• Adenoma
• Gallbladder
• Polyps
• Risk factors
• Statistical model

• Humans
• Child, Preschool
• Retrospective Studies
• Gallbladder Neoplasms/diagnostic imaging
• Gallbladder Neoplasms/surgery
• Gallbladder Diseases/diagnostic imaging
• Gallbladder Diseases/surgery
• Ultrasonography/methods
• Adenoma/diagnostic imaging
• Adenoma/surgery
• Polyps/diagnostic imaging
• Polyps/surgery

• MUC5AC
• Mucin 5AC
• biliary carcinogenesis
• biliary tract cancer
• cholangiocarcinoma
• diagnosis
• extrahepatic
• gallbladder carcinoma
• intrahepatic
• prognosis

Lymphovascular invasion is a hallmark of malignant neoplasms, however the presence of benign epithelium within vessels has been reported in benign processes, albeit infrequently. The proposed mechanism to explain this phenomenon entails mechanical displacement of benign epithelium into the vascular spaces during surgical manipulation or diagnostic interventions. We report a case of numerous benign epithelial vascular emboli in a cholecystectomy specimen. A 29-year-old male presented with acute calculous cholecystitis. Surgery was delayed for several weeks due to COVID-19 infection. Histologic examination of the gallbladder showed subacute cholecystitis, widespread vascular epithelial emboli with associated fibrin deposition and bile embolism supporting an in vivo process. The epithelial emboli were localized in small veins and arterioles with D2–40−/CD31+/CD34+ endothelium. The displaced epithelium showed benign cytologic features, was negative for p53 expression, and had a Ki-67 labelling index like the benign background mucosa, supporting a benign process. There was no evidence of dysplasia or malignancy in the specimen after thorough sampling. Persistent inflammation, mucosal ulceration, transmural mucosal herniation (Rokitansky-Aschoff sinuses), and protracted surgical manipulation secondary to adhesive disease are favored to be the underlying causes of this unusual histologic finding. Although we presume an uneventful outcome, clinical follow up was recommended. COVID-19 infection likely contributed to this phenomenon by causing a delay in the surgical management.

• gallbladder polyp
• neoplastic polyp
• nomogram model
• preoperative diagnosis
• radiomics

• Gallbladder polyps
• Neoplastic polyp
• Nomogram model
• Preoperative diagnosis

• biliary
• cholangiocarcinoma
• malignant
• neoplasia
• subtypes

• Bile Duct Neoplasms/diagnosis
• Bile Duct Neoplasms/epidemiology
• Bile Ducts, Intrahepatic
• Cholangiocarcinoma/diagnosis
• Cholangiocarcinoma/epidemiology
• Humans

• KRAS
• extrahepatic biliary system
• hepatic ducts
• pyloric gland adenoma
• sequence

Intraductal papillary mucinous neoplasm of the bile duct (IPNB) is recognized as a precancerous lesion; however, both its pathogenesis and progression remain unclear. We present here a case of IPNB arising from the gallbladder accompanied by bile duct tumor thrombus in a 79-year-old female. The resected specimen revealed a tubulopapillary adenoma with no malignant cells. This case suggests that even in the absence of malignant cells, these tumors can behave as malignant tumors requiring aggressive treatment. Even if no malignant cells are present, intraepithelial neoplasms occurring in the ampullopancreatobiliary tract can behave as malignant tumors.

• Intraductal papillary mucinous neoplasm of the bile duct
• Tumor thrombi

• Adenoma/chemistry
• Adenoma/diagnostic imaging
• Adenoma/pathology
• Adenoma/surgery
• Aged
• Biomarkers, Tumor/analysis
• Biopsy
• Carcinoma in Situ/chemistry
• Carcinoma in Situ/diagnostic imaging
• Carcinoma in Situ/pathology
• Carcinoma in Situ/surgery
• Cholangiopancreatography, Endoscopic Retrograde
• Cholangiopancreatography, Magnetic Resonance
• Cholecystectomy
• Common Bile Duct Neoplasms/chemistry
• Common Bile Duct Neoplasms/diagnostic imaging
• Common Bile Duct Neoplasms/pathology
• Common Bile Duct Neoplasms/surgery
• Female
• Gallbladder Neoplasms/chemistry
• Gallbladder Neoplasms/diagnostic imaging
• Gallbladder Neoplasms/pathology
• Gallbladder Neoplasms/surgery
• Humans
• Immunohistochemistry
• Neoplasm Invasiveness
• Neoplasms, Cystic, Mucinous, and Serous/chemistry
• Neoplasms, Cystic, Mucinous, and Serous/diagnostic imaging
• Neoplasms, Cystic, Mucinous, and Serous/pathology
• Neoplasms, Cystic, Mucinous, and Serous/surgery
• Tomography, X-Ray Computed
• Treatment Outcome

Cholangiocarcinoma (CC) arising from the large intrahepatic bile ducts and extrahepatic hilar bile ducts share clinicopathological features and have been called hilar and perihilar CC as a group. However, “hilar and perihilar CC” are also used to refer exclusively to the intrahepatic hilar type CC or, more commonly, the extrahepatic hilar CC. Grossly, a major distinction can be made between papillary and non-papillary tumors. Histologically, most hilar CCs are well to moderately differentiated conventional type (biliary) carcinomas. Immunohistochemically, CK7, CK20, CEA and MUC1 are normally expressed, being MUC2 positive in less than 50% of cases. Two main premalignant lesions are known: biliary intraepithelial neoplasia (BilIN) and intraductal papillary neoplasm of the biliary tract (IPNB). IPNB includes the lesions previously named biliary papillomatosis and papillary carcinoma. A series of 29 resected hilar CC from our archives is reviewed. Most (82.8%) were conventional type adenocarcinomas, mostly well to moderately differentiated, although with a broad morphological spectrum; three cases exhibited a poorly differentiated cell component resembling signet ring cells. IPNB was observed in 5 (17.2%), four of them with an associated invasive carcinoma. A clear cell type carcinoma, an adenosquamous carcinoma and two gastric foveolar type carcinomas were observed.

• Cholangiocarcinoma
• Bile duct carcinoma
• Hilar cholangiocarcinoma
• Perihilar cholangiocarcinoma
• Klatskin tumor
• Extrahepatic bile duct carcinoma
• Hepatic hilum

Pyloric gland adenoma consists of closely packed pyloric-type glands lined by mucus-secreting cells. To date, approximately 230 cases have been reported, mostly of gastric localization with a tumour size up to 3.5 cm and a mean age of occurrence around 70 years. Adenocarcinoma develops in about 40% of cases and may be difficult to detect due to relatively mild nuclear atypia.

We present the first case of a pyloric gland adenoma of the cystic duct in a 62-year-old male patient and demonstrate the clinicopathologic characteristics, including radiographic, molecular, and cytogenetic findings. The 2 cm-tumour developed in the cystic duct and protruded into the hepatic and common bile duct. On microscopic examination, it displayed closely packed pyloric-type glands, and focal architectural distortion with mild nuclear atypia. Immunohistochemically, it expressed MUC1, MUC5AC, MUC6 and p53, but not MUC2 and CD10. The Ki67-proliferation index was 25%. Furthermore, high-grade intraepithelial neoplasia was observed in the surrounding bile duct. We detected chromosomal gains at 7p, 7q11q21, 15q, 16p, 20, losses at 6p23pter, 6q, 18, and amplifications at 1q and 6p21p22 in the pyloric gland adenoma by comparative genomic hybridization. A KRAS codon 12 mutation (c.35G>T; p.G12V) was detected in the pyloric gland adenoma and in the adjacent dysplasia by sequencing analysis. The diagnosis of pyloric gland adenoma was established with transition into well-differentiated adenocarcinoma and high-grade biliary intraepithelial neoplasia.

Pyloric gland adenoma evolving in the cystic duct is a rare differential diagnosis of obstructive bile duct tumours. Other premalignant bile duct lesions may be associated. Due to the risk of developing adenocarcinoma, surgical resection should be performed.