Since the approval of the anti-PD-1 antibody, nivolumab, for malignant melanoma in 2014, clinical development of immune checkpoint inhibitors (ICIs) has rapidly advanced, and the standard chemotherapy regimen has been successively replaced by ICI-based regimens. In biliary tract cancer, two phase III trials (TOPAZ-1 and KEYNOTE-966) demonstrated the efficacy of ICIs in combination with gemcitabine plus cisplatin (GC), and CG plus ICI has been established as the new standard chemotherapy regimen. On the other hand, management of immune-related adverse events (irAEs) is required when administering ICI-based regimen. Although the frequency of grade 3 or higher irAEs reported in phase III clinical trials is not high (<8%), the frequency of irAEs is expected to be higher in daily clinical practice, making the proper management of irAEs in ICI therapy clinically relevant.

In Japan, the standard treatment for resectable perihilar bile duct cancer is radical surgery and adjuvant chemotherapy with S1. To determine if a tumor is resectable, we must evaluate both host and tumor factors. In particular, it is essential to assess tumor progression and confirm safety. Resection of perihilar cholangiocarcinoma involves different dissection lines of the artery, portal vein, and bile duct. Surgical planning and execution are crucial. Postoperative mortality also tends to be high. Drainage and close observation of blood flow can help avoid serious complications. This includes arterial, portal, and venous flow. Treatment options for unresectable biliary tract cancer have increased in recent years. They are also looking at conversion resection for patients who respond well to these treatments over time. We must generalize the know-how from high-volume centers. This is to make the standard treatment of perihilar cholangiocarcinoma safe and effective.

Critically watching the investigators by society is getting more and more severe. When the ethical misconducts are revealed, published papers are retracted and posted on the internet. The Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Agency for Medical Research and Development (AMED) have published ethical guidelines, and the Japanese Medical Association has published guidelines for editing medical journals on their website. Research misconducts in were fabrication, falsification and plagiarism, while publication misconducts were duplicate submissions/publications, salami publications, and predatory journals. If you have any concerns about the misconducts in submission, you should describe them in the cover letter for the judgement of editorial board. Recently, the criteria of the authorship were clarified and the misconducts based on the criteria are gift, guest and ghost authorship. Scientists should recognize the responsibility to society in our research activity including the publication and try not to disappoint people.

The selection criteria between ERCP and Interventional-EUS (I-EUS) for biliary disease with surgically altered anatomy (SAA) have not yet been clarified.

In this study, we retrospectively reviewed the endoscopic results of the most recent 5-year period in patients with SAA without biliary reconstruction.

ERCP was performed in 67 cases and I-EUS in 14 cases.

The success rates for ERCP and I-EUS were 83.6% and 92.9%, and the adverse event rates were 11.9% and 7.1%, with no significant differences between them.

The median total procedure time was 105 minutes for ERCPs and 51 minutes for I-EUS, with significantly shorter results for I-EUS.

I-EUS showed comparable success rate and safety to ERCP for biliary disease in SAA without biliary reconstruction, and also showed an advantage of shorter procedure time.

We investigated the differences among patients with distal bile duct cancer with severe pancreatic invasion and were preoperatively diagnosed with pancreatic head cancer (Pre-PDAC group), patients with typical distal bile duct cancer (BDC group), and patients with pancreatic head cancer (PDAC group). Among 69 patients with distal bile duct cancer, 15 (21.7%) did not undergo surgical resection, and 54 (78.3%) underwent pancreaticoduodenectomy. Among the resected cases, 9 (16.7%) were classified as Pre-PDAC. The median survival time (MST) in the Pre-PDAC group was 20.9 months, significantly poorer than 106.8 months in the BDC group. No significant difference in MST was observed between the non-resected group (12.0 months), the Pre-PDAC group (20.9 months), and the PDAC group (32.9 months). The 2-year relapse-free survival rate was significantly lower in the Pre-PDAC group (25.0%) than in the BDC group (60.0%), and liver metastasis was frequently observed upon recurrence.

Five years have passed since cancer genome profiling (CGP) tests were approved for public insurance coverage in June 2019. The landscape of CGP tests has changed, and five types of CGP tests, including liquid biopsy using blood samples, are now available. Since the prevalence of druggable variants are high in biliary tract cancer, European Society for Medical Oncology (ESMO) recommends routine CGP test for unresectable biliary tract cancer. Currently, six biomarkers (FGFR fusion gene, MSI-H, BRAF V600E, TMB-H, NTRK fusion gene, and RET fusion gene) and matched drugs covered by insurance are available for biliary tract cancer in Japan, and more drugs targeting druggable variants are expected to enter daily clinical practice in the near future.

Recent advancements in endoscopic ultrasound (EUS) technology and devices have led to the increased adoption of EUS-guided biliary drainage (EUS-BD) and EUS-guided fine-needle aspiration/biopsy (EUS-FNA/B) for biliary diseases. EUS-BD, in particular, is proving effective even in cases where ERCP is challenging, and is expected to become a standard treatment for biliary drainage alongside ERCP. This review introduces the classification and terminology of EUS-related procedures proposed by the Japan Gastroenterological Endoscopy Society, categorizing them into five distinct groups based on the latest findings. The focus then shifts to EUS-BD, highlighting key technical considerations and new devices to manage complications. The review also discusses the "Revised Tokyo Criteria 2024," which proposes standardized evaluation methods for endoscopic biliary drainage, with a particular emphasis on EUS-BD. By unifying terminology and evaluation criteria across studies, the review aims to facilitate data comparison and further advance EUS-related procedures in the treatment of biliary diseases. Standardization of procedure terminology and evaluation criteria will facilitate comparison of data across studies and should further advance EUS-related procedures in biliary disease.

The patient was a 66-year-old woman. A gallbladder polyp was detected 11 years ago and was followed up, but it showed a tendency to increase in size. An endoscopic ultrasonography revealed a papillary lesion 11mm in diameter with high echo spots at the neck of the gallbladder, and a cholesterol polyp was suspected. Since the size of the lesion was more than 10mm and malignancy could not be ruled out, a laparoscopic cholecystectomy was performed. A 10 × 7 × 5mm stalked, protruding lesion was found at the neck of the gallbladder. Histopathological examination revealed a papillary growth of columnar epithelium centered on a narrow vascular fibrous stroma. The nuclei were spindle-shaped and arranged in the basement membrane, and the lesion was diagnosed as intracholecystic papillary neoplasm (ICPN) with low-grade dysplasia. ICPN is a precancerous lesion and many cases are accompanied by invasive carcinoma. ICPN without carcinoma like our case is extremely rare and is difficult to differentiate between malignant and benign disease.

A 73-year-old man underwent laparoscopic cholecystectomy for cholecystitis caused by gallstones 4 years ago. During the examination of a colon tumor, PET-CT revealed an accumulation of FDG in the surgical site of the gallbladder. Abdominal CT revealed a soft tissue shadow corresponding to the residual cystic duct from the metal clip at the closed end of the cystic duct to the bile duct. The mass had invaded S5 of the liver. Suspecting residual cystic duct carcinoma, extrahepatic bile duct resection, S5 partial resection, and lymph node dissection were performed. A cross section revealed a 22 × 20mm mucinous mass with a relatively clear border to the liver. The tumor was diagnosed as mucinous carcinoma of the residual cystic duct. The patient has been alive without recurrence for 5 years with postoperative radiotherapy and oral administration of S-1.

The patient was an 82-year-old man. He was presented with abdominal discomfort. Abdominal sonography revealed a mass in the lateral segment of the liver. Contrast-enhanced computed tomography (CT) exposed a 40mm cystic lesion with an internal nodule. A portion of the liver parenchyma contiguous to the nodule showed a delayed contrast effect on contrast-enhanced CT and a defect on contrast-enhanced ultrasonography with Kupffer imaging. Magnetic Resonance Imaging (MRI) exhibited low signal intensity on T1-weighted images, high signal intensity on T2-weighted images with restricted diffusion, and FDG-PET indicated accumulation in the same area. A preoperative diagnosis of cystic adenocarcinoma of the liver was made. Consequently, laparoscopic surgery was performed. The postoperative pathological analysis confirmed type 1 and classified it into a biliopancreatic subtype with invasive IPNB. One year later, there was a recurrence of lymph node metastasis, leading to surgical intervention. Subsequently, one-year post-reoperation, the patient is presently undergoing regular outpatient follow-up with no signs of recurrence. Notably, recent pathological investigations of IPNB have delineated four subtypes and two classifications. We report a rare case of type 1 biliopancreatic IPNB of peripheral intrahepatic origin with stromal infiltration and a characteristic case with a well-defined infiltrated area on imaging examination.

A 75-year-old woman developed portal vein thrombosis following a laparoscopic cholecystectomy for a gallbladder adenoma and was managed with anticoagulant therapy. Approximately two months post-surgery, she presented to the emergency department with hematemesis. Contrast-enhanced CT revealed no active bleeding, but cavernous transformation was noted. EGD showed minor bleeding from the duodenal papilla, and ERCP was performed for suspected haemobilia. Upon insertion of a contrast catheter into the bile duct, significant hemorrhage was observed. Cholangiography identified collateral vessels around the bile duct, leading to a diagnosis of bleeding from common bile duct varices.

Hemostasis was achieved by placing a fully-covered self-expandable metal stent to compress the varices. Although rare, common bile duct variceal bleeding should be considered in patients with portal hypertension.

The patient is a 15-year-old male. He has had recurrent abdominal pain for almost 10 years. Blood tests revealed elevated hepatobiliary enzymes and inflammatory reactions, but the cause could not be found. Abdominal ultrasonography performed immediately after the onset of abdominal pain revealed enlarged gallbladder, stenosis of the adjacent right hepatic duct, and dilatation of the intrahepatic bile duct. Magnetic resonance cholangiopancreatography revealed intrahepatic gallbladder and cystic duct maljunction. Endoscopic retrograde cholangiopancreatography showed that the cystic duct joined near the bifurcation of anterior and posterior branch, and that the gallbladder caused compression and stenosis of the right hepatic duct. It was revealed that biliary congestion due to obstruction of hepatic duct more centrally than at the junction. Laparoscopic cholecystectomy was performed. Cholangiography with indocyanine green fluorescence was performed to ensure the safety.

A female who was referred to our hospital due to jaundice. CT and MRCP revealed extensive tumors from the intrahepatic bile ducts to the distal bile duct. In POCS examination, the tumor in the hilar region appeared as an intraductal tumor thrombus, and based on the EOB-MRI findings, it was determined to be a tumor localized within the bile duct. The patient underwent right hepatectomy. Pathological examination showed that the tumor proliferated in a cast-like manner. The tumor cells proliferated in a cribriform pattern, were negative for MUC1, MUC5AC, and S100P, but showed positive CRP staining, leading to a diagnosis of Type 2 IPNB. This tumor presented a rare pattern of intraductal growth. It is believed that further accumulation of similar cases will clarify its characteristics.

The bile ducts are anatomically located in close proximity to the hepatic artery and portal vein, and advanced biliary tract cancers are likely to involve these hepatic inflow vessels. In perihilar cholangiocarcinoma surgery combined with portal vein resection, forms of resection and reconstruction of the portal vein varies depending on the extent and location of the portal vein involvement. In most of cases, segmental resection followed by direct end-to-end anastomosis is applied; however, in cases where direct anastomosis is unfeasible, reconstruction utilizing grafts is considered. Autologous venous grafts are typically employed, with the external iliac vein being the preferred choice due to its optimal characteristics. The paper focuses on the technical aspects of portal vein interpositional graft reconstruction for perihilar cholangiocarcinoma.