Exploring the genetic diversity of the Japanese population: Insights from a large-scale whole genome sequencing analysis.

The Japanese archipelago is a terminal location for human migration, and the contemporary Japanese people represent a unique population whose genomic diversity has been shaped by multiple migrations from Eurasia. We analyzed the genomic characteristics that define the genetic makeup of the modern Japanese population from a population genetics perspective from the genomic data of 9,287 samples obtained by high-coverage whole-genome sequencing (WGS) by the National Center Biobank Network. The dataset comprised populations from the Ryukyu Islands and other parts of the Japanese archipelago (Hondo). The Hondo population underwent two episodes of population decline during the Jomon period, corresponding to the Late Neolithic, and the Edo period, corresponding to the Early Modern era, while the Ryukyu population experienced a population decline during the shell midden period of the Late Neolithic in this region. Haplotype analysis suggested increased allele frequencies for genes related to alcohol and fatty acid metabolism, which were reported as loci that had experienced positive natural selection. Two genes related to alcohol metabolism were found to be 12,500 years out of phase with the time when they began to increase in the allele frequency; this finding indicates that the genomic diversity of Japanese people has been shaped by events closely related to agriculture and food production.

Safety and feasibility of liver resection including major hepatectomy for geriatric patients with hepatocellular carcinoma: a retrospective observational study.

BACKGROUND: It is unclear whether hepatectomy, which ranges in invasiveness from partial to major hepatectomy, is safe and feasible for older adult patients. Therefore, we compared its postoperative complications and long-term outcomes between younger and older adult patients. METHODS: Patients who underwent hepatectomies for hepatocellular carcinoma (N = 883) were evaluated. Patients were divided into two groups: aged < 75 years (N = 593) and ≥ 75 years (N = 290). Short-term outcomes and prognoses were compared between the groups in the entire cohort. The same analyses were performed for the major hepatectomy cohort. RESULTS: In the entire cohort, no significant differences were found in complications between patients aged < 75 and ≥ 75 years, and the multivariate analysis did not reveal age as a prognostic factor for postoperative complications. However, overall survival was significantly worse in older patients, although no significant differences were noted in time to recurrence or cancer-specific survival. In the multivariate analyses of time to recurrence, overall survival, and cancer-specific survival, although older age was an independent poor prognostic factor for overall survival, it was not a prognostic factor for time to recurrence and cancer-specific survival. In the major hepatectomy subgroup, short- and long-term outcomes, including time to recurrence, overall survival, and cancer-specific survival, did not differ significantly between the age groups. In the multivariate analysis, age was not a significant prognostic factor for complications, time to recurrence, overall survival, or cancer-specific survival. CONCLUSION: Hepatectomy, including minor and major hepatectomy, may be safe and oncologically feasible options for selected older adult patients with hepatocellular carcinoma.

Challenges of secondary finding disclosure in genomic medicine in rare diseases: A nation-wide survey of Japanese facilities outsourcing comprehensive genetic testing.

Comprehensive genome analysis may reveal secondary findings (SFs) including pathogenic variants of genes other than those originally targeted. Comprehensive genetic analysis of rare diseases is generally performed as research in Japan. Therefore, the status and difficulties in SF disclosure remain unclear. To obtain information for the appropriate disclosure of SFs in rare diseases, we conducted a survey on how SFs are handled in clinical practice by facilities that outsource comprehensive genetic testing to other facilities. The response rate was 66.7% (40/60). Among the responding facilities, 55% had a policy of disclosing SFs with clinical utility and considered targeting actionable SFs with high penetrance. These facilities had difficulties in determining the disclosure targets (51%) and in genetic counseling (38%). Improving genetic literacy, establishment of surveillance systems, and providing insurance coverage for medical care to unaffected carriers were commonly cited as solutions to these difficulties. A comparison of the willingness to disclose SFs between overseas and in Japan showed more reluctance in Japan (86% vs. 65% for actionable SFs and 62% vs. 16% for non-actionable SFs). The group with difficulty in determining disclosure targets was significantly more likely to discuss this at conferences with other facilities and to refer guidelines. This suggests that the group with difficulties was unable to make decisions solely at their own facility and sought collaboration with other facilities. These findings suggest the necessity for a system that allows consultation with experts across facilities and guidelines that set forth policies for determining SFs.

Chemical reversal of abnormalities in cells carrying mitochondrial DNA mutations.

Mitochondrial DNA (mtDNA) mutations are the major cause of mitochondrial diseases. Cells harboring disease-related mtDNA mutations exhibit various phenotypic abnormalities, such as reduced respiration and elevated lactic acid production. Induced pluripotent stem cell (iPSC) lines derived from patients with mitochondrial disease, with high proportions of mutated mtDNA, exhibit defects in maturation into neurons or cardiomyocytes. In this study, we have discovered a small-molecule compound, which we name tryptolinamide (TLAM), that activates mitochondrial respiration in cybrids generated from patient-derived mitochondria and fibroblasts from patient-derived iPSCs. We found that TLAM inhibits phosphofructokinase-1 (PFK1), which in turn activates AMPK-mediated fatty-acid oxidation to promote oxidative phosphorylation, and redirects carbon flow from glycolysis toward the pentose phosphate pathway to reinforce anti-oxidative potential. Finally, we found that TLAM rescued the defect in neuronal differentiation of iPSCs carrying a high ratio of mutant mtDNA, suggesting that PFK1 represents a potential therapeutic target for mitochondrial diseases.

LOX-1 mediates inflammatory activation of microglial cells through the p38-MAPK/NF-κB pathways under hypoxic-ischemic conditions.

BACKGROUND: Microglial cells play an important role in the immune system in the brain. Activated microglial cells are not only injurious but also neuroprotective. We confirmed marked lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) expression in microglial cells in pathological lesions in the neonatal hypoxic-ischemic encephalopathy (nHIE) model brain. LOX-1 is known to be an activator of cytokines and chemokines through intracellular pathways. Here, we investigated a novel role of LOX-1 and the molecular mechanism of LOX-1 gene transcription microglial cells under hypoxic and ischemic conditions. METHODS: We isolated primary rat microglial cells from 3-day-old rat brains and confirmed that the isolated cells showed more than 98% Iba-1 positivity with immunocytochemistry. We treated primary rat microglial cells with oxygen glucose deprivation (OGD) as an in vitro model of nHIE. Then, we evaluated the expression levels of LOX-1, cytokines and chemokines in cells treated with or without siRNA and inhibitors compared with those of cells that did not receive OGD-treatment. To confirm transcription factor binding to the OLR-1 gene promoter under the OGD conditions, we performed a luciferase reporter assay and chromatin immunoprecipitation assay. In addition, we analyzed reactive oxygen species and cell viability. RESULTS: We found that defects in oxygen and nutrition induced LOX-1 expression and led to the production of inflammatory mediators, such as the cytokines IL-1ß, IL-6 and TNF-α; the chemokines CCL2, CCL5 and CCL3; and reactive oxygen/nitrogen species. Then, the LOX-1 signal transduction pathway was blocked by inhibitors, LOX-1 siRNA, the p38-MAPK inhibitor SB203580 and the NF-κB inhibitor BAY11-7082 suppressed the production of inflammatory mediators. We found that NF-κB and HIF-1α bind to the promoter region of the OLR-1 gene. Based on the results of the luciferase reporter assay, NF-κB has strong transcriptional activity. Moreover, we demonstrated that LOX-1 in microglial cells was autonomously overexpressed by positive feedback of the intracellular LOX-1 pathway. CONCLUSION: The hypoxic/ischemic conditions of microglial cells induced LOX-1 expression and activated the immune system. LOX-1 and its related molecules or chemicals may be major therapeutic candidates. Video abstract.

Estimation of the Number of Patients With Mitochondrial Diseases: A Descriptive Study Using a Nationwide Database in Japan.

BACKGROUND: To provide a better healthcare system for patients with mitochondrial diseases, it is important to understand the basic epidemiology of these conditions, including the number of patients affected. However, little information about them has appeared in Japan to date. METHODS: To gather data of patients with mitochondrial diseases, we estimated the number of patients with mitochondrial diseases from April 2018 through March 2019 using a national Japanese health care claims database, the National Database (NDB). Further, we calculated the prevalence of patients, and sex ratio, age class, and geographical distribution. RESULTS: From April 2018 through March 2019, the number of patients with mitochondrial diseases was 3,629, and the prevalence was 2.9 (95% confidence interval [CI], 2.8-3.0) per 100,000 general population. The ratio of females and males was 53 to 47, and the most frequent age class was 40-49 years old. Tokyo had the greatest number of patients with mitochondrial diseases, at 477, whereas Yamanashi had the fewest, at 13. Kagoshima had the highest prevalence of patients with mitochondrial diseases, 8.4 (95% CI, 7.1-10.0) per 100,000 population, whereas Yamanashi had the lowest, 1.6 (95% CI, 0.8-2.7). CONCLUSION: The number of patients with mitochondrial diseases estimated by this study, 3,269, was more than double that indicated by the Japanese government. This result may imply that about half of all patients are overlooked for reasons such as low severity of illness, suggesting that the Japanese healthcare system needs to provide additional support for these patients.

Homogeneity tests for one-way models with dependent errors under correlated groups.

We consider the problem of testing for the existence of fixed effects and random effects in one-way models, where the groups are correlated and the disturbances are dependent. The classical F-statistic in the analysis of variance is not asymptotically distribution-free in this setting. To overcome this problem, we propose a new test statistic for this problem without any distributional assumptions, so that the test statistic is asymptotically distribution-free. The proposed test statistic takes the form of a natural extension of the classical F-statistic in the sense of distribution-freeness. The new tests are shown to be asymptotically size α and consistent. The nontrivial power under local alternatives is also elucidated. The theoretical results are justified by numerical simulations for the model with disturbances from linear time series with innovations of symmetric random variables, heavy-tailed variables, and skewed variables, and furthermore from GARCH models. The proposed test is applied to log-returns for stock prices and uncovers random effects in sectors. Supplementary Information: The online version contains supplementary material available at 10.1007/s11749-022-00828-9.

[A Case of the Spontaneously Ruptured Recurrence Hepatic Angiosarcoma after Hepatic Resection].

A 67-year-old male was referred to our hospital in a state of shock. Transcatheter arterial embolization(TAE)was performed for the diagnosis of liver tumor rupture, followed by extended posterior area resection 18 days later. Histopathologically, he was diagnosed with hepatic angiosarcoma. The patient was discharged 18 days after the surgery, but readmitted on the 51st day due to bleeding shock caused by the rupture of a recurrent tumor in the liver. Although TAE was performed, the patient developed hepatic failure and died on postoperative day 81. Autopsy revealed multiple intrahepatic recurrence and peritoneal dissemination. Herein, we report a case of ruptured hepatic angiosarcoma that underwent hepatic resection after TAE and had a rapid outcome due to early postoperative rupture of recurrent lesion.

[Minimally Invasive Conversion Hepatectomy for Advanced Hepatocellular Carcinoma].

Some cases of advanced hepatocellular carcinoma(HCC)diagnosed as unresectable(UR)have been reported to undergo conversion surgery following systemic therapy. Furthermore, the combination of atezolizumab plus bevacizumab(Atez/Bev) shows potential therapeutic effects in conversion surgery for UR-HCC. At our hospital, neoadjuvant chemotherapy(NAC) using New-FP therapy(hepatic arterial infusion chemotherapy: HAIC)has been performed for borderline resectable HCC. New-FP therapy for advanced HCC with macrovascular invasion has a high response rate of 70%. For hepatectomy after NAC, a high response rate is required as a pretreatment, and New-FP therapy may be useful as the initial treatment. Limited reports exist of the laparoscopic approach in conversion surgery for advanced HCC. However, 14 cases of minimally invasive liver resection, including 10 cases after New-FP therapy and 4 cases after Atez/Bev therapy, have been safely performed conversion surgery for advanced HCC. In selected patients with advanced HCC, minimally invasive liver resection may be safely performed if the tumor shows shrinkage with various treatments.

Simultaneous measurement of the size and methylation of chromosome 4qA-D4Z4 repeats in facioscapulohumeral muscular dystrophy by long-read sequencing.

BACKGROUND: Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant muscular disorder characterized by asymmetric muscle wasting and weakness. FSHD can be subdivided into two types: FSHD1, caused by contraction of the D4Z4 repeat on chromosome 4q35, and FSHD2, caused by mild contraction of the D4Z4 repeat plus aberrant hypomethylation mediated by genetic variants in SMCHD1, DNMT3B, or LRIF1. Genetic diagnosis of FSHD is challenging because of the complex procedures required. METHODS: We applied Nanopore CRISPR/Cas9-targeted resequencing for the diagnosis of FSHD by simultaneous detection of D4Z4 repeat length and methylation status at nucleotide level in genetically-confirmed and suspected patients. RESULTS: We found significant hypomethylation of contracted 4q-D4Z4 repeats in FSHD1, and both 4q- and 10q-D4Z4 repeats in FSHD2. We also found that the hypomethylation in the contracted D4Z4 in FSHD1 is moderately correlated with patient phenotypes. CONCLUSIONS: Our method contributes to the development for the diagnosis of FSHD using Nanopore long-read sequencing. This finding might give insight into the mechanisms by which repeat contraction causes disease pathogenesis.

Lectin-Like Oxidized Low-Density Lipoprotein Receptor-1-Related Microglial Activation in Neonatal Hypoxic-Ischemic Encephalopathy: Morphologic Consideration.

Neonatal hypoxic-ischemic encephalopathy (nHIE) is a major neonatal brain injury. Despite therapeutic hypothermia, mortality and sequelae remain severe. The lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is associated with the pathophysiology of nHIE. In this study, morphologic change and microglial activation under the nHIE condition and LOX-1 treatment were investigated. The microglial activity and proliferation were assessed with a novel morphologic method, immunostaining, and quantitative PCR in the rat brains of both nHIE model and anti-LOX-1 treatment. Circumference ratio, the long diameter ratio, the cell area ratio, and the roundness of microglia were calculated. The correlation of the morphologic metrics and microglial activation in nHIE model and anti-LOX-1 treated brains was evaluated. LOX-1 was expressed in activated ameboid and round microglia in the nHIE model rat brain. In the evaluation of microglial activation, the novel morphologic metrics correlated with all scales of the nHIE-damaged and treated brains. While the circumference and long diameter ratios had a positive correlation, the cell area ratio and roundness had a negative correlation. Anti-LOX-1 treatment attenuated morphologic microglial activation and proliferation, and suppressed the subsequent production of inflammatory mediators by microglia. In human nHIE, round microglia and endothelial cells expressed LOX-1. The results indicate that LOX-1 regulates microglial activation in nHIE and anti-LOX-1 treatment attenuates brain injury by suppressing microglial activation.

Biallelic variants in LIG3 cause a novel mitochondrial neurogastrointestinal encephalomyopathy.

Abnormal gut motility is a feature of several mitochondrial encephalomyopathies, and mutations in genes such as TYMP and POLG, have been linked to these rare diseases. The human genome encodes three DNA ligases, of which only one, ligase III (LIG3), has a mitochondrial splice variant and is crucial for mitochondrial health. We investigated the effect of reduced LIG3 activity and resulting mitochondrial dysfunction in seven patients from three independent families, who showed the common occurrence of gut dysmotility and neurological manifestations reminiscent of mitochondrial neurogastrointestinal encephalomyopathy. DNA from these patients was subjected to whole exome sequencing. In all patients, compound heterozygous variants in a new disease gene, LIG3, were identified. All variants were predicted to have a damaging effect on the protein. The LIG3 gene encodes the only mitochondrial DNA (mtDNA) ligase and therefore plays a pivotal role in mtDNA repair and replication. In vitro assays in patient-derived cells showed a decrease in LIG3 protein levels and ligase activity. We demonstrated that the LIG3 gene defects affect mtDNA maintenance, leading to mtDNA depletion without the accumulation of multiple deletions as observed in other mitochondrial disorders. This mitochondrial dysfunction is likely to cause the phenotypes observed in these patients. The most prominent and consistent clinical signs were severe gut dysmotility and neurological abnormalities, including leukoencephalopathy, epilepsy, migraine, stroke-like episodes, and neurogenic bladder. A decrease in the number of myenteric neurons, and increased fibrosis and elastin levels were the most prominent changes in the gut. Cytochrome c oxidase (COX) deficient fibres in skeletal muscle were also observed. Disruption of lig3 in zebrafish reproduced the brain alterations and impaired gut transit in vivo. In conclusion, we identified variants in the LIG3 gene that result in a mitochondrial disease characterized by predominant gut dysmotility, encephalopathy, and neuromuscular abnormalities.

5-HT1A Receptor Agonist Treatment Partially Ameliorates Rett Syndrome Phenotypes in mecp2-Null Mice by Rescuing Impairment of Neuron Transmission and the CREB/BDNF Signaling Pathway.

Rett syndrome (RTT) is an X-linked neurodevelopmental disorder caused by mutations in the gene that encodes methyl CpG-binding protein 2 (MECP2) and is characterized by the loss of acquired motor and language skills, stereotypic movements, respiratory abnormalities and autistic features. There has been no effective treatment for this disorder until now. In this study, we used a Mecp2-null (KO) mouse model of RTT to investigate whether repeated intraperitoneal treatment with the 5-HT1A receptor agonist tandospirone could improve the RTT phenotype. The results showed that administration of tandospirone significantly extended the lifespan of Mecp2-KO mice and obviously ameliorated RTT phenotypes, including general condition, hindlimb clasping, gait, tremor and breathing in Mecp2-KO mice. Tandospirone treatment significantly improved the impairment in GABAergic, glutaminergic, dopaminergic and serotoninergic neurotransmission in the brainstem of Mecp2-KO mice. Decreased dopaminergic neurotransmission in the cerebellum of Mecp2-KO mice was also significantly increased by tandospirone treatment. Moreover, RNA-sequencing analysis found that tandospirone modulates the RTT phenotype, partially through the CREB1/BDNF signaling pathway in Mecp2-KO mice. These findings provide a new option for clinical treatment.

[A Case of Small Cell Neuroendocrine Carcinoma of the Gallbladder].

A 76-year-old female was referred to our hospital with a tumor of the gallbladder using ultrasonography. CT and MRI of the abdomen and endoscopic ultrasonography revealed thickened walls of the body of her gallbladder. Endoscopic retrograde cholangiopancreatography was performed, adenocarcinoma was suspected based on bile cytology, and extended cholecystectomy with lymphadenectomy was performed. The postoperative pathological diagnosis was small cell neuroendcrine carcinoma. Three months after the surgery, CT revealed that she had multiple recurrences in the distant lymph node, and she died two months later. Gallbladder neuroendocrine carcinoma is rare and which is thought to have a poor prognosis, so effective multidisciplinary treatment must be required for this disease. In this case, it might need not to hesitate to perform preoperative endoscopic ultrasound guided fine needle aspiration(EUS-FNA).

DNA analysis of benign adult familial myoclonic epilepsy reveals associations between the pathogenic TTTCA repeat insertion in SAMD12 and the nonpathogenic TTTTA repeat expansion in TNRC6A.

Benign adult familial myoclonic epilepsy (BAFME) is an autosomal dominant disease characterized by adult-onset tremulous hand movement, myoclonus, and infrequent epileptic seizures. Recently, intronic expansion of unstable TTTCA/TTTTA pentanucleotide repeats in SAMD12, TNRC6A, or RAPGEF2 was identified as pathological mutations in Japanese BAFME pedigrees. To confirm these mutations, we performed a genetic analysis on 12 Japanese BAFME pedigrees. A total of 143 participants, including 43 familial patients, 5 suspected patients, 3 sporadic nonfamilial patients, 22 unaffected familial members, and 70 unrelated controls, were screened for expanded abnormal pentanucleotide repeats in SAMD12, TNRC6A, RAPGEF2, YEAT2, MARCH6, and STARD7. DNA samples were analyzed using Southern blotting, long-range polymerase chain reaction (PCR), repeat-primed PCR, and long-range PCR followed by Southern blotting. Of the 51 individuals with clinically diagnosed or suspected BAFME, 49 carried a SAMD12 allele with an expanded TTTCA/TTTTA pentanucleotide repeat. Genetic and clinical anticipation was observed. As in previous reports, the one patient with homozygous mutant alleles showed more severe symptoms than the heterozygous carriers. In addition, screening for expanded pentanucleotide repeats in TNRC6A revealed that the frequency of expanded TTTTA repeat alleles in the BAFME group was significantly higher than in the control group. All patients who were clinically diagnosed with BAFME, including those in the original family reported by Yasuda, carried abnormally expanded TTTCA/TTTTA repeat alleles of SAMD12. Patients with BAFME also frequently carried a TTTTA repeat expansion in TNRC6A, suggesting that there may be unknown factors in the ancestry of patients with BAFME that make pentanucleotide repeats unstable.

Higd1a improves respiratory function in the models of mitochondrial disorder.

The respiratory chain (RC) transports electrons to form a proton motive force that is required for ATP synthesis in the mitochondria. RC disorders cause mitochondrial diseases that have few effective treatments; therefore, novel therapeutic strategies are critically needed. We previously identified Higd1a as a positive regulator of cytochrome c oxidase (CcO) in the RC. Here, we test that Higd1a has a beneficial effect by increasing CcO activity in the models of mitochondrial dysfunction. We first demonstrated the tissue-protective effects of Higd1a via in situ measurement of mitochondrial ATP concentrations ([ATP]mito) in a zebrafish hypoxia model. Heart-specific Higd1a overexpression mitigated the decline in [ATP]mito under hypoxia and preserved cardiac function in zebrafish. Based on the in vivo results, we examined the effects of exogenous HIGD1A on three cellular models of mitochondrial disease; notably, HIGD1A improved respiratory function that was coupled with increased ATP synthesis and demonstrated cellular protection in all three models. Finally, enzyme kinetic analysis revealed that Higd1a significantly increased the maximal velocity of the reaction between CcO and cytochrome c without changing the affinity between them, indicating that Higd1a is a positive modulator of CcO. These results corroborate that Higd1a, or its mimic, provides therapeutic options for the treatment of mitochondrial diseases.

Whole genome sequencing of 45 Japanese patients with intellectual disability.

Intellectual disability (ID) is characterized by significant limitations in both intellectual functioning and adaptive behaviors, originating before the age of 18 years. However, the genetic etiologies of ID are still incompletely elucidated due to the wide range of clinical and genetic heterogeneity. Whole genome sequencing (WGS) has been applied as a single-step clinical diagnostic tool for ID because it detects genetic variations with a wide range of resolution from single nucleotide variants (SNVs) to structural variants (SVs). To explore the causative genes for ID, we employed WGS in 45 patients from 44 unrelated Japanese families and performed a stepwise screening approach focusing on the coding variants in the genes. Here, we report 12 pathogenic and likely pathogenic variants: seven heterozygous variants of ADNP, SATB2, ANKRD11, PTEN, TCF4, SPAST, and KCNA2, three hemizygous variants of SMS, SLC6A8, and IQSEC2, and one homozygous variant in AGTPBP1. Of these, four were considered novel. Furthermore, a novel 76 kb deletion containing exons 1 and 2 in DYRK1A was identified. We confirmed the clinical and genetic heterogeneity and high frequency of de novo causative variants (8/12, 66.7%). This is the first report of WGS analysis in Japanese patients with ID. Our results would provide insight into the correlation between novel variants and expanded phenotypes of the disease.

Clinicopathological findings of a mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes/Leigh syndrome overlap patient with a novel m.3482A>G mutation in MT-ND1.

We report clinicopathological findings of a patient with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes/Leigh syndrome (MELAS/LS) associated with a novel m.3482A>G mutation in MT-ND1. A 41-year-old woman had experienced multiple stroke-like episodes since age 16. She developed akinetic mutism two months before admission to our hospital. Neurological examination revealed akinetic mutism, bilateral deafness, and muscular atrophy. Cerebrospinal fluid tests revealed elevated pyruvate and lactate levels. Fluid-attenuated inversion recovery images on magnetic resonance imaging showed hyperintense areas in the right frontal and both sides of temporal and occipital lobes, both sides of the striatum, and the midbrain. Muscle biopsy revealed strongly succinate dehydrogenase-reactive blood vessels. L-arginine therapy improved her consciousness and prevented further stroke-like episodes. However, she died from aspiration pneumonia. Postmortem autopsy revealed scattered infarct-like lesions with cavitation in the cerebral cortex and necrotic lesions in the striatum and midbrain. The patient was pathologically confirmed as having MELAS/LS based on two characteristic clinicopathological findings: presenting MELAS/LS overlap phenotype and effectiveness of L-arginine treatment.

Central hepatopancreatoduodenectomy-oncological effectiveness and parenchymal sparing option for diffusely spreading bile duct cancer: report of two cases.

BACKGROUND: Hepatopancreatoduodenectomy (HPD) for diffusely spreading bile duct cancer (DSBDC) usually involves a major hepatectomy and a concomitant pancreatoduodenectomy, and is still challenging surgery because of postoperative liver failure. The present case report demonstrated two cases of DSBDC where we could achieve successful HPD with central liver resection (CHPD) as liver parenchymal sparing surgery. CASE PRESENTATION: In Case 1, endoscopic retrograde cholangiography (ERC) with multiple biopsies revealed that she had DSBDC with Bismuth-Corlette type IIIA. 3D integrated images reconstructed by contrast enhanced CT and CT with drip infusion cholecystocholangiography data revealed the right antero-ventral bile duct (RAVD) confluent to the right hepatic duct and the right antero-dorsal bile duct (RADD) independently confluent to the right posterior bile duct (RPD). Tumor extended common bile duct including intrapancreatic bile duct to the left hepatic duct and RAVD, but the RADD and RPD were spared. Because the future liver remnant (FLR) was assumed not to achieve desirable volume by preoperative portal vein embolization for left or right trisegmentectomy, CHPD including resection of the segments IV and I, and the right antero-ventral segment was done and achieved R0. This procedure is tailored to the anatomical extent of disease in the context of variable biliary anatomy as a modified CHPD, and to our knowledge, this is the first reported case of modified CHPD with antero-dorsal segment preservation. In Case 2, preoperative imaging revealed DSBDC with Bismuth Corlette type IIIA. FLR volume was assumed insufficient for major hepatectomy, CHPD including resection of the segments IV and I, and the right anterior sector was done with R0. The remnant liver volumes of these cases were spared by 55.1% and 25% respectively, and postoperative course was uneventful in both. CONCLUSION: CHPD should be considered a valid option for well-selected cases of DSBDC. This is the first case report of modified CHPD with antero-dorsal segment preservation.

Laparoscopic left hepatectomy for a patient with intrahepatic cholangiocarcinoma metastasis in the falciform ligament: a case report.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is primary cancer of the liver with poor prognosis because of its high potential for recurrence and metastasis. We experienced a rare case of ICC with hematogenous metastasis to the falciform ligament. We aimed to clarify the route of metastasis to the mesentery by increasing the accuracy of preoperative imaging and establish a hepatectomy to control cancer. CASE PRESENTATION: An 85-year-old woman was referred to our hospital for a detailed study of progressively increasing liver tumors. She had no subjective symptoms. Her medical history showed hypertension, aneurysm clipping for cerebral hemorrhage, and gallstones. A detailed physical examination and laboratory data evaluation included tumor markers but did not demonstrate any abnormalities. On computed tomography scan, contrast-enhanced ultrasound, and magnetic resonance imaging with gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid, the tumor appeared to be located in liver segment IV, protruding outside the liver. It appeared to contain two distinct components; we suspected ICC in the intrahepatic tumor component. Laparoscopic observation revealed that the extrahepatic lesion was an intra-falciform ligament mass; laparoscopic left hepatectomy was performed. Microscopically, the main tumor in segment IV was 15 mm in diameter and was diagnosed as moderately and poorly differentiated ICC. The tumor of the intra-falciform ligament was not continuous with the main intrahepatic nodule and was also diagnosed as ICC with extensive necrosis. There were no infiltrates in the round ligament of the liver, and several tumor thrombi were found in the small veins of the falciform ligament. CONCLUSIONS: To date, there have been a few reports of metastases of primary liver cancer to the falciform ligament. At the time of preoperative imaging and pathological diagnosis, this case was suggestive of considering that the malignant liver tumor might be suspected of metastasizing to the falciform ligament. Our case improves awareness of this pathology, which can be useful in the future when encountered by hepatic specialists and surgeons.