Several years have passed since the clinical diagnostic criteria for IgG4-related sclerosing cholangitis 2012 were published. New findings and knowledge have accumulated since then. The Research Committees for IgG4-related Diseases and for Intractable Diseases of the Liver and Biliary Tract, in association with the Ministry of Health, Labor, and Welfare of Japan and the Japan Biliary Association, have established a working group consisting of researchers specializing in IgG4-SC and have drawn up new clinical diagnostic criteria for IgG4-SC 2020. The diagnosis of IgG4-SC is based on a combination of the following six criteria: (a) narrowing of the intra- or extrahepatic bile duct; (b) thickening of the bile duct wall; (c) serological findings; (d) pathological findings; (e) other organ involvement; and (f) effectiveness of steroid therapy. These new diagnostic criteria for IgG4-SC are useful in practice for general physicians and other non-specialists.

Gallbladder polyps are classified pathologically as either non-neoplastic or neoplastic. The majority of non-neoplastic polyps are cholesterol polyps, which are also termed hyperplastic polyps or fibrous polyps when the epithelium proliferates and the stroma becomes fibrotic in addition to a decrease of foam cells. Polyps that arise in the setting of inflammations include granulation tissue polyp, fibromyoglandular polyps and lymphoid polyps. Fibromyoglandular polyps are diagnosed as hyperplastic polyps, metaplastic polyps and fibrous polyps depending on findings in the epithelium or stroma. Neoplastic polyps include pyloric gland adenoma and intracytic papillary neoplasms (ICPN). Pyloric gland adenoma shows unique morphological features, and preferencially occurs in the gallbladder. ICPN was reported as a counterpart of pancreatic intraductal papillary mucinous neoplasms (IPMN) in the gallbladder, but the histological findings of ICPN are different from those of IPMN, and may also encompass lesions termed polypoid gallbladder carcinomas.

Laparoscopic cholecystectomy has become a standard procedure for various benign gallbladder diseases including cholecystolithiasis, and Japanese guidelines recommend bailout procedure for difficult laparoscopic cholecystectomy to avoid intraoperative bile duct injury. On the other hand, other minimally invasive operations using laparoscopic or robot-assisted approach cannot be performed in Japan because of delay in maintenance of insurance medical care system support. The reasons include the high-level difficulty of operation for malignant biliary diseases even in open approach, advances in endoscopic intervention using ERCP or EUS technique which lead unnecessity of surgical approach, and difficulty in wide spread in daily practice of laparoscopic operation for congenital biliary diseases which are good candidates for laparoscopic operation, because of their rarity. Expansion of the insurance application of robot-assisted operation, and introduction of laparoscopic operation for relatively early-stage biliary cancer are the pressing issues.

A 80-year-old man was diagnosed with autoimmune pancreatitis and IgG4-related sclerosing cholangitis in 201X. Endoscopic retrograde cholangiopancreatography (ERCP) showed a stricture of the lower common bile duct. we performed endoscopic biliary stenting (EBS), steroid therapy was started. The bile duct stricture and diffuse swelling of pancreas improved after administration of prednisolone (30mg daily). The prednisolone dose decreased gradually to 3mg daily. He was admitted to our hospital because of evaluation of total bilirubin, transaminase, alkaline phosphatase and γ-glutamyl transferase. ERCP showed a stricture of the upper common bile duct differing from the findings in the first attack. We performed EBS and the prednisolone dose increased to 30mg daily again. The postoperative course is uneventful. In this case, the bile duct stricture relapsed at different sites in metachronous during steroid maintenance therapy. We present this case, with a review of the literature.

A patient who had underwent central bisectionectomy developed postoperative isolated bile leakages. ERC and PTC revealed a loss of the hilum with interruption of the left and right bile ducts as well as common bile duct (CBD). Furthermore, PTC revealed a biloma concomitant with peripheral bile ducts. To reconnect the biliary system, rendezvous technique was planned. PTBD was inserted from peripheral sides. The guide wire penetrated bluntly from peripheral duct into the biloma. Then, obstruction of CBD was also penetrated by guide wire under ERC. The guide wire from PTBD was grasped and pulled through duodenum. PTBD tube was inserted along to the guide wire and internal biliary drainage succeeded. We report a case of refractory peripheral bile leakage with complete hepatic hilum biliary strictures treated by a combined percutaneous-endoscopic rendezvous technique resulting in successful internal biliary drainage.

The subject was a 68-year-old female. Upon close examination, she was diagnosed with left-dominant Bismuth IV hilar cholangiocarcinoma. The left lobe had contracted due to occlusion of the portal left branch, while the anterior segmental branch of the right hepatic artery system was diagnosed as positive for segmental plexus infiltration. Although we considered resection of the left lobe and caudate lobe based on the estimated residual liver volume, because it requires combined resection of the anterior segment arterial branch, technical difficulties during reconstruction and potential ischemia in the anterior segment without performing reconstruction were a concern. We carried out coil embolization of the infiltration-positive site with a length of approximately 2cm at the anterior segment arterial branch prior to surgery. Resection of the hepatic left lobe and caudate lobe, resection of the extrahepatic bile duct, combined resection of the portal vein and reconstruction, and combined resection of the anterior segmental branch of the right hepatic artery were performed. A pathological diagnosis revealed pT2bN0, pStage II, and R0. Although anastomotic leakage occurred following surgery, she improved with conservative treatment. She has been followed up as an outpatient for 4 years and 5 months without recurrence. Following coil embolization of the anterior segment arterial branch prior to surgery for development of the intrahepatic collateral flow, we carried out left hepatectomy along with resection of the anterior segment arterial branch without reconstruction, resulting in a safe R0 resection.

The patient was a 70-year-old woman. In 20XX, left hepatic lobectomy, caudate lobectomy, and extrahepatic cholangectomy were performed, and she was pathologically diagnosed with intrahepatic cholangiocarcinoma with a positive margin, stage III (T4N0M0). We administered 4 courses of tegafur/gimeracil/oteracil (S-1). In 20XX+1, CT revealed multiple lung metastases. Gemcitabine and cisplatin therapy was administered 17 times. This was switched to gemcitabine and S-1 therapy; 20 courses were administered. The metastatic lung lesions tended to increase, and progressive disease was diagnosed. We then examined the surgical specimen and noticed high frequency microsatellite instability (MSI-H). We changed the treatment regimen to pembrolizumab in 20XX+3. CT after 4 courses of pembrolizumab revealed that the tumor had shrunk and a partial response was achieved. We propose that MSI testing be actively considered.

A 45-year-old man was referred to our hospital with dehydration due to frequent (7-8 times/day) diarrhea. Contrast-enhanced CT (CE-CT) revealed a cystic tumor measuring 20cm in diameter with roundly humping shape at the left lobe of the liver, and there were enhancing papillary lesions in the peripheral cystic tumor. In ERCP, a lot of serous bile juice was flowing out from Vater's papilla, and the ERC finding showed communication between the cystic lesion and the biliary duct branch. Extended left hepatic lobectomy was performed based on the diagnosis of intraductal papillary neoplasm of the bile duct (IPNB). On histopathological examination of the resected specimen, not papillary but tubular tumors existed in saccular dilated bile duct. Immunostaining findings were positive expression of MUC6, negative expression of MUC1 and MUC2, and weakly positive expressions of MUC5AC. The findings of tubular proliferative morphology and MUC staining did not match with IPNB or intraductal tubular papillary tumor; we therefore finally diagnosed intraductal tumor of the liver. After operation, the diarrhea symptom was improved and there was no recurrence during five years. We considered the large amount of serous bile juice produced from the tumor to be the cause of frequent diarrhea.

A 73-year-old woman with unresectable locally advanced pancreatic head cancer underwent chemoradiotherapy and chemotherapy after transpapillary biliary drainage with a plastic stent (PS). Three months later, we replaced with a self-expandable metallic stent (SEMS). However one year later, the SEMS had deviated into the duodenum, so we trimmed it with APC and placed PS in the SEMS. She continued to receive chemotherapy, but was admitted to the hospital with cholangitis two years and six months later. An emergency ERC revealed choledochoduodenal fistula on the oral side of the duodenal papilla in the descending portion of the duodenum, and exposed SEMS. We experienced a case of pancreatic head cancer with choledochoduodenal fistula caused by transpapillary SEMS. It was considered that the hepatoduodenal mesentery was shortened due to the bile duct mucosal damage caused by long-term implantation of SEMS and the tumor shrinkage due to multidisciplinary treatment, and SEMS eroded and penetrated the bile duct and duodenal wall. We report it with some consideration of the literature.

A 72-year-old man was referred to our department owing to the wall thickening of the gallbladder. CT and MRI revealed nodular and wall thickening lesions. EUS indicated tumor invasion to a layer of the subserosa. The bile juice cytology revealed adenocarcinoma. Extended cholecystectomy was performed; the resected specimen showed a mucosa with irregular surface and a separated fragment. Moreover, pathological findings of the fundus of the gallbladder revealed a tubular adenocarcinoma and a neuroendocrine carcinoma. Furthermore, the histological findings of a separated fragment revealed adenocarcinoma with sarcomatoid tissue. Finally, this lesion was diagnosed as a mixed neuroendocrine-non-neuroendocrine neoplasm with a sarcomatoid component. The complicated histological component may be the cause of the unique form.

A patient was 70-year-old man who had undergone gastrectomy for gastric cancer at 67 years of age.

He experienced severe diarrhea and a decrease in his hemoglobin level after undergoing adjuvant chemotherapy. Abdominal CT revealed thickness in the gallbladder wall and an indistinct margin between the gallbladder and the liver.

He was preoperatively diagnosed to have primary gallbladder cancer, according to the results of these examinations, and therefore an extended cholecystectomy with lymph node dissection was performed.

Histopathologically, the tumor of the resected gallbladder had the same immunostaining features as that of gastric cancer which had been resected, therefore, he was finally diagnosed to have gallbladder metastasis from the previous gastric cancer.

The patient has survived for 30 months since the resection of the gallbladder metastasis, without any sign of recurrence.

It is known that gallbladder metastasis from gastric cancer has a poor prognostic course. However, the surgical management of this disease may be able to achieve a long-term survival in cases without any other metastasis.

To our knowledge, there are no previous reports describing metachronous gallbladder metastasis from gastric cancer with a longer survival than that of our case.

Bouveret's syndrome is defined as gastric outlet obstruction following the impaction of a gallstone in the duodenum via a bilioenteric fistula. It is often treated surgically because the gallstone is large and difficult to treat endoscopically. In this study, we uncovered a case in which endoscopic electrohydraulic lithotripsy (EHL) was facilitated by using a biliary dilation catheter as outer probe. A 77-year-old woman presented to our hospital with a one-month history of anorexia and postprandial vomiting. Abdominal computed tomography revealed a 35-mm gallstone obstructing the proximal duodenum and a cholecystoduodenal fistula. We tried to remove the stone using mechanical lithotripsy; however, the procedure was unsuccessful. Subsequently, we tried to use EHL with biliary dilation catheter as outer probe, with which we have successfully removed the stone. The patient could avoid surgical treatment and the fistula closed spontaneously. We firmly believe that a biliary dilation catheter can be used as an outer for easier EHL.

Approaches for treating common bile duct stones are as follows: 1) Laparoscopic bile duct stone removal+cholecystectomy (single-stage), 2) Open cholecystectomy+choledocholithotomy (single-stage), 3) endoscopic stone removal+ (surgical) cholecystectomy (two-stage). And two-stage treatment is the most widely used. Although the number of cases is small, laparoscopic surgery is superior from the viewpoint of treatment efficiency and minimal invasiveness, and open surgery is fit for complicated or intractable cases.

The appropriate treatment should be selected from various options such as the approaches or instruments to be used. This paper describes the surgical treatment of bile duct stones, focusing on the single-stage procedure by laparoscopic surgery.