Caspase-4 has a role in cell division in epithelial cells through actin depolymerization.

In addition to its role in pyroptosis and inflammatory cytokine maturation, caspase-4 (CASP4) also contributes to the fusion of phagosomes with lysosomes and cell migration. However, its role in cell division remains elusive. In this study, we demonstrate that CASP4 is indispensable for proper cell division in epithelial cells. Knockout of CASP4 (CASP4 KO) in HepG2 cells led to delayed cell proliferation, increased cell size, and increased multinucleation. In mitosis, CASP4 KO cells showed multipolar spindles, asymmetric spindle positioning, and chromosome segregation errors, ultimately increasing DNA content and chromosome number. We also found that phalloidin, a marker of filamentous actin, increased in CASP4 KO cells owing to suppressed actin depolymerization. Moreover, the levels of actin polymerization-related proteins, including Rho-associated protein kinase1 (ROCK1), LIM kinase1 (LIMK1), and phosphorylated cofilin, significantly increased in CASP4 KO cells. These results suggest that CASP4 contributes to proper cell division through actin depolymerization.

Low skeletal muscle mass and high visceral adiposity are associated with recurrence of acute cholecystitis after conservative management: A propensity score-matched cohort study.

BACKGROUND: Recurrent acute cholecystitis (RAC) can occur after non-surgical treatment for acute cholecystitis (AC), and can be more severe in comparison to the first episode of AC. Low skeletal muscle mass or adiposity have various effects in several diseases. We aimed to clarify the relationship between RAC and body parameters. METHODS: Patients with AC who were treated at our hospital between January 2011 and March 2022 were enrolled. The psoas muscle mass and adipose tissue area at the third lumbar level were measured using computed tomography at the first episode of AC. The areas were divided by height to obtain the psoas muscle mass index (PMI) and subcutaneous/visceral adipose tissue index (SATI/VATI). According to median VATI, SATI and PMI values by sex, patients were divided into the high and low PMI groups. We performed propensity score matching to eliminate the baseline differences between the high PMI and low PMI groups and analyzed the cumulative incidence and predictors of RAC. RESULTS: The entire cohort was divided into the high PMI (n = 81) and low PMI (n = 80) groups. In the propensity score-matched cohort there were 57 patients in each group. In Kaplan-Meier analysis, the low PMI group and the high VATI group had a significantly higher cumulative incidence of RAC than their counterparts (log-rank P = 0.001 and 0.015, respectively). In a multivariate Cox regression analysis, the hazard ratios of low PMI and low VATI for RAC were 5.250 (95% confidence interval 1.083-25.450, P = 0.039) and 0.158 (95% confidence interval: 0.026-0.937, P = 0.042), respectively. CONCLUSIONS: Low skeletal muscle mass and high visceral adiposity were independent risk factors for RAC.

Impact of Interferon-Free Direct-Acting Antivirals on the Incidence of Extrahepatic Malignancies in Patients with Chronic Hepatitis C.

BACKGROUND: The incidence of extrahepatic malignancies (EHMs) after hepatitis C virus (HCV) eradication by interferon (IFN)-based and IFN-free direct-acting antivirals (DAAs) treatment remains unclear. AIMS: The aim was to evaluate the cumulative incidence of EHMs diagnosed for the first time after the antiviral treatments. METHODS: We analyzed a total 527 patients with chronic HCV infection and without prior history of any malignancies who achieved sustained virological response by antiviral treatments, including IFN-based (n = 242) or IFN-free DAAs (n = 285). The baseline predictors for EHM occurrence were analyzed using Cox regression analysis. RESULTS: Thirty-two patients were diagnosed with EHMs, 14 in IFN-based and 18 in IFN-free DAAs, respectively. The total duration of follow-up was 1,796 person-years in IFN-based and 823 person-years in IFN-free DAAs. The incidence of EHMs in IFN-based and IFN-free DAAs was 7.8 and 21.9 per 1,000 person-years, respectively. The cumulative incidence of EHMs was significantly higher in IFN-free DAAs than IFN-based (p = 0.002). IFN-free DAAs was a single independent predictor for incidence of EHMs (p = 0.012). As for gender, the incidence of EHMs was significantly higher in IFN-free DAAs only in the female cohort (p = 0.002). After propensity score matching, IFN-free DAAs was a single independent predictor for incidence of EHMs in the female patients (p = 0.045). CONCLUSIONS: The incidence of EHMs after HCV eradication is higher in IFN-free DAAs than IFN-based regimens, especially in female patients. We should carefully follow-up not only HCC but also EHMs after IFN-free DAAs regimens.

A Case of Successful Endoscopic Extraction of Common Bile Duct Stones After Closing a Duodenal Perforation Using Over-The-Scope Clip.

A 57-year-old man visited our hospital for acute cholangitis due to common bile duct (CBD) stones in March 2021. Biliary stenting was performed without any complications. The cholangitis improved rapidly. He was re-hospitalized to treat the CBD stones in May 2021. Although endoscopic retrograde cholangiopancreatography was performed, endoscopy caused a perforation of the duodenal bulb. We successfully performed endoscopic closure of the duodenal defect using an over-the-scope clip (OTSC®). Considering that mild CBD dilatation of 10 mm can carry an increased risk of stenosis after surgery, we decided to avoid surgery and perform a follow-up endoscopic treatment. He was re-hospitalized in July 2021. The endoscopy revealed OTSC® in the anterior wall of the duodenal bulb and complete healing of the perforation. We carefully advanced the scope to the second portion of the duodenum while avoiding OTSC®, and the ampulla of Vater was identified. We were then able to remove the stones without any complications. OTSC® was effective in closing a duodenal perforation and enabled us to carry out the retreatment safely and successfully.

Hepatic Cyst Infection Following Recurrent Biliary Obstruction in Polycystic Liver Disease.

An 89-year-old man with polycystic liver disease (PCLD) received uncovered self-expandable metallic stent (SEMS) placement above the papilla for malignant biliary obstruction caused by cholangiocarcinoma. He developed cholangitis ten months later due to SEMS occlusion caused by tumor ingrowth, and 2 plastic biliary stents were placed inside the SEMS across the papilla. Fever and right costal pain appeared two weeks after reintervention. Suspecting hepatic cyst infection based on imaging studies, percutaneous transhepatic cyst drainage was performed. Increased inflammatory cells and the presence of pathogens in the cyst fluid led to a definitive diagnosis of hepatic cyst infection. Following drainage, the hepatic cyst shrank with resolution of the symptoms. SEMS occlusive-related cholangitis or retrograde infection due to duodenal-biliary reflux after reintervention was considered as the cause of the hepatic cyst infection. Careful clinical and imaging evaluation should be performed in patients with PCLD undergone biliary stenting, because cyst infection may occur following stent occlusion or subsequent biliary reintervention.

A Case of Pancreatic Neuroendocrine Tumor G3 Which Responded Remarkably to Chemotherapy.

Pancreatic neuroendocrine carcinoma (NEC) as classified in the World Health Organization (WHO) 2010 was reclassified in the WHO 2017 as either neuroendocrine tumor (NET) G3 or NEC. An accurate diagnosis based on the WHO 2017 classification is important in order treating this disease appropriately. We report a case diagnosed as NET G3 that responded remarkably well to treatment with streptozocin. The patient would likely not have received the streptozocin treatment if she had been diagnosed with NEC. The WHO 2017 classification is reasonable for the treatment of advanced pancreatic neuroendocrine neoplasms.

Influence of gastroesophageal flap valve on esophageal variceal bleeding in patients with liver cirrhosis.

OBJECTIVES: Esophageal variceal bleeding can be fatal in patients with liver cirrhosis. The aim of this study was to investigate the relationship between gastroesophageal flap valve (GEFV) and esophageal variceal bleeding. METHODS: Subjects were cirrhotic patients with endoscopically diagnosed esophageal varices treated at our hospital between 2005 and 2019, excluding those with F3 form and red color (RC) signs at first endoscopy. Sixty-five patients with normal GEFV (Hill grade I or II) and 42 with abnormal GEFV (Hill grade III or IV) were enrolled. Propensity score matching eliminated the baseline differences, resulting in a sample size of 30 patients per cohort. The primary endpoint was esophageal variceal bleeding, and the secondary endpoint was variceal bleeding or appearance of RC sign. We analyzed the cumulative incidences and predictors of each endpoint. RESULTS: The 3-, 5-, and 10-year cumulative incidences of the primary endpoints were all 3.4% in the normal GEFV group, and 19.0%, 24.6% and 34.0% in the abnormal GEFV group, respectively (log-rank P = 0.011). Cumulative incidence of the secondary endpoint was 13.8%, 33.1% and 39.2% in the normal GEFV group, and 42.2%, 54.6% and 84.9% in the abnormal GEFV group, respectively (log-rank P = 0.001). In multivariate Cox regression analyses, hazard ratios of abnormal GEFV of the primary and secondary endpoints were 12.79 (95% confidence interval 1.331-122.8) and 3.600 (1.653-7.840), respectively. CONCLUSIONS: Abnormal GEFV was an independent risk factor for esophageal variceal bleeding and appearance of RC sign.

Correlation of hepatitis C virus-mediated endoplasmic reticulum stress with autophagic flux impairment and hepatocarcinogenesis.

Hepatitis C virus (HCV) infection has been known to use autophagy for its replication. However, the mechanisms by which HCV modulates autophagy remain controversial. We used HCV-Japanese fulminant hepatitis-1-infected Huh7 cells. HCV infection induced the accumulation of autophagosomes. Morphological analyses of monomeric red fluorescent protein (mRFP)-green fluorescent protein (GFP) tandem fluorescent-tagged LC3 transfection showed HCV infection impaired autophagic flux. Autophagosome-lysosome fusion assessed by transfection of mRFP- or GFP-LC3 and immunostaining of lysosomal-associated membrane protein 1 was inhibited by HCV infection. Decrease of HCV-induced endoplasmic reticulum (ER) stress by 4-phenylbutyric acid, a chemical chaperone, improved the HCV-mediated autophagic flux impairment. HCV infection-induced oxidative stress and subsequently DNA damage, but not apoptosis. Furthermore, HCV induced cytoprotective effects against the cellular stress by facilitating the formation of cytoplasmic inclusion bodies as shown by p62 expression and by modulating keratin protein expression and activated nuclear factor erythroid 2-related factor 2. HCV eradication by direct-acting antivirals improved autophagic flux, but DNA damage persisted. In conclusion, HCV-induced ER stress correlates with autophagic flux impairment. Decrease of ER stress is considered to be a promising therapeutic strategy for HCV-related chronic liver diseases. However, we should be aware that the risk of hepatocarcinogenesis remains even after HCV eradication.

Type 4B hereditary hemochromatosis due to heterozygous p.D157A mutation in SLC40A1 complicated with hypopituitarism.

Hemochromatosis is a clinical syndrome characterized by iron overload in various organs. We present here a case of type 4 hereditary hemochromatosis due to heterozygous mutation in SLC40A1 gene (p.D157A). SLC40A1 encodes ferroportin, a macromolecule only known as iron exporter from mammalian cells. He first presented symptoms correlated with hypopituitarism. Furthermore, marked hyperferritinemia and high transferrin saturation were revealed in combination with the findings of iron overload in the liver, spleen and pituitary gland by computed tomography and magnetic resonance imaging. Liver biopsy revealed iron deposition in both hepatocytes and Kupffer cells. SLC40A1 mutations are considered to cause wide heterogeneity by various ferroportin mutations. Thus, clinicopathological examinations seem to be very important for diagnosing phenotype of type 4 hemochromatosis in addition to the gene analysis. We diagnosed him as type 4B hereditary hemochromatosis (ferroportin-associated hemochromatosis) by the findings of high transferrin saturation and iron deposition in hepatocytes, and then started iron chelating treatment. We should suspect the possibility of hereditary hemochromatosis even in Japanese with severe iron overload. Although the same mutation in SLC40A1 gene (p.D157A) had been reported to cause "loss of function" phenotype, we considered that the mutation of our case caused "gain of function" phenotype.

Involvement of sarco/endoplasmic reticulum calcium ATPase-mediated calcium flux in the protective effect of oleic acid against lipotoxicity in hepatocytes.

Elevated free fatty acids, particularly saturated ones such as palmitic acid, may play an important role in the lipotoxic mechanism of nonalcoholic fatty liver disease (NAFLD). Saturated fatty acids induce autophagy dysfunction and endoplasmic reticulum (ER) stress leading to apoptosis in hepatocytes. However, unsaturated fatty acids, such as oleic acid, are nontoxic and can even prevent saturated fatty acid-induced toxicity in vitro. Although emerging evidence has suggested that ER calcium flux disruption in hepatocytes is involved in NAFLD pathogenesis, the roles of fatty acids in autophagy and ER calcium flux still remain unclear. We demonstrated that oleic acid ameliorated palmitic acid-induced autophagy arrest and ER stress in parallel with ER calcium depletion in hepatocytes. Moreover, we found that the effect of oleic acid against autophagy arrest was reversed by the pharmacological inhibition of sarcoplasmic reticulum Ca2+-ATPase (SERCA), which influxes calcium to ER. These data suggest that SERCA-mediated ER calcium flux is greatly involved in fatty acid-induced lipotoxicity in hepatocytes, and the prevention of ER calcium depletion may restore saturated fatty acid-induced autophagy arrest in hepatocytes.

Effect of direct-acting antivirals on platelet-associated immunoglobulin G and thrombocytopenia in hepatitis C virus-related chronic liver disease.

BACKGROUND & AIMS: Hepatitis C virus (HCV) infection has been known to cause various extrahepatic autoimmune disorders. The prevalence of platelet-associated immunoglobulin G (PA-IgG) has been high in patients with HCV infection. Because thrombocytopenia in HCV-related liver diseases is a notable problem, we performed prospective study on the effect of direct-acting antivirals (DAAs) treatment on PA-IgG and platelet count. METHODS: A total of 215 patients with HCV-related liver disease were enrolled in this study. The patients who discontinued DAAs or did not undergo adequate laboratory examinations and who did not achieve sustained virologic response were excluded and finally a total of 187 patients were investigated. RESULTS: A total of 171 patients (91.4%) were PA-IgG positive (>46 ng/107 cells) before starting DAAs (baseline). The PA-IgG level elevation was significantly correlated with higher liver inflammation and fibrosis markers (P < 0.05) and lower platelet count (P = 0.000019). The platelet count of the patients with low PA-IgG titer tended to be higher at baseline, end of treatment (EOT), and at 12 and 24 weeks after EOT. The platelet count increased at EOT (P < 0.05) and 24 weeks after EOT (P < 0.01). The PA-IgG levels were significantly decreased at EOT, 12 and 24 weeks after EOT (P < 0.01). Multiple regression analysis found that only platelet count at baseline was closely associated with negative conversion of PA-IgG at 24 weeks after EOT (P = 0.004). CONCLUSIONS: Eradication of HCV by DAAs treatment successfully decreased PA-IgG level and increased platelet count.

Zinc Attenuates the Cytotoxicity of Some Stimuli by Reducing Endoplasmic Reticulum Stress in Hepatocytes.

Zinc is an essential trace element and plays critical roles in cellular integrity and biological functions. Excess copper induced both oxidative stress and endoplasmic reticulum (ER) stress in liver-derived cultured cells. Excess copper also induced impairment of autophagic flux at the step of autophagosome-lysosome fusion, as well as Mallory-Denk body (MDB)-like inclusion body formation. Zinc ameliorated excess copper-induced impairment of autophagic flux and MDB-like inclusion body formation via the maintenance of ER homeostasis. Furthermore, zinc also ameliorated free fatty acid-induced impairment of autophagic flux. These results indicate that zinc may be able to protect hepatocytes from various ER stress-related conditions.

Lipid-Induced Endoplasmic Reticulum Stress Impairs Selective Autophagy at the Step of Autophagosome-Lysosome Fusion in Hepatocytes.

Blockage of hepatic autophagic degradation system occurs in obesity and is associated with the development of nonalcoholic fatty liver disease. However, the mechanism of this blockage remains unclear. We found a high-fat diet induced accumulation of autophagosomes in the mice livers. However, autophagy substrates such as p62 and ubiquitinated proteins also accumulated in the livers in this model. These findings indicate the possibility that a high-fat diet impairs autophagic flux in the liver. Then, to assess the autophagic flux in more detail, we performed analyses of autophagic flux in cultured hepatocytes exposed to monounsaturated fatty acids (FAs) or saturated FAs (SFAs). SFAs but not monounsaturated FAs suppressed degradation of contents in the autophagosomes. We analyzed each stage of the autophagy pathway (ie, autophagosome formation, autophagosome-lysosome fusion, lysosomal degradation) in cultured hepatocytes treated with monounsaturated FAs or SFAs and found that SFAs impaired autophagosome-lysosome fusion. This impairment occurred in an endoplasmic reticulum stress-dependent manner. Moreover, ubiquitin and p62-positive inclusions observed in high-fat diet-fed mice livers and SFA-treated cells were sequestered within autophagosomes. We also found that SFA-induced accumulation of Ser351-phosphorylated p62, which is indispensable for selective autophagy, further increased on administration of a lysosomal proteinase inhibitor. Although lipid-induced endoplasmic reticulum stress interferes with the autophagosome-lysosome fusion, selective autophagic sequestration of aggregated proteins is not inhibited.

Copper induces hepatocyte injury due to the endoplasmic reticulum stress in cultured cells and patients with Wilson disease.

Copper is an essential trace element, however, excess copper is harmful to human health. Excess copper-derived oxidants contribute to the progression of Wilson disease, and oxidative stress induces accumulation of abnormal proteins. It is known that the endoplasmic reticulum (ER) plays an important role in proper protein folding, and that accumulation of misfolded proteins disturbs ER homeostasis resulting in ER stress. However, copper-induced ER homeostasis disturbance has not been fully clarified. We treated human hepatoma cell line (Huh7) and immortalized-human hepatocyte cell line (OUMS29) with copper and chemical chaperones, including 4-phenylbutyrate and ursodeoxycholic acid. We examined copper-induced oxidative stress, ER stress and apoptosis by immunofluorescence microscopy and immunoblot analyses. Furthermore, we examined the effects of copper on carcinogenesis. Excess copper induced not only oxidative stress but also ER stress. Furthermore, excess copper induced DNA damage and reduced cell proliferation. Chemical chaperones reduced this copper-induced hepatotoxicity. Excess copper induced hepatotoxicity via ER stress. We also confirmed the abnormality of ultra-structure of the ER of hepatocytes in patients with Wilson disease. These findings show that ER stress plays a pivotal role in Wilson disease, and suggests that chemical chaperones may have beneficial effects in the treatment of Wilson disease.

Recognition of infection, status of outpatient treatment, and treatment history before carcinogenesis in patients with viral hepatitis-associated liver cancer.

We conducted a survey on the recognition of infection, status of outpatient treatment, and treatment history in hepatitis virus-associated hepatocellular carcinoma patients admitted to our department between 2005 and 2014. We compared these parameters in 75 patients with primary hepatitis B virus-associated hepatocellular carcinoma (HBV-HCC) and 307 patients with hepatitis C virus-associated hepatocellular carcinoma (HCV-HCC). Based on the presence or absence of outpatient treatment in medical institutions at the time of HCC diagnosis, the patients were divided into an outpatient treatment-free group or an outpatient treated group. In addition, the latter group was divided into three subgroups depending on the department consulted:the Department of Internal Medicine group, the Department of Gastroenterology group, and a hepatologist-treated group. Patients in the outpatient treatment-free group accounted for 40.0% of patients with HBV-HCC. In the outpatient treated group (60.0%), 21.3% were treated in the Department of Internal Medicine, 22.7% in the Department of Gastroenterology, and 16.0% were treated by a hepatologist. The percentage of HBV-HCC patients in the outpatient treatment-free group was 1.9 times higher than that in the HCV-HCC group and 0.6-fold higher in the hepatologist-treated group. Of the HBV-HCC patients, non-recognizers who were not diagnosed with a viral infection accounted for 21.3%, and non-outpatients who had not consulted a hospital despite the recognition of infection accounted for 33.3%. These percentages were approximately 2 times higher than in HCV-HCC patients. Of the HBV-HCC patients, 66.7% in the hepatologist-treated group had received nucleic acid analogue preparations. On the other hand, one patient in each of the Department of Internal Medicine and Department of Gastroenterology groups (approximately 6.0%) had received a nucleic acid analogue, lamivudine, despite the appearance of a resistant strain. In the HBV-HCC patients, the proportions of "non-recognizers" and "non-outpatients" were higher than in the HCV-HCC patients, suggesting a lack of appropriate treatment.

Alleviation mechanisms against hepatocyte oxidative stress in patients with chronic hepatic disorders.

AIM: Autophagy induction and Mallory-Denk body (MDB) formation have been considered to have cytoprotective effects from cellular stress in liver diseases. We investigated the relations among oxidative stress, autophagy and MDB formation in patients with chronic hepatitis B (CHB), chronic hepatitis C (CHC) and non-alcoholic fatty liver disease (NAFLD) to clarify the alleviation mechanisms against oxidative stress of hepatocytes. METHODS: First, we treated cultured cells with proteasome inhibitor (PI) or free fatty acid (FFA) and evaluated endoplasmic reticulum (ER) stress, oxidative stress, ubiquitinated proteins and p62 by western blotting. Then, we used human liver biopsy samples to evaluate oxidative stress, autophagy and MDB formation by immunohistochemical analysis. RESULTS: Treatment with PI or FFA increased ER stress, oxidative stress, ubiquitinated proteins and p62 in cultured cells. Human liver biopsy samples of CHC and NAFLD showed that MDB formed in areas with strong oxidative stress and that the MDB-containing cells circumvented oxidative stress. Keratin 8 (K8) expression was strong in MDB-containing cells in CHC and NAFLD. However, in CHB samples, the expression of K8 was not increased in response to oxidative stress and MDB aggregates did not appear. Aminotransferase values were significantly lower in patients with CHC and NAFLD in whom light chain 3 antibody expression was increased in response to oxidative stress. CONCLUSION: Strong expression of K8 was considered to be important for MDB formation. MDB protect liver cells from oxidative stress at a cellular level and autophagy reduced hepatic damage when it was induced in the hepatocytes exposed to strong oxidative stress.

A case of adrenal metastasis of hepatocellular carcinoma diagnosed by endoscopic ultrasound-guided fine-needle aspiration.

An 82-year-old man had been treated for lung adenocarcinoma and hepatocellular carcinoma (HCC). Contrast-enhanced computed tomography examination showed swelling of the left adrenal gland, suggesting metastasis of lung adenocarcinoma, HCC, or primary adrenal tumor. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) was performed for the pathological diagnosis, and adrenal metastasis of HCC was diagnosed. No notable complications due to EUS-FNA were found. There have been reports of adrenal metastasis due to various cancers, but there are few reports that can confirm the diagnosis of adrenal metastasis of HCC using EUS-FNA. Adrenal metastasis of HCC is not a rare condition, but it may be difficult to diagnose in the case of multiple cancer complications. We experienced a case in which EUS-FNA was useful for the diagnosis of adrenal metastasis of HCC.

Symptomatic Liver Cyst Successfully Treated with Transgastric Drainage and Sclerotherapy Using Minocycline Hydrochloride.

A liver cyst is hepatic fluid-filled cavities often detected in clinical surveillances such as a health examination. Although the liver cyst is usually asymptomatic and observed without any therapeutic intervention, it can be symptomatic and needs treatment due to its enlargement, hemorrhage, and infection. A 74-year-old woman presented with upper abdominal pain and a huge liver cyst in the left lobe. Several examinations including image findings revealed that the symptom could be derived from the liver cyst. Although there is no definite guideline of treatment for symptomatic liver cysts, percutaneous ultrasound-guided drainage with sclerotherapy or surgery is often selected. Because of anatomical accessibility to the liver cyst and the patient's wish, we performed endoscopic transgastric drainage with insertion of both an internal stent and an external nasocystic tube. Sclerotherapy with minocycline hydrochloride was performed through the nasocystic tube, and the liver cyst shrunk completely without any complications. This is the first reported method of administering minocycline hydrochloride through a nasocystic tube, which can be a therapeutic option for patients with symptomatic liver cysts.

An Unusual Abscess Associated with Gallbladder Perforation Successfully Treated with Percutaneous Transhepatic Gallbladder Drainage and Endoscopic Ultrasound-guided Abscess Drainage.

Abscesses associated with gallbladder perforation are often confined to the peri-gallbladder region. We herein report a rare case of gallbladder perforation in which the abscess cavity extended into the left upper quadrant. A 79-year-old woman developed gallbladder perforation secondary to acalculous cholecystitis. Computed tomography revealed fluid collection extending from the peri-gallbladder to the dorsal left hepatic lobe in contact with the stomach. We successfully treated percutaneous transhepatic gallbladder drainage and simultaneous endoscopic ultrasound-guided transgastric internal and external abscess drainage. This minimally invasive approach is considered safe and feasible for managing such a rare case.

IgG4-related hepatic inflammatory pseudotumor in a patient with serum IgG4-negative type 1 autoimmune pancreatitis.

IgG4-related disease (IgG4-RD) can cause heterogeneous lesion in various organs. Serum IgG4 levels are useful in monitoring patients with IgG4-RD; however, when it is negative, more careful observation is required. A 58-year-old woman who had been diagnosed with serum IgG4-negative type 1 autoimmune pancreatitis (AIP) 3 years prior visited our hospital for the evaluation of a liver tumor. She had visited a nearby hospital 1 month prior with complaints of a swelling in her right neck, and histological examinations were suggestive of IgG4-related sialadenitis. A positron emission tomography scan showed fluoro-deoxy-glucose accumulation in her right liver lobe; therefore, she was referred to our hospital. Liver tumor biopsy showed inflammatory cell infiltration and storiform fibrosis, without histological findings indicative of a malignancy. Many IgG4-positive cells were detected in immunostaining; thus, an IgG4-related hepatic inflammatory pseudo-tumor was diagnosed. After increasing in steroid dosage, the patient remained recurrence-free with 2 years. To our knowledge, this is the first report of mass-forming IPT for serum IgG4-negative type 1 AIP. Occasionally, IgG4-related IPT may appear in the periphery of the liver, and serum IgG4-negative cases should be more carefully observed because serum IgG4 is not an indicator.