvasive spots in their tissues, and invasive IPMN cases possessed non-neoplastic, noninvasive, and invasive spots. Non-neoplastic (n=28), noninvasive (n=28), and invasive (n=11) spots were then analyzed for aneuploidy of chromosomes 3, 6, 7, 8, 17, and 18 and deletions of p16 and p53 loci. Polysomy 6 and p16 deletion were significantly more frequent in noninvasive than in non-neoplastic spots. Polysomy 7, polysomy 18, p16 deletion, and p53 deletion were significantly more frequent in invasive than in noninvasive spots. Detection of polysomy 7 and p53 deletion gave a high diagnostic accuracy for invasive IPMN (sensitivity, 90.9%; specificity, 94.1%; and accuracy, 92.5%). Our study suggests that: (1) polysomy 6 and p16 deletion may contribute to adenomatous change of IPMN; (2) polysomy 7, polysomy 18, p16 deletion, and p53 deletion play roles in malignant transformation of noninvasive IPMN; and (3) polysomy 7 and p53 deletion may be excellent diagnostic markers for invasive IPMN.