Sensitivity of endoscopic ultrasound-guided fine-needle aspiration cytology and biopsy for a diagnosis of pancreatic ductal adenocarcinoma: A comparative analysis.

The utility of endoscopic ultrasound fine-needle aspiration cytology (EUS-FNAC) or endoscopic ultrasound fine-needle aspiration biopsy (EUS-FNAB) for diagnosis of small and large pancreatic ductal adenocarcinomas (PDACs) remains in question. We addressed this by analyzing 97 definitively diagnosed cases of PDAC, for which both EUS-FNAC and EUS-FNAB had been performed. We subclassified the 97 solid masses into small (n = 35) or large (n = 62) according to the maximum tumor diameter (<24 mm or ≥24 mm) and compared the diagnostic sensitivity (truly positive rate) of EUS-FNAC and of EUS-FNAB for small and large masses. Diagnostic sensitivity of EUS-FNAC did not differ between large and small masses (79.0% vs. 60.0%; p = 0.0763). However, the diagnostic sensitivity of EUS-FNAB was significantly higher for large masses (85.5% vs. 62.9%; p = 0.0213). Accurate EUS-FNAC-based diagnosis appeared to depend on the degree of cytological atypia of cancer cells, which was not associated with quantity of cancer cells. The accuracy of EUS-FNAB-based diagnosis appeared to depend on cancer cell viability in large masses and cancer volume in small masses. Based on the advantages or disadvantages in each modality, both modalities play an important role in the qualitative diagnosis of PDAC as a complementary procedure.

Pancreatobiliary Maljunction-associated Gallbladder Cancer Is as Common in the West, Shows Distinct Clinicopathologic Characteristics and Offers an Invaluable Model for Anatomy-induced Reflux-associated Physio-chemical Carcinogenesis.

OBJECTIVE: To determine the associations of pancreatobiliary maljunction (PBM) in the West. BACKGROUND: PBM (anomalous union of common bile duct and pancreatic duct) is mostly regarded as an Asian-only disorder, with 200X risk of gallbladder cancer (GBc), attributed to reflux of pancreatic enzymes. Methods: Radiologic images of 840 patients in the US who underwent pancreatobiliary resections were reviewed for PBM and contrasted with 171 GBC cases from Japan. RESULTS: Eight % of the US GBCs (24/300) had PBM (similar to Japan; 15/ 171, 8.8%), in addition to 1/42 bile duct carcinomas and 5/33 choledochal cysts. None of the 30 PBM cases from the US had been diagnosed as PBM in the original work-up. PBM was not found in other pancreatobiliary disorders. Clinicopathologic features of the 39 PBM-associated GBCs (US:24, Japan:15) were similar; however, comparison with non-PBM GBCs revealed that they occurred predominantly in females (F/M = 3); at younger (<50-year-old) age (21% vs 6.5% in non-PBM GBCs; P = 0.01); were uncommonly associated with gallstones (14% vs 58%; P < 0.001); had higher rate of tumor-infiltrating lymphocytes (69% vs 44%; P = 0.04); arose more often through adenoma-carcinoma sequence (31% vs 12%; P = 0.02); and had a higher proportion of nonconventional carcinomas (21% vs 7%; P = 0.03). Conclusions: PBM accounts for 8% of GBCs also in the West but is typically undiagnosed. PBM-GBCs tend to manifest in younger age and often through adenoma-carcinoma sequence, leading to unusual carcinoma types. If PBM is encountered, cholecystectomy and surveillance of bile ducts is warranted. PBM-associated GBCs offer an invaluable model for variant anatomy-induced chemical (reflux-related) carcinogenesis.

Pancreatic ductal adenocarcinomas associated with intraductal papillary mucinous neoplasms (IPMNs) versus pseudo-IPMNs: relative frequency, clinicopathologic characteristics and differential diagnosis.

The literature is highly conflicted on what percentage of pancreatic ductal adenocarcinomas (PDACs) arise in association with intraductal papillary mucinous neoplasms (IPMNs). Some studies have claimed that even small (Sendai-negative) IPMNs frequently lead to PDAC. Recently, more refined pathologic definitions for mucin-lined cysts were provided in consensus manuscripts, but so far there is no systematic analysis regarding the frequency and clinicopathologic characteristics of IPMN-mimickers, i.e., pseudo-IPMNs. In this study, as the first step in establishing frequency, we performed a systematic review of the pathologic findings in 501 consecutive ordinary PDACs, which disclosed that 10% of PDACs had associated cysts ≥1 cm. While 31 (6.2%) of these were IPMN or mucinous cystic neoplasm (MCN), 19 (3.8%) were other cyst types that mimicked IPMN (pseudo-IPMNs) per recent WHO/consensus criteria. As the second step of the study, we performed a comparative clinicopathologic analysis by also including our entire surgical pathology/consultation databases that was comprised of 60 IPMN-associated PDACs, 30 MCN-associated PDACs and 40 pseudo-IPMN-associated PDACs. We found that 84% of true IPMNs were pre-operatively recognized, whereas IPMN was considered in differential diagnosis of 33% of pseudo-IPMNs. Of the 40 pseudo-IPMNs, there were 15 secondary duct ectasias; 6 large-duct-type PDACs; 5 pseudocysts; 5 cystic tumor necrosis; 4 simple mucinous cysts; 3 groove pancreatitis-associated paraduodenal wall cysts; and 2 congenital cysts. Microscopically, pseudo-IPMNs had at least partial mucinous-lining mimicking IPMN but had smaller cystic (mean = 1.9 cm) and larger PDAC (mean = 3.8 cm) components compared to true IPMNs (cyst = 5.7 cm; PDAC = 2.0 cm). In summary, in this pathologically verified analysis that utilized refined criteria, 10% of PDACs were discovered to have cysts ≥1 cm, about two-thirds of which were IPMN/MCN but about one-third were pseudo-IPMNs. True IPMNs underlying the PDACs are often large and are already diagnosed pre-operatively as having an IPMN component, whereas only a third of the pseudo-IPMNs receive IPMN diagnosis by imaging and their cysts are smaller. At the histopathologic level, pseudo-IPMNs are highly prone to misdiagnosis as IPMN, which presumably accounts for much higher association of IPMNs with PDAC as reported in some studies. The subtle but salient characteristics of pseudo-IPMNs elucidated in this study should be combined with careful radiological/clinical correlation in order to exclude pseudo-IPMNs.

Frequency and clinicopathologic associations of DNA mismatch repair protein deficiency in ampullary carcinoma: Routine testing is indicated.

BACKGROUND: The significance of DNA mismatch repair (MMR) deficiency in ampullary cancers (ACs) has not been established. METHODS: In total, 127 ACs with invasive carcinomas measuring ≥3 mmthat had adequate tissue were analyzed immunohistochemically. RESULTS: MMR loss was detected in 18% of ACs (higher than in colorectal cancers). Twelve tumors with MLH1-PMS2 loss were negative for BRAF V600E mutation, suggesting a Lynch syndrome association. MMR-deficient tumors (n = 23), comparedwith MMR-intact tumors (n = 104), showed a striking male predominance (male:female ratio, 4.7). Although the deficient tumors had slightly larger invasion size (2.7 vs 2.1 cm), they also had more expansile growth and less invasiveness, including less perineural invasion, and they ultimately had lower tumor (T) classification and less lymph node metastasis (30% vs 53%; P = .04). More important, patients who had MMR-deficient tumors had better clinical outcomes, with a 5-year overall survival rate of 68% versus 45% (P = .03), which was even more pronounced in those who had higher Tclassification (5-year overall survival, 69% vs 34%; P = .04). MMR deficiencyhad a statistically significant association with medullary phenotype, pushing-border invasion, and tumor-infiltrating immune cells, and it occurred more frequently in ampullary-duodenal type tumors. Programed cell death-ligand 1 (PD-L1) levels analyzed in the 22 MMR-deficient ACs revealed that all medullary carcinomas were positive. Nonmedullary MMR-deficient carcinomas expressed PD-L1 in 33% of tumors cells according to the criteria for a combined positive score ≥1, but all were negative according to the tumor proportion score≥1 method. CONCLUSIONS: In ACs, MMR deficiency is even more frequent (18%) than in colon cancer and often has a Lynch-suggestive profile, thus routine testing is warranted. Male gender, pushing-border infiltration, ampullary-duodenal origin, medullary histology, and tumor-related inflammation have a significantly higher association with MMR deficiency. MMR-deficient tumors have less aggressive behavior. PD-L1 expression is common in medullary-phenotype ACs, thus immunotherapy should be considered at least for this group.

Variant anatomy of the biliary system as a cause of pancreatic and peri-ampullary cancers.

BACKGROUND: The cause of most pancreatic and periampullary cancers (PAC) is unknown. Recently, anatomic variations such as pancreatobiliary maljunction have been recognized as risk factors, similar to Barrett-related gastro-esophageal cancers. METHODS: Pre-operative MRI from 860 pancreatic/biliary resections, including 322 PACs, were evaluated for low-union (cystic duct joining the common hepatic duct inside of the pancreas or within 5 mm of the pancreatic border) RESULTS: Low-union, seen <10% of the population, was present in 44% of PACs (73% distal bile duct/cholangiocarcinoma, 42% pancreatic head, and 34% ampullary). It was significantly lower(11%) in conditions without connection to the ductal system (thus not exposed to the ductal/biliary tract contents), namely mucinous cystic neoplasms and intrahepatic cholangiocarcinomas(p < 0.0001). Intra-pancreatic type low-union was seen in 16% of PACs versus 2% of controls(p < 0.0001). DISCUSSION: This study establishes an association between low-union and PACs, and points to an anatomy-induced chemical/bilious carcinogenesis. This may explain why most pancreas cancers are in the head. It is possible that the same chemical milieu, caused by conditions other than low-union/insertion, may also play a role in the remaining half of PACs. This opens various treatment opportunities including milieu modifications (chemoprevention), focused screening of at-risk patients, and early detection with possible corrective actions.

Effectiveness of steroid therapy for pancreatic cysts complicating autoimmune pancreatitis and management strategy for cyst-related complications.

Objectives: Autoimmune pancreatitis (AIP) sometimes becomes complicated with pancreatic cysts, although their detailed characteristics and management strategy have not been fully determined. We aimed to clarify the efficiency of steroid therapy and the risk factors for cyst formation and cyst-related complications. Methods: One hundred sixty-three AIP patients were retrospectively analyzed for relevant factors of cyst formation. We compared subjects with and without steroids to evaluate drug effectiveness on cyst size change and investigated the factors associated with cyst-related complications. Results: Thirty-two patients (19.6%) had complicating pancreatic cyst formation, and 40 cystic lesions of ≥10 mm in size were detected. Multivariate analysis revealed a drinking habit, abdominal/back pain, and elevated serum amylase to be significantly associated with cyst formation. Steroid-treated cysts became significantly reduced in size in the short-term and disappeared significantly more frequently within 1-year as compared with non-treated ones, which was confirmed by multivariate analysis. Six of 40 cysts exhibited cyst-related complications significantly associated with multilocular morphology and larger size. Conclusions: Steroid therapy is an effective choice for cysts developing in AIP to promote the release of pancreatic juice stasis. Larger lesions with multilocular morphology should be monitored closely for cyst-related complications and be considered strong candidates for steroid therapy.

Non-ampullary-duodenal carcinomas: clinicopathologic analysis of 47 cases and comparison with ampullary and pancreatic adenocarcinomas.

Literature on non-ampullary-duodenal carcinomas is limited. We analyzed 47 resected non-ampullary-duodenal carcinomas. Histologically, 78% were tubular-type adenocarcinomas mostly gastro-pancreatobiliary type and only 19% pure intestinal. Immunohistochemistry (n=38) revealed commonness of 'gastro-pancreatobiliary markers' (CK7 55, MUC1 50, MUC5AC 50, and MUC6 34%), whereas 'intestinal markers' were relatively less common (MUC2 36, CK20 42, and CDX2 44%). Squamous and mucinous differentiation were rare (in five each); previously, unrecognized adenocarcinoma patterns were noted (three microcystic/vacuolated, two cribriform, one of comedo-like, oncocytic papillary, and goblet-cell-carcinoid-like). An adenoma component common in ampullary-duodenal cancers was noted in only about a third. Most had plaque-like or ulcerating growth. Mismatch repair protein alterations were detected in 13% (all with plaque-like growth and pushing-border infiltration). When compared with ampullary (n=355) and pancreatic ductal (n=227) carcinomas, non-ampullary-duodenal carcinomas had intermediary pathologic features with mean invasive size of 2.9 cm (vs 1.9, and 3.3) and 59% nodal metastasis (vs 45, and 77%). Its survival (3-, 5-year rates of 57 and 57%) was similar to that of ampullary-duodenal carcinomas (59 and 52%; P=0.78), but was significantly better than the ampullary ductal (41 and 29%, P<0.001) and pancreatic (28 and 18%, P<0.001) carcinomas. In conclusion, non-ampullary-duodenal carcinomas are more histologically heterogeneous than previously appreciated. Their morphologic versatility (commonly showing gastro-pancreatobiliary lineage and hitherto unrecognized patterns), frequent plaque-like growth minus an adenoma component, and frequent expression of gastro-pancreatobiliary markers suggest that many non-ampullary-duodenal carcinomas may arise from Brunner glands or gastric metaplasia or heterotopic pancreatobiliary epithelium. The clinical behavior of non-ampullary-duodenal carcinoma is closer to that of ampullary-duodenal subset of ampullary carcinomas, but is significantly better than that of ampullary ductal and pancreatic cancers. The frequency of mismatch repair protein alterations suggest that routine testing should be considered, especially in the non-ampullary-duodenal carcinomas with plaque-like growth and pushing-border infiltration.

Usefulness of three-dimensional magnetic resonance cholangiopancreatography with partial maximum intensity projection for diagnosing autoimmune pancreatitis.

PURPOSE: To compare three-dimensional magnetic resonance cholangiopancreatography (MRCP) with/without partial maximum intensity projection (MIP) and endoscopic retrograde cholangiopancreatography (ERCP) in patients with autoimmune pancreatitis (AIP). MATERIALS AND METHODS: Three-dimensional MRCP and ERCP images were retrospectively analyzed in 24 patients with AIP. We evaluated the narrowing length of the main pancreatic duct (NR-MPD), multiple skipped MPD narrowing (SK-MPD), and side branches arising from the narrowed portion of the MPD (SB-MPD) using four MRCP datasets: 5 original images (MIP5), 10 original images (MIP10), all original images (full-MIP), and a combination of these three datasets (a-MIP). The images were scored using a 3- or 5-point scale. The scores of the four MRCP datasets were statistically analyzed, and the positive rate of each finding was compared between MRCP and ERCP. RESULTS: The median scores for SB-MPD on MIP5 and a-MIP were significantly higher than those on MIP10 and full-MIP. In other words, partial MIP is superior to full-MIP for visualization of detailed structures. The positive rate for SB-MPD on full-MIP was significantly lower than that on ERCP, whereas the positive rate on MIP5, MIP10, and a-MIP was not significantly different from that on ERCP. Moreover, the positive rate for NR-MPD and SK-MPD on the MRCP images was significantly higher than that on the ERCP images. CONCLUSION: Partial MIP is useful for evaluating the MPD and is comparable with ERCP for diagnosing AIP.

Pancreatic Ductal Adenocarcinoma is Spread to the Peripancreatic Soft Tissue in the Majority of Resected Cases, Rendering the AJCC T-Stage Protocol (7th Edition) Inapplicable and Insignificant: A Size-Based Staging System (pT1: ≤2, pT2: >2-≤4, pT3: >4 cm) is More Valid and Clinically Relevant.

BACKGROUND: Most studies have failed to identify any prognostic value of the current T-stage protocol for pancreatic ductal adenocarcinoma (PDAC) by the American Joint Committee on Cancer and the Union for International Cancer Control unless some grouping was performed. METHODS: To document the parameters included in this T-stage protocol, 223 consecutive pancreatoduodenectomy specimens with PDAC were processed by a uniform grossing protocol. RESULTS: Peripancreatic soft tissue (PST) involvement, the main pT3 parameter, was found to be inapplicable and irreproducible due to lack of a true capsule in the pancreas and variability in the amount and distribution of adipose tissue. Furthermore, 91 % of the cases showed carcinoma in the adipose tissue, presumably representing the PST, and thus were classified as pT3. An additional 4.5 % were qualified as pT3 due to extension into adjacent sites. The T-stage defined as such was not found to have any correlation with survival (p = 0.4). A revised T-stage protocol was devised that defined pT1 as 2 cm or smaller, pT2 as >2-4 cm, and pT3 as larger than 4 cm. This revised protocol was tested in 757 consecutive PDACs. The median and 3-year survival rates of this size-based protocol were 26, 18, 13 months, and 40 %, 26 %, 20 %, respectively (p < 0.0001). The association between higher T-stage and shorter survival persisted in N0 cases and in multivariate modeling. Analysis of the Surveillance, Epidemiology, and End Results database also confirmed the survival differences (p < 0.0001). CONCLUSIONS: This study showed that resected PDACs are already spread to various surfaces of the pancreas, leaving only about 4 % of PDACs to truly qualify as pT1/T2, and that the current T-stage protocol does not have any prognostic correlation. In contrast, as shown previously in many studies, size is an important prognosticator, and a size-based T-stage protocol is more applicable and has prognostic value in PDAC.

Extracorporeal shock wave lithotripsy treatment of pancreatic stones complicated with advanced stage autoimmune pancreatitis.

BACKGROUND: Although most patients with autoimmune pancreatitis (AIP) respond favorably to prednisolone therapy, some individuals who later suffer from pancreatic calculi may require additional extracorporeal shock wave lithotripsy (ESWL) treatment. This study compares the efficacy of ESWL for calculi in AIP with that in ordinary chronic pancreatitis (CP) and proposes a new treatment approach for pancreatic duct stones occurring in AIP. METHODS: We examined the clinical records of 8 patients with chronic stage AIP and 92 patients with ordinary CP who received ESWL for pancreatic calculi. RESULTS: The AIP group was significantly older than the CP group (69.0 vs. 56.5 years, P = 0.018). With regard to the indications for ESWL, chronic pain was significantly less frequent in the chronic stage AIP group (0% vs. 45.7%, P = 0.001), whereas preservation of pancreatic function was significantly more frequent (75% vs. 19.6%, P = 0.001). Compared with the CP group, the AIP group tended to exhibit pancreatic duct stenosis proximal to pancreatic calculi and had a lower rate of complete extraction of stones from the main pancreatic duct. Histopathological analysis of a patient with chronic stage AIP revealed widely distributed nodular pancreatitis, which was characteristic of ordinary CP, along with isolated areas of lymphoplasmacytic sclerosing pancreatitis. CONCLUSIONS: Different approaches are needed for the treatment of pancreatic calculi in chronic stage AIP and ordinary CP. Specifically, it appears that intensive ESWL therapy can be avoided or delayed in AIP if the patient displays: (1) advanced age, (2) little or no chronic pain or pancreatitis, and (3) pancreatic duct stenosis proximal to pancreatic stones. In such cases, the benefit of ESWL treatment may be outweighed by the risks involved in this procedure.

Reduced expression of αGlcNAc in Barrett's oesophagus adjacent to Barrett's adenocarcinoma--a possible biomarker to predict the malignant potential of Barrett's oesophagus.

AIMS: Gastric gland mucin contains O-glycans exhibiting terminal α1,4-linked N-acetylglucosamine residues (αGlcNAc). Recently we demonstrated that mice deficient in αGlcNAc in gastric gland mucin develop gastric adenocarcinoma spontaneously, indicating that αGlcNAc is a tumour suppressor for gastric cancer. However, the role of αGlcNAc in Barrett's oesophagus (BO) remains unknown. In this study, we investigated whether reduced αGlcNAc expression in BO is associated with development of Barrett's adenocarcinoma (BAC). METHODS AND RESULTS: Thirty-five BO lesions adjacent to BAC were examined by immunohistochemistry for αGlcNAc, MUC6 and CDX2. As controls, 35 BO lesions without BAC obtained from patients with oesophageal squamous cell carcinoma were also analysed. Expression of αGlcNAc relative to its scaffold MUC6 in BO adjacent to BAC was reduced significantly compared to control BO. Decreased αGlcNAc expression in BO adjacent to BAC was particularly significant in patients with smaller tumour size (<20 mm) and minimal invasion of tumour cells to the superficial muscularis mucosae. There was also a significant inverse correlation between αGlcNAc and CDX2 expression in BO adjacent to BAC. CONCLUSIONS: Decreased expression of αGlcNAc compared with MUC6 in BO is a possible hallmark in predicting BAC development.

Mucosal damage in pancreaticobiliary maljunction is stronger in the gallbladder than in the bile duct.

BACKGROUND: The frequency of gallbladder carcinoma is high in pancreaticobiliary maljunction (PBM), and the mechanism of carcinogenesis is not well understood. METHODS: The expression of γH2AX, the most sensitive marker for detecting DNA damage, was analyzed using immunohistochemistry in patients with PBM, in which the gallbladder and bile duct were simultaneously resected. Gallbladder and bile ducts were evaluated in non-neoplastic regions in 13 cases of PBM without cancer in the gallbladder and bile ducts. RESULTS: The median frequencies of γH2AX expression in the bile duct and gallbladder within the same case were 5.9% (range 1.7-12.05%) and 9.9% (range 2.8-25%), respectively, and were significantly higher in the gallbladder mucosa (P < 0.0004). γH2AX expression strongly correlated in the bile duct and gallbladder (r = 0.9436, P < 0.0001). PBM caused marked mucosal damage to the gallbladder. CONCLUSIONS: Mucosal damage may be involved in carcinogenesis, which may be useful for predicting malignant transformation.

Establishment of a serum IgG4 cut-off value for the differential diagnosis of IgG4-related sclerosing cholangitis: a Japanese cohort.

BACKGROUND AND AIM: IgG4-related sclerosing cholangitis (IgG4-SC) must be precisely distinguished from primary sclerosing cholangitis and cholangiocarcinoma (CC) because the treatments are completely different. However, the pathological diagnosis of IgG4-SC is difficult. Therefore, highly specific non-invasive criteria such as serum IgG4 should be established. This study established a cut-off for serum IgG4 to differentiate IgG4-SC from respective controls using serum IgG4 levels measured in Japanese centers. METHODS: A total of 344 IgG4-SC patients were enrolled in this study. As controls, 245, 110, and 149 patients with pancreatic cancer, primary sclerosing cholangitis, and CC, respectively, were enrolled. IgG4-SC patients were classified into three groups: type 1 (stenosis only in the lower part of the common bile duct), type 2 (stenosis diffusely distributed throughout the intrahepatic and extrahepatic bile ducts), and types 3 and 4 (stenosis in the hilar hepatic region) with 246, 56, and 42 patients, respectively. Serum IgG4 levels were compared, and the cut-offs were established. RESULTS: The cut-off obtained from receiver operator characteristic curves showed similar sensitivity and specificity to that of 135 mg/dL when all IgG4-SC and controls were compared. However, a new cut-off value was established when subgroups of IgG4-SC and controls were compared. A cut-off of 182 mg/dL can increase the specificity to 96.6% (4.7% increase) for distinguishing types 3 and 4 IgG4-SC from CC. A cut-off of 207 mg/dL might be useful for completely distinguishing types 3 and 4 IgG4-SC from all CC. CONCLUSIONS: Serum IgG4 is useful for the differential diagnosis of IgG4-SC and controls.

Comparison of carbon dioxide and air insufflation use by non-expert endoscopists during endoscopic retrograde cholangiopancreatography.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is subject to several complications that include a lengthy procedure time, technical difficulty, and active bowel movement induced by air insufflation. In ERCP carried out by non-expert endoscopists who are prone to excessive luminal insufflation, insufflation with carbon dioxide (CO2 ) may provide better and safer outcomes. We aimed to assess the efficacy and safety of CO2 insufflation during ERCP by non-expert endoscopists. METHODS: This study included 208 consecutive patients who received ERCP, excluding those in poor general health or with obstructive lung disease. The first operator for each patient was a non-expert endoscopist having done 50 or fewer ERCP procedures. Primary outcomes were the changes in cardiopulmonary state during ERCP. Secondary outcomes were ERCP complications. We designed a single-center, randomized, prospective, double-blind, controlled trial with CO2 and air insufflation during ERCP. RESULTS: CO2 insufflation did not affect overall procedure progression or results. A positive correlation was observed between procedure time and change in maximal systolic blood pressure from baseline among patients in the air insufflation group, but not in the CO2 insufflation group (correlation coefficient 0.408 vs 0.114, change in the maximal systolic blood pressure from baseline +4.2 vs+1.2 mmHg/10 min). This was consistent with our findings in patients treated by the first operator alone. The occurrence rate of post-ERCP pancreatitis tended to be lower in the CO2 group than the air group (4/102 [3.9%]vs 0/106 [0%], P = 0.056). CONCLUSIONS: CO2 insufflation during ERCP by non-expert endoscopists is recommended from the standpoints of efficacy and safety.

Medullary carcinoma of the ampulla has distinct clinicopathologic characteristics including common association with microsatellite instability and PD-L1 expression.

Medullary carcinomas have not yet been fully characterized in the ampulla. Here, 359 ampullary carcinomas (ACs) were reviewed and 11 medullary-type carcinomas (3%) were found and analyzed. In addition to the diagnostic medullary pattern, 6 showed focal mucinous and 8 had focal abortive gland-like formations. They occurred in younger patients (57 versus 65 y; P = .02), had larger invasion size (mean, 3.2 versus 1.9 cm; P = .01), formed nodular polypoid or plaque-like tumors, and often lacked preinvasive component. In addition to the lymphoplasmacytic infiltrates, they also had prominent eosinophils in 5 of 11 cases. Eight were papilla Vateri-NOS (not otherwise specified) tumors, 2 were ampullary-duodenal origin, 1 had a minor intra-ampullary papillary tubular neoplasm component, and none were ampullary-ductal. Although they had pushing-border infiltration, perineural and vascular invasion was common. They were strongly associated with DNA mismatch repair (MMR) protein deficient (7/11, 64%). The 5-yr survival rate (53%) appeared to be comparable with, and perhaps even better than that of nonmedullary ACs (47%), although this did not reach statistical significance (P = .47). Programmed cell death ligand-1 (PD-L1) expression levels were assessed in 8, and all 4 that were MMR deficient were positive both by combined positive score (CPS) ≥1 and tumor proportion score (TPS) ≥1, and of the 4 MMR proficient cases, 3 were positive by CPS; 2 by TPS. Overall, only 1 of the 8 available for analysis failed to show PD-L1 positivity by CPS. In contrast, nonmedullary MMR-deficient carcinomas expressed PD-L1 in only 33% of tumors by CPS, and none by TPS. One medullary carcinoma was also EBV associated. Unlike 'medullary carcinomas' of the kidney, INI1 was retained in all 8 cases tested. In conclusion, medullary carcinomas are 3% of ACs, have a strong association with MMR-D, and may be less aggressive despite their larger size. PD-L1 expression appears to be closely associated with medullary ACs regardless of MMR status, and thus targeted therapies can be considered for all medullary carcinomas of this site.

Extramedullary hematopoiesis in gastric wall under early gastric cancer in a man with a myeloproliferative disorder: a case report.

Extramedullary hematopoiesis (EMH) is the proliferation of hematopoietic stem cells outside the bone marrow and often observed in the liver, spleen in association with myeloproliferative disorders. On the other hand, EMH in the gastric wall is extremely rare. We report a rare case of EMH foci coexisting with early gastric cancer, which resulted in severe gastrointestinal bleeding. A 70-year-old male was diagnosed with myelofibrosis 4 years ago and visited our emergency room with a complaint of hematemesis and tarry stools. Upper gastrointestinal endoscopy revealed three early-stage gastric cancers in the lower gastric body and antrum, and biopsy was performed. Persistent bleeding at the biopsy site of the hypogastric lesion led to the consideration of surgical intervention. An open distal gastrectomy was performed. Postoperative histopathological examination revealed the tumor of the lower gastric body had EMH foci associated with myelofibrosis.

[Annular pancreas with high confluence of pancreaticobiliary ducts in an adult].

A man in his 80's was admitted complaining of epigastralgia, and acute pancreatitis was diagnosed. Abdominal CT and MRI showed enlargement of the pancreatic head encircling the descending part of the duodenum and a duodenal diverticulum. Endoscopic retrograde cholangio-pancreatography (ERCP) revealed annular pancreas and high confluence of pancreaticobiliary ducts. Annular pancreas had been reported to have associated with a broad spectrum of pancreatic anomalies, few cases of annular pancreas coexisting with high confluence of pancreaticobiliary ducts, or pancreaticobiliary maljunction have been reported. Combination of both anomalies was interesting from the view point of embryology. We report a rare case of annular pancreas with high confluence of pancreaticobiliary ducts.

Impact of DNA double-strand breaks on pancreaticobiliary maljunction carcinogenesis.

BACKGROUND: Pancreaticobiliary maljunction (PBM) is a condition characterized by chronic inflammation due to refluxed pancreatic juice into the biliary tract that is associated with an elevated risk of biliary tract cancer. DNA double-strand breaks (DSBs) are considered the most serious form of DNA damage. DSBs are provoked by inflammatory cell damage and are recognized as an important oncogenic event in several cancers. This study used γ-H2AX, an established marker of DSB formation, to evaluate the impact of DNA damage on carcinogenesis in PBM. METHODS: We investigated γ-H2AX expression immunohistochemically in gallbladder epithelium samples obtained from 71 PBM cases and 19 control cases. RESULTS: Fourteen PBM cases with gallbladder adenocarcinoma were evaluated at non-neoplastic regions. A wide range of nuclear γ-H2AX staining was detected in all PBM and control specimens. γ-H2AX expression was significantly higher in PBM cases versus controls (median γ-H2AX-positive proportion: 14.4 % vs. 4.4 %, p = 0.001). Among the PBM cases, γ-H2AX expression was significantly higher in patients with carcinoma than in those without (median γ-H2AX-positive proportion: 21.4 % vs. 11.0 %, p = 0.031). CONCLUSIONS: DSBs occurred significantly more abundantly in the PBM gallbladder mucosa, especially in the context of cancer, indicating an involvement in PBM-related carcinogenesis.

Evaluation and Pathologic Classification of Choledochal Cysts: Clinicopathologic Analysis of 84 Cases From the West.

Choledochal cyst (CC) is believed to be a mostly Asian disorder. As a clinically defined entity, its pathologic correlates are poorly characterized. Eighty-four resected CCs from the West were reanalyzed. After applying established Japanese criteria, 9/66 with available imaging were disqualified and 10/39 with preoperative cyst typing had to be recategorized. None had been diagnosed with, or evaluated for, pancreatobiliary maljunction, but on retrospective analysis of radiologic images, 12/66 were found to have pancreatobiliary maljunction. The clinical findings were: F/M=5.7; mean age, 48; most (77%) presented with abdominal pain; mean size, 2.9 cm; choledocholithiasis 11%. Gross/histologic examination revealed 3 distinct pathology-based categories: (I) Cystic dilatation of native ducts (81%). (II) Double bile duct (13%), almost all of which were found in women (10/11); all were diagnosed by pathologic examination, and not preoperative diagnosis. (III) Gastrointestinal (GI) duplication type (6%). Microscopic findings of the entire cohort included mucosal-predominant lymphoplasmacytic inflammation (50%), follicular cholangitis (7%), mucosal hyperplasia (43%; 13% with papillae), intestinal metaplasia (10%), BilIN-like hyperplasia (17%), erosion/ulceration (13%), and severe dysplasia-mimicking atypia including "detachment atypia" and micropapillary degeneration (11%). Carcinomatous changes were seen in 14 cases (17%) (high-grade dysplasia/carcinoma in situ in 7, intraductal papillary neoplasm 1, and invasive carcinoma 6); and 13/14 of these occurred in pathologic category I, all with cyst size >1 cm. In conclusion, diagnostic imaging guidelines used in Asia are not routinely used (but should be adopted) in the West. Pathologically, cases designated as CC are classifiable in 3 groups: category 1 (dilated native duct type), more prone to carcinomatous change; category 2, double-duct phenomenon (all but 1 being female in this study); and category 3, GI-type duplication. Overall, 17% of CCs show carcinomatous change (50% of them invasive). CC specimens should be carefully examined with this classification and submitted entirely for assessment of at-risk mucosa and cancerous transformation.

T2 gallbladder cancer shows substantial survival variation between continents and this is not due to histopathologic criteria or pathologic sampling differences.

Published data on survival of T2 gallbladder carcinoma (GBC) from different countries show a wide range of 5-year survival rates from 30-> 70%. Recently, studies have demonstrated substantial variation between countries in terms of their approach to sampling gallbladders, and furthermore, that pathologists from different continents apply highly variable criteria in determining stage of invasion in this organ. These findings raised the question of whether these variations in pathologic evaluation could account for the vastly different survival rates of T2 GBC reported in the literature. In this study, survival of 316 GBCs from three countries (Chile n = 137, South Korea n = 105, USA n = 74), all adequately sampled (with a minimum of five tumor sections examined) and histopathologically verified as pT2 (after consensus examination by expert pathologists from three continents), was analyzed. Chilean patients had a significantly worse prognosis based on 5-year all-cause mortality (HR: 1.89, 95% CI: 1.27-2.83, p = 0.002) and disease-specific mortality (HR: 2.41, 95% CI: 1.51-3.84, p < 0.001), compared to their South Korean counterparts, even when controlled for age and sex. Comparing the USA to South Korea, the survival differences in all-cause mortality (HR: 1.75, 95% CI: 1.12-2.75, p = 0.015) and disease-specific mortality (HR: 1.94, 95% CI: 1.14-3.31, p = 0.015) were also pronounced. The 3-year disease-specific survival rates in South Korea, the USA, and Chile were 75%, 65%, and 55%, respectively, the 5-year disease-specific survival rates were 60%, 50%, and 50%, respectively, and the overall 5-year survival rates were 55%, 45%, and 35%, respectively. In conclusion, the survival of true T2 GBC in properly classified cases is neither as good nor as bad as previously documented in the literature and shows notable geographic differences even in well-sampled cases with consensus histopathologic criteria. Future studies should focus on other potential reasons including biologic, etiopathogenetic, management-related, populational, or healthcare practice-related factors that may influence the survival differences of T2 GBC in different regions.