BACKGROUND: Hydatid disease, also known as echinococcosis, is a zoonotic parasitic infection caused by the larvae of the Echinococcus tapeworm. It is endemic in various regions worldwide, particularly in rural areas of countries in southern South America, Central Asia, China, parts of Africa, the Mediterranean, and parts of the Middle East. The disease primarily affects the liver (60-70% of cases) and the lungs (10-25% of cases), but it can involve any organ, including the brain, bones, and rarely the pelvic region, as seen in our case report. Hydatid disease typically follows an asymptomatic course in the early stages of the primary infection and may remain so potentially for years or even permanently. If symptoms occur, they depend on various factors, such as the number, size, and location among other factors. Typically, hydatid disease presents with nonspecific symptoms. Common symptoms include abdominal pain, hepatomegaly, as well as anaphylaxis in case of cyst rupture. Extrahepatic intra-abdominal isolated hydatic cyst is a rare finding (6-11%).
METHODS: In our case, a 70 year-old Asian white male presented with right thigh pain radiating to the lower leg, which is an atypical presentation for an extrahepatic intraabdominal hydatid cyst. Primary intraabdominal hydatid cysts involving the pelvic region are relatively rare, and such cases pose diagnostic and management challenges.
CONCLUSIONS: This case report underscores the challenges in diagnosing and managing extrahepatic intraabdominal hydatid cysts, particularly in atypical presentations. A combination of clinical evaluation, serological studies, and imaging techniques facilitates accurate diagnosis.

BACKGROUND: A comprehensive understanding of the extrahepatic bile duct anatomy is vital to guide surgical procedures and perform endoscopic retrograde cholangiography. Anatomical irregularities within the extrahepatic bile duct may increase susceptibility to bile duct stones.
OBJECTIVE: To investigate the anatomical risk factors associated with extrahepatic bile ducts in patients diagnosed with choledocholithiasis, with a specific focus on preventing stone recurrence after surgical intervention and endoscopic lithotomy.
METHODS: We retrospectively analyzed the medical records of 124 patients without choledocholithiasis and 108 with confirmed choledocholithiasis who underwent magnetic resonance cholangiopancreatography examinations at our center between January 2022 and October 2022. Logistic regression analyses were conducted to identify the anatomical risk factors influencing the incidence of common bile duct stones.
RESULTS: Multivariate logistic regression analysis revealed that several factors independently contributed to choledocholithiasis risk. Significant independent risk factors for choledocholithiasis were diameter of the common hepatic [adjusted odds ratio (aOR) = 1.43, 95% confidence interval (CI): 1.07-1.92, adjusted P value = 0.016] and common bile (aOR = 1.68, 95%CI: 1.27-2.23, adjusted P value < 0.001) ducts, length of the common hepatic duct (aOR = 0.92, 95%CI: 0.84-0.99, adjusted P value = 0.034), and angle of the common bile duct (aOR = 0.92, 95%CI: 0.89-0.95, adjusted P value < 0.001).
CONCLUSIONS: The anatomical features of the extrahepatic bile duct were directly associated with choledocholithiasis risk. Key risk factors include an enlarged diameter of the common hepatic and bile ducts, a shorter length of the common hepatic duct, and a reduced angle of the common bile duct.

BACKGROUND: Hepatocellular carcinoma (HCC) is a primary liver tumor generally diagnosed based on radiographic findings. Metastatic disease is typically associated with increased tumor diameter, multifocality, and vascular invasion. We report a case of a patient who presented with extrahepatic HCC metastasis to a portocaval lymph node with occult hepatic primary on computed tomography (CT). We review the literature for cases of extrahepatic HCC presentation without known hepatic lesions and discuss strategies to differentiate between metastatic and ectopic HCC.
METHODS: A 67-year-old male with remotely treated hepatis C was referred for evaluation of an enlarging portocaval, mixed cystic-solid mass. Serial CT evaluations demonstrated steatosis, but no cirrhosis or liver lesions. Endoscopic ultrasound demonstrated a normal-appearing pancreas, biliary tree, and liver. Fine needle aspiration yielded atypical cells. The differential diagnosis included duodenal or pancreatic cyst, lymphoproliferative cyst, stromal or mesenchymal lesions, nodal involvement from gastrointestinal or hematologic malignancy, or duodenal gastro-intestinal stromal tumor. After review by a multidisciplinary tumor board, the patient underwent open surgical resection of a 5.2 cm × 5.5 cm retroperitoneal mass with pathology consistent with moderately-differentiated HCC. Magnetic resonance imaging (MRI) subsequently demonstrated a 1.2 cm segment VIII hepatic lesion with late arterial enhancement, fatty sparing, and intrinsic T1 hyperintensity. Alpha fetoprotein was 23.3 ng/mL. The patient was diagnosed with HCC with portocaval nodal involvement. Review: We surveyed the literature for HCC presenting as extrahepatic masses without history of concurrent or prior intrahepatic HCC. We identified 18 cases of extrahepatic HCC ultimately found to represent metastatic lesions, and 30 cases of extrahepatic HCC found to be primary, ectopic HCC.
CONCLUSIONS: Hepatocellular carcinoma can seldomly present with extrahepatic metastasis in the setting of occult primary. In patients with risk factors for HCC and lesions suspicious for metastatic disease, MRI may be integral to identifying small hepatic lesions and differentiating from ectopic HCC. Tumor markers may also have utility in establishing the diagnosis.

UNASSIGNED: Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021.
UNASSIGNED: Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop.
UNASSIGNED: In November 2021, the finalized draft was presented for public scrutiny during a formal hearing.
UNASSIGNED: The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

BACKGROUND: There are two sub-phenotypes of large-duct primary sclerosing cholangitis (PSC): isolated intrahepatic PSC (IIPSC) and extrahepatic disease with or without intrahepatic (extra/intrahepatic).
OBJECTIVE: This study examined the differences in outcomes in patients with IIPSC compared to extra/intrahepatic and small-duct PSC.
METHODS: Patients with PSC treated at our institution from 1998 to 2019 were investigated. Biochemistries, clinical events, and survival were assessed by chart review and National Death Index. Cox-proportional hazards were used to determine the risk of clinical outcomes based on biliary tract involvement.
RESULTS: Our cohort comprised 442 patients with large-duct PSC (57 had IIPSC, 385 had extra/intrahepatic PSC) and 23 with small-duct PSC. Median follow-up in the IIPSC group was not significantly different from the extra/intrahepatic group [7 vs. 6 years, P = 0.06]. Except for lower age (mean 37.9 vs. 43.0 years, P = 0.045), the IIPSC group was not different from the extra/intrahepatic. The IIPSC group had longer transplant-free survival (log-rank P = 0.001) with a significantly lower risk for liver transplantation (12% vs. 34%, P < 0.001). The IIPSC group had a lower risk of death or transplantation than the extra/intrahepatic PSC group [HR: 0.34, 95% CI: 0.17-0.67, P < 0.001]. No bile duct or gallbladder cancers developed in patients with IIPSC, compared to 24 in the extra/intrahepatic group. The clinical characteristics and outcomes of IIPSC were similar to 23 individuals with small-duct PSC.
CONCLUSIONS: Patients with IIPSC have a favorable prognosis similar to small-duct PSC. These data are important for counseling patients and designing therapeutic trials for PSC.

BACKGROUND: There is limited information regarding percutaneous transvenous coil embolization (PTCE) for single extrahepatic portosystemic shunt (PSS). This study aimed to describe the procedure and outcome of PTCE in dogs with a single extrahepatic PSS. Forty-two privately owned dogs were included in this study. All dogs were diagnosed with extrahepatic PSS by computed tomography (CT). Preoperative CT images were used to evaluate the diameter of the PSS for coil placement. A multipurpose balloon catheter was percutaneously inserted into the PSS via the jugular vein, and transvenous retrograde portography (TRP) and measurement of blood pressure in the PSS (pPSS) were performed during balloon inflation; one or more embolization coils were implanted via the catheter.
RESULTS: In most cases, preoperative median fasting and postprandial serum total bile acid (TBA) concentrations were high (fasting, 86.5 μmol/L [ 3.7-250.0 μmol/L]; postprandial, 165.5 μmol/L [ 1.5-565.0 μmol/L]). CT revealed that 30 dogs had left gastrophrenic shunt; eight had left gastroazygos shunt; and one each had left gastrocaval, splenocaval, splenophrenic, and left colocaval shunt. TRP revealed that intrahepatic portal vascularity was clearly detectable in all dogs. The median values of pPSS before and during the balloon occlusion were 4.8 mmHg [2.0-13.0 mmHg] and 8.6 mmHg [5.0-18.0 mmHg], respectively. The median number and diameter of coils used were 2 coils [1 - 5 coils] and 8.0 mm [4.0 - 12.0 mm], respectively. The median times of irradiation and PTCE were 9 min [4-26 min] and 40 min [23-75 min], respectively. The median fasting and postprandial TBAs significantly decreased to 8.2 μmol/L [0.3-45.1 μmol/L, n = 38, p = 0.0028] and 19.8 μmol/L [0.3-106.7 μmol/L, n = 38, p = 0.0018], respectively, approximately 1 month after PTCE. The clinical success rate of PTCE without requirement for a second surgery was 95.2% (40/42 dogs). During revision surgery, one dog underwent surgical ligation and, in another dog, an ameroid constrictor was placed.
CONCLUSIONS: PTCE was clinically effective in treating single extrahepatic PSS in dogs. Preoperative CT and TRP prior to PTCE might be clinically valuable for choosing the size of embolization coils, deciding the appropriate location of coil implantation, and estimating the number of coils to be implanted. PTCE is a promising alternative to conventional surgical procedures for single extrahepatic PSS in dogs.

Recombinant adeno-associated viral (AAV) vectors are the current benchmark for systemic delivery of gene therapies to multiple organs in vivo. Despite clinical successes, safe and effective gene delivery to extrahepatic tissues has proven challenging due to dose limiting toxicity arising from high liver uptake of AAV vectors. Deeper understanding of AAV structure, receptor biology, and pharmacology has enabled the design and engineering of liver-de-targeted capsids ushering in several new vector candidates. This next generation of AAVs offers significant promise for extrahepatic gene delivery to cardiovascular, musculoskeletal, and neurological tissues with improved safety profiles.

CYP1A1 is a cytochrome P450 family 1 enzyme that is mostly expressed in the extrahepatic tissues. To understand the CYP1A1 contribution to drug clearance in humans, we examined the in vitro-in vivo extrapolation (IVIVE) of intrinsic clearance (CLint) for a set of drugs that are in vitro CYP1A1 substrates. Despite being strong in vitro CYP1A1 substrates, 82% of drugs gave good IVIVE with predicted CLint within 2-3-fold of the observed values using human liver microsomes and hepatocytes, suggesting they were not in vivo CYP1A1 substrates due to the lack of extrahepatic contribution to CLint. Only three drugs (riluzole, melatonin and ramelteon) that are CYP1A2 substrates yielded significant underprediction of in vivo CLint up to 11-fold. The fold of CLint underprediction was linearly proportional to human recombinant CYP1A1 (rCYP1A1) CLint, indicating they were likely to be in vivo CYP1A1 substrates. Using these three substrates, a calibration curve can be developed to enable direct translation from in vitro rCYP1A1 CLint to in vivo extrahepatic contributions in humans. In vivo CYP1A1 substrates are planar and small, which is consistent with the structure of the active site. This is in contrast to the in vitro substrates, which include large and nonplanar molecules, suggesting rCYP1A1 is more accessible than what is in vivo. The impact of CYP1A1 on first-pass intestinal metabolism was also evaluated and shown to be minimal. This is the first study providing new insights on in vivo translation of CYP1A1 contributions to human clearance using in vitro rCYP1A1 data.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is one of the common causes of chronic liver disease globally. Obesity, metabolic diseases, and exposure to some environmental agents contribute to NAFLD. NAFLD is commonly considered a precursor for some types of cancers. Since the leading causes of death in people with NAFLD are cardiovascular disease and extrahepatic cancers, it is important to understand the mechanisms of the progression of NAFLD to control its progression and identify its association with extrahepatic cancers. Thus, this review aims to estimate the global prevalence of NAFLD in association with the risk of extrahepatic cancers.
OBJECTIVE: We aimed to determine the prevalence of various cancers in NAFLD patients and the association between NAFLD and cancer.
METHODS: We searched PubMed, ProQuest, Scopus, and Web of Science from database inception to March 2022 to identify eligible studies reporting the prevalence of NAFLD and the risk of incident cancers among adult individuals (aged ≥18 years). Data from selected studies were extracted, and meta-analysis was performed using random effects models to obtain the pooled prevalence with the 95% CI. The quality of the evidence was assessed with the Newcastle-Ottawa Scale.
RESULTS: We identified 11 studies that met our inclusion criteria, involving 222,523 adults and 3 types of cancer: hepatocellular carcinoma (HCC), breast cancer, and other types of extrahepatic cancer. The overall pooled prevalence of NAFLD and cancer was 26% (95% CI 16%-35%), while 25% of people had NAFLD and HCC (95% CI 7%-42%). NAFLD and breast cancer had the highest prevalence out of the 3 forms of cancer at 30% (95% CI 14%-45%), while the pooled prevalence for NAFLD and other cancers was 21% (95% CI 12%-31%).
CONCLUSIONS: The review suggests that people with NAFLD may be at an increased risk of cancer that might not affect not only the liver but also other organs, such as the breast and bile duct. The findings serve as important evidence for policymakers to evaluate and recommend measures to reduce the prevalence of NAFLD through lifestyle and environmental preventive approaches.
BACKGROUND: PROSPERO CRD42022321946; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=321946.

Bile acids (BAs) are natural ligands for several receptors modulating cell activities. BAs are synthesized via the classic (neutral) and alternative (acidic) pathways. The classic pathway is initiated by CYP7A1/Cyp7a1, converting cholesterol to 7α-hydroxycholesterol, while the alternative pathway starts with hydroxylation of the cholesterol side chain, producing an oxysterol. In addition to originating from the liver, BAs are reported to be synthesized in the brain. We aimed at determining if the placenta potentially represents an extrahepatic source of BAs. Therefore, the mRNAs coding for selected enzymes involved in the hepatic BA synthesis machinery were screened in human term and CD1 mouse late gestation placentas from healthy pregnancies. Additionally, data from murine placenta and brain tissue were compared to determine whether the BA synthetic machinery is comparable in these organs. We found that CYP7A1, CYP46A1, and BAAT mRNAs are lacking in the human placenta, while corresponding homologs were detected in the murine placenta. Conversely, Cyp8b1 and Hsd17b1 mRNAs were undetected in the murine placenta, but these enzymes were found in the human placenta. CYP39A1/Cyp39a1 and cholesterol 25-hydroxylase (CH25H/Ch25h) mRNA expression were detected in the placentas of both species. When comparing murine placentas and brains, Cyp8b1 and Hsd17b1 mRNAs were only detected in the brain. We conclude that BA synthesis-related genes are placentally expressed in a species-specific manner. The potential placentally synthesized BAs could serve as endocrine and autocrine stimuli, which may play a role in fetoplacental growth and adaptation.