Gastric tumor mimicking bronchial tissue associated with a laryngotracheoesophageal cleft: a case report.

BACKGROUND: Laryngotracheoesophageal cleft (LTEC) is a rare disease in which the larynx and trachea communicate posteriorly to the esophagus. It is often associated with other congenital malformations, particularly gastrointestinal anomalies. Herein, we report a case of LTEC associated with a gastric polypoid lesion in bronchial tissue. CASE PRESENTATION: A gastric mass was detected in a male fetus since week 21 of gestation using fetal ultrasonography. Esophagogastroduodenoscopy performed after birth revealed a pedunculated polypoid lesion of the gastric fornix. The patient experienced frequent vomiting and aspiration pneumonia, which persisted after nasoduodenal tube feeding. Communication between the airway and esophagus was suspected. Laryngoscopy performed 30 days later revealed an LTEC (type III). Partial gastrectomy was performed when the patient was 93 days of age. Histopathological examination revealed tumor consisting of cartilage tissue covered with a layer of respiratory epithelium. CONCLUSION: The gastric tumor associated with LTEC exhibited structures mimicking bronchial tissue. LTEC occurs because of foregut maldevelopment, and the tumorous respiratory tissue in the stomach may have been formed from the same abnormal foregut development event as LTEC.

Frequency and function of circulating regulatory T-cells in biliary atresia.

PURPOSE: Although the impairment of regulatory T-cells (Tregs) has been shown in the liver or portal area of biliary atresia (BA) the frequency and function of circulating Tregs in BA patients is poorly understood. We aimed to investigate the frequency and function of circulating Tregs in BA patients. METHODS: Peripheral blood mononuclear cells were collected from 25 BA patients and 24 controls. Treg frequency was measured by flow cytometry; function was determined by T-cell proliferation assay. We also assessed the association between Treg frequency/function and clinical parameters in BA cases. RESULTS: There was no significant difference between the two groups in both frequency (BA: 3.4%; control: 3.2%; p = 0.97) and function (BA: 22.0%; control: 7.5%; p = 0.23) of Tregs. We further focused on 13 preoperative BA patients and 14 age-matched controls. Neither Treg frequency nor function were significantly different (frequency: BA: 4.6%; control: 3.4%; p = 0.38, function: BA: 2.7%; control: 7.6%; p = 0.89). There was no association between Treg frequency/function and clinical parameters. CONCLUSION: Neither the frequency nor function of circulating Tregs was affected in BA patients, suggesting the negative role of circulating Tregs in the pathogenesis of BA. Further investigation of local Treg profiles is warranted.

Usefulness of hepatobiliary scintigraphy for predicting late complications in patients with choledochal cysts.

PURPOSE: Hepatobiliary scintigraphy is a minimally invasive imaging method that evaluates bile flow dynamics. At our hospital, it has been performed for postoperative evaluation of patients with choledochal cysts (CC). This study evaluated the usefulness of biliary scintigraphy for predicting late complications in patients with CCs. METHODS: The study included pediatric patients with CC who underwent surgery at Chiba University Hospital from 1978 to 2020, followed by postoperative biliary scintigraphy and subsequent radiologic evaluation. The patients were divided into two groups according to the presence or absence of "biliary cholestasis" on biliary scintigraphy. RESULTS: The study included 108 patients, with a median age at surgery of 2 years and 11 months. The median follow-up period was 5203 days, with 11 hepatolithiasis cases and 8 cholangitis cases. No patients had cholangiocarcinoma. Twelve patients were considered to have "cholestasis" following biliary scintigraphy evaluation. There was no significant difference in the occurrence of hepatolithiasis between the cholestasis and non-cholestasis groups (p = 0.47), but cholangitis was significantly more common in the cholestasis group (p = 0.016). CONCLUSION: Biliary cholestasis on postoperative hepatobiliary scintigraphy was a risk factor for cholangitis in patients with CCs. These particular patients should be monitored carefully.

Amylase Levels Are Useful for Diagnosing Omphalomesenteric Cysts: A Case Report.

Omphalomesenteric cysts are an exceedingly rare type of embryologic remnant of the omphalomesenteric duct. Owing to its rarity and unspecific imaging findings, it is occasionally difficult to diagnose preoperatively. Herein, we report the case of a 15-month-old female with an omphalomesenteric cyst that presented as a painful abdominal mass. Imaging showed a 4 cm cystic lesion just beneath the umbilicus, which also contained a 1 cm enhanced lesion. On the immediate right side of this cyst, a 7 cm hematoma was found within the abdominal wall. Aspiration revealed bloody fluid with an amylase level of 38,250 U/L. She was then diagnosed with an omphalomesenteric cyst, with aberrant pancreas and associated hematoma of the abdominal wall. These findings were confirmed with laparotomy and subsequent pathological examinations. The high level of amylase in the cyst led us to speculate the existence of ectopic pancreatic tissue. Thus, amylase measurement may be considered for the diagnosis of an omphalomesenteric cyst.

Combined Use of Three-Dimensional Construction and Indocyanine Green-Fluorescent Imaging for Resection of Multiple Lung Metastases in Hepatoblastoma.

It is essential to accurately and safely resect all tumors during surgery for multiple lung metastases. Here, we report a case of hepatoblastoma (HB) with multiple pulmonary nodules that ultimately underwent complete resection using combined three-dimensional image reconstruction and indocyanine green (ICG) fluorescence guidance. A 1-year-old boy was diagnosed with HB and multiple lung metastases. After intensive chemotherapy, complete resection with subsegmentectomy (S5 + 6) and partial resection (S3, S8) were performed. More than 100 pulmonary nodules, which remained visible on computed tomography (CT) despite additional postoperative chemotherapy, were subjected to pulmonary resection. We used the SYNAPSE VINCENT software (Fujifilm Medical, Tokyo, Japan) to obtain three-dimensional images of the nodules. We numbered each nodule, and 33 lesions of the right lung were resected by multiple wedge resections through a right thoracotomy, with the aid of palpation and ICG fluorescence guidance. One month after the right metastasectomy, resection of 64 lesions in the left lung was performed via left thoracotomy. Postoperative CT showed complete clearance of the lung lesions, and the patient remained disease-free for 15 months after the treatment. This case study confirms that the combination of three-dimensional localization and ICG fluorescence guidance allows for accurate and safe resection of nearly 100 lung metastases.

Wnt5a plays a critical role in anal opening in mice at an early stage of embryonic development.

PURPOSE: Anorectal malformations are associated with other organ malformations. Proximodistal elongation of the cloacal plate and anal opening at its distal end are essential for anal development. However, the anal developmental stage in which Wnt5a is directly involved remains unelucidated. Here, we attempted to identify this developmental stage; since Wnt5a is expressed in the mesoderm, and the striated muscle complex (SMC) in mice develops from the mesoderm, we also examined Wnt5a contribution to SMC development. METHODS: We established conditional knockout (CKO) mice in which Wnt5a could be knocked out using an appropriate tamoxifen dose. We evaluated the macroscopic appearance and histopathological features of Wnt5aCKO and wild-type mouse embryos. RESULTS: Wnt5aCKO mice showed phenotypes typical of Wnt5a constitutional knockout mice when Wnt5a was knocked out at E8-E11. Furthermore, the anus failed to open when Wnt5a was knocked out at E8 but opened when it was knocked out at E9 or thereafter. The caudal end of the SMC was dysplastic in Wnt5aCKO mice induced at E8, but was unaffected when mice were induced at E9 or thereafter. CONCLUSION: We suggest a critical role for Wnt5a in anal opening and SMC formation at a very early stage of embryonic development.

Larger Physique as a Risk Factor for Infantile Appendicitis: A Retrospective Study.

The clinical features and risk factors of acute appendicitis in infants are unclear. Our aim was to evaluate the association between anthropometrics and the occurrence of infantile appendicitis. This was a retrospective study of infants (<6 years of age) and school-age children (6-10 years of age) of Asian ethnicity who required hospitalization for appendicitis at our two participating institutions between 2004 and 2018. The Z-score for height, body weight, and body mass index (BMI) was compared between the two groups, as well as between patients presenting with perforated and non-perforated appendicitis. The analysis included data from 73 infants and 362 school-age children. Z-scores were greater in infants than in school-age children for height (0.37 versus -0.03, p = 0.003) and body weight (0.12 versus -0.36, p = 0.023), with no between-group difference for the Z-score of BMI. There was no difference in Z-scores for height, weight, and BMI between the perforated and non-perforated appendicitis infant groups. Infants presenting with acute appendicitis were characterized by a larger physique but with normal proportion. This trend was not observed in school-age children. Therefore, larger infants presenting with abdominal pain should be screened for appendicitis.

Genetic background-dependent abnormalities of the enteric nervous system and intestinal function in Kif26a-deficient mice.

The Kif26a protein-coding gene has been identified as a negative regulator of the GDNF-Ret signaling pathway in enteric neurons. The aim of this study was to investigate the influence of genetic background on the phenotype of Kif26a-deficient (KO, -/-) mice. KO mice with both C57BL/6 and BALB/c genetic backgrounds were established. Survival rates and megacolon development were compared between these two strains of KO mice. Functional bowel assessments and enteric neuron histopathology were performed in the deficient mice. KO mice with the BALB/c genetic background survived more than 400 days without evidence of megacolon, while all C57BL/6 KO mice developed megacolon and died within 30 days. Local enteric neuron hyperplasia in the colon and functional bowel abnormalities were observed in BALB/c KO mice. These results indicated that megacolon and enteric neuron hyperplasia in KO mice are influenced by the genetic background. BALB/c KO mice may represent a viable model for functional gastrointestinal diseases such as chronic constipation, facilitating studies on the underlying mechanisms and providing a foundation for the development of treatments.

Optimization of surgical timing of congenital diaphragmatic hernia using the quantified flow patterns of patent ductus arteriosus.

PURPOSE: The optimal timing of surgery for congenital diaphragmatic hernia (CDH) is controversial. We aimed to validate our protocol for the timing of CDH repair using the quantified patent ductus arteriosus (PDA) flow pattern. METHODS: This retrospective comparative study analyzed patients with a prenatal diagnosis of isolated CDH between 2007 and 2020. We defined the "LR ratio" as the percentage of velocity-time integral (VTI) of the left-to-right flow of PDA against overall VTI on echocardiography. Since 2010, we followed the decision criterion of performing surgery when LR ratio of > 50% has been achieved in the patients (protocol group). The protocol group (2010-2020) was compared with the historical control group (2007-2009). RESULTS: The average age at surgery was 104.1 ± 175.9 and 37.3 ± 30.6 h in the control and protocol groups, respectively (p = 0.11). Survival rate (88.9% vs. 95.0%, p = 0.53) and the rate of worsening of pulmonary hypertension within 24 h after surgery (22.2% vs. 10.0%, p = 0.57) were not different between the groups. The protocol group had a significantly shorter duration of tracheal intubation (26.9 ± 21.1 vs. 13.3 ± 9.5 days, p = 0.03). CONCLUSION: Our decision criterion might have the advantage of facilitating early and safe surgery for patients with CDH.

Acid and bolus exposure in pediatric reflux disease according to the presence and severity of esophageal mucosal lesions.

PURPOSE: The relationship between reflux index (RI) and bolus exposure parameters in multichannel intraluminal impedance (MII) has not been examined sufficiently among children. The significance of acid and bolus exposure in evaluating pediatric reflux disease (RD) was explored by focusing on mucosal lesions. METHODS: We conducted MII-pH on 28 patients (median age 8 years) with suspected RD. We assessed relationships between RI and bolus exposure indices, and also compared acid and bolus exposures across patients grouped by endoscopic esophageal mucosal lesions. RESULTS: RI correlated significantly with distal acid reflux events (r = 0.60), acid bolus exposure time (BET) (0.55), and bolus clearance time (BCT) (0.48). Significant differences were observed among the control, non-erosive RD (NERD), and erosive RD (ERD) groups in all acid and several bolus exposure indices (distal and proximal frequencies, and BCT), while no significant difference was apparent between NERD and ERD. Acid exposure tended to be more severe in high-grade than in low-grade ERD, while no similar tendency was found in any bolus parameters other than BCT. CONCLUSIONS: MII-pH showed great potential for investigating the pathophysiology of pediatric RD, with RI revealing different correlations with variable bolus exposure indices. However, no specific parameters allowing precise discrimination between RDs or mucosal severities were identified.

Soluble factors derived from neuroblastoma cell lines suppress dendritic cell differentiation and activation.

Dendritic cells (DC) play a key role in the initiation of both antitumor immunity and immunological tolerance. It has been demonstrated that exposure to soluble factors produced by tumor cells modulates DC functions and induces tolerogenic DC differentiation. In this study, we investigated the effects of neuroblastoma cell line-derived soluble factors on DC differentiation. Monocytes isolated from healthy volunteers were incubated with interleukin (IL)-4 and granulocyte-macrophage colony-stimulating factor in the presence of culture supernatants from neuroblastoma cell lines. The culture supernatants from neuroblastoma cell lines, such as NLF and GOTO, partially blocked both downregulation of CD14 and upregulation of CD1a, and dramatically decreased IL-12 and tumor necrosis factor (TNF)-α production from mature DC, while no effect of SH-SY5Y cell supernatant was noted. In addition, IL-6 and IL-10 production from monocytes was increased by the supernatants of NLF and GOTO cells at 24 hours after incubation. Furthermore, we evaluated DC functions through stimulation of invariant natural killer T (iNKT) cells. α-Galactosylceramide-pulsed DC co-cultured with supernatants of NLF cells were unable to sufficiently stimulate iNKT cells. The decreased ability of iNKT cells to produce interferon (IFN)-γ after stimulation with neuroblastoma cell line supernatant-cultured DC was reversed by addition of IL-12. CD40 expression and IL-12 production in NLF-sup-treated DC were increased by addition of exogenous IFN-γ. These results indicate that tolerogenic DC are induced in the neuroblastoma tumor microenvironment and attenuate the antitumor effects of iNKT cells. Interactions between iNKT cells and αGalCer-pulsed DC have the potential to restore the immunosuppression of tolerogenic DC through IFN-γ production.

Significance and indications for reoperative portoenterostomy in biliary atresia in light of long-term outcome.

BACKGROUND: Among biliary atresia (BA) patients undergoing revision following failed portoenterostomy, long-term native liver survival (NLS), physical condition, and indications for revision were explored. METHODS: From 1977-2015, 33 of 95 BA patients (35%) at our institution underwent revision. Ten- and 20-year NLS rates (NLSRs) and biochemical statuses of 20-year-old native liver survivors were compared between post-portoenterostomy BA patients with and without history of revision. Factors associated with 10-year NLS following revision and optimal cut-offs for potential predictors were analyzed. RESULTS: Overall 10- and 20-year NLSRs were 57% and 54%, respectively. Ten- and 20-year NLSRs were 49% and 45% in the revision group and 63% and 61% in the non-revision group, respectively. Among 20-year-old native liver survivors, differences in admission rates between ages 10-20 years were not significant for cholangitis (revision, 46%; non-revision, 40%; P = 0.30) or portal hypertension (revision, 38%; non-revision, 15%; P = 0.21). Differences in hepatobiliary function-associated blood tests between these groups at 20 years old were only significant for aspartate aminotransferase (P = 0.02) and gamma-glutamyl transpeptidase (P = 0.047). Among potential predictors of 10-year NLS that we investigated, rate of change in total bilirubin (TB) over the first month post-portoenterostomy was best (P = 0.0019), and the receiver operating characteristic curve revealed an optimal cut-off for this first-month change in TB of -3.7 mg/dl (area under the curve, 0.85; sensitivity, 0.79; specificity, 0.83). CONCLUSIONS: In approximately half of the patients, revision provided 10- and 20-year NLS, and biochemical status at 20 years old was comparable across revision and non-revision patients. Rate of change in TB during the first month post-portoenterostomy offers a sensitive predictor of revision.

Prediction of respiratory collapse among pediatric patients with mediastinal tumors during induction of general anesthesia.

PURPOSE: Fatality resulting from respiratory collapse (RC) during general anesthesia (GA) induction in children with mediastinal tumors has been reported. We explored potentially useful parameters for predicting the risk of RC based on objective imaging results. METHODS: We retrospectively reviewed the records of 31 patients (median age: 4years; range: 4months-15years) with mediastinal tumors treated between 2000 and 2015. Comparing those with RC under GA induction to those without (RC group vs. non-RC group), we analyzed a variety of factors that might predict respiratory obstruction during GA induction, including our new parameter, the standardized tumor volume (STV), which is adapted from the formula for the volume of an ellipsoid. RESULTS: All eight patients in the RC group had large tumors in the anterior mediastinum, including lymphoma, teratoma, and germ cell tumor. The mean STV value of the RC group was significantly larger than that of the non-RC group (3.6±1.4 vs. 1.4±1.0, p=0.006). Using an STV cut-off value of 2.5, the sensitivity and specificity for predicting RC under GA induction were both 0.86, making STV more useful than previously reported risk factors. CONCLUSION: Anterior mediastinal tumors in children can often cause airway obstruction under GA induction. Measuring STV can help predict the respiratory risk during GA among pediatric patients with anterior mediastinal tumors. LEVEL OF EVIDENCE: III.

Frequency and proliferative response of circulating invariant natural killer T cells in pediatric patients with malignant solid tumors.

BACKGROUND: Invariant natural killer T (iNKT) cells play an important role in tumor immunity, enhancing both innate and acquired immunity. We have previously shown the enhancement of antibody-dependent cellular cytotoxicity against neuroblastoma by activated iNKT cells. As a first step towards clinical application, we studied the frequency and proliferative response of circulating iNKT cells in children with and without cancer. METHODS: Blood samples were collected from 10 patients with pediatric malignant solid tumors and 11 patients with non-neoplastic diseases (control). The frequency of circulating iNKT cells was quantified by flow cytometry. Whole peripheral blood mononuclear cells were then stimulated with α-galactosylceramide (α-GalCer) for 7 days, and the expansion rate of the iNKT-cell fraction was assessed. RESULTS: The frequency of iNKT cells in the patients of the cancer and control group did not differ to a statistically significant extent. The iNKT-cell population increased after α-GalCer stimulation in all cases. The iNKT cells of patients who had undergone intensive chemotherapy also had the potential to expand in vitro. CONCLUSIONS: Unlike adult cancer patients, the numbers of circulating iNKT cells were not decreased in pediatric cancer patients. α-GalCer stimulation induced a proliferative response in all of the patients.

Invariant natural killer T infiltration in neuroblastoma with favorable outcome.

BACKGROUND: Tumor immunity has been suggested to play a key role in clinical and biological behavior of neuroblastomas. Given that CD1-restricted invariant natural killer T (iNKT) cells enhance both innate and acquired tumor immunity, we investigated the expression of the iNKT-cell-specific T-cell receptor Vα24-Jα18 in neuroblastoma tissues and its correlation with clinical and biological characteristics. METHODS: Using real- time quantitative PCR, we quantified the expression of Vα24-Jα18 in untreated tumor samples from 107 neuroblastoma cases followed in our institution and analyzed the correlation between the presence of infiltrated iNKT cells and clinical characteristics or patients' outcome. RESULTS: Vα24-Jα18 receptor was detected in 62 untreated cases (57.9%). The expression was significantly higher in stages 1, 2, 3, or 4S (P = 0.0099), in tumors with low or intermediate risk (P = 0.0050), with high TrkA expression (P = 0.0229), with favorable histology (P = 0.0026), with aneuploidy (P = 0.0348), and in younger patients (P = 0.0036). The overall survival rate was significantly higher in patients with iNKT-cell infiltration (log-rank; P = 0.0089). CONCLUSIONS: Since tumor-infiltrating iNKT cells were predominantly observed in neuroblastomas undergoing spontaneous differentiation and/or regression, we suggest that iNKT cells might play a key role in these processes.

Significance of imaging modalities for preoperative evaluation of the pancreaticobiliary system in surgery for pediatric choledochal cyst.

OBJECTIVE: Roles of magnetic resonance cholangiopancreatography (MRCP), endoscopic retrograde cholangiopancreatography (ERCP), drip infusion cholangiography with computed tomography (DIC-CT), and intraoperative cholangiopancreatography (IOCP) in visualizing pancreaticobiliary anatomy for pediatric choledocal cyst (CC) operations were examined. METHODS: From 1980-2013, 117 pediatric CC patients (median age, 3 years) underwent hepaticojejunostomy at our institution, with imaging modalities of ERCP (n = 81 over 34 years), MRCP, DIC-CT, and IOCP (n = 45, 20, and 45 cases over the last 12 years). First, visualization rates for pancreaticobiliary maljunction (PBM), common bile duct (CBD), pancreatic duct (PD), and intrahepatic bile duct (IHBD) were investigated. Sensitivity, specificity, and accuracy for detecting hepatic duct stricture were then compared between MRCP and IOCP. RESULT: Visualization rates of PBM, CBD, PD, and IHBD were 57%, 100%, 64%, and 100% for MRCP; 82%, 77%, 95%, and 32% for ERCP; 25%, 75%, 21%, and 85% for DIC-CT; and 87%, 100%, 87%, and 100% for IOCP, respectively. Combination of MRCP and IOCP achieved rates of 89%, 100%, 91%, and 100%, respectively. Sensitivity, specificity, and accuracy for detecting stenosis were 86%, 68%, and 71% for MRCP, and 100%, 89%, and 91% for IOCP, respectively. CONCLUSIONS: Combining MRCP and IOCP can provide satisfactory pancreaticobiliary anatomical information for surgical planning for pediatric CC, with hepatic duct strictures evaluated more accurately by IOCP.

Antibody-dependent cellular cytotoxicity toward neuroblastoma enhanced by activated invariant natural killer T cells.

Anti-ganglioside GD2 antibodies mainly work through antibody-dependent cellular cytotoxicity (ADCC) and have demonstrated clinical benefit for children with neuroblastoma. However, high-risk neuroblastoma still has a high recurrence rate. For further improvement in patient outcomes, ways to maximize the cytotoxic effects of anti-GD2 therapies with minimal toxicity are required. Activated invariant natural killer T (iNKT) cells enhance both innate and type I acquired anti-tumor immunity by producing several kinds of cytokines. In this report, we investigated the feasibility of combination therapy using iNKT cells and an anti-GD2 antibody. Although some of the expanded iNKT cells expressed natural killer (NK) cell markers, including FcγR, iNKT cells were not directly associated with ADCC. When co-cultured with activated iNKT cells, granzyme A, granzyme B and interferon gamma (IFNγ) production from NK cells were upregulated, and the cytotoxicity of NK cells treated with anti-GD2 antibodies was increased. Not only cytokines produced by activated iNKT cells, but also NK-NKT cell contact or NK cell-dendritic cell contact contributed to the increase in NK cell cytotoxicity and further IFNγ production by iNKT cells and NK cells. In conclusion, iNKT cell-based immunotherapy could be an appropriate candidate for anti-GD2 antibody therapy for neuroblastoma.

Risk Factors for Intestinal Obstruction After Ladd Procedure.

Intestinal obstruction is a common complication after Ladd procedure. Ninety-three cases who had undergone the Ladd procedure between 1977 and 2013 treated at our own institution were retrospectively reviewed to identify the causes and risk factors for intestinal obstruction. The Ladd procedure has been performed without any intestinal fixing. Of the 87 cases who survived to discharge, intestinal obstruction was observed in 22 (25.3%). Among the cases with intestinal obstruction, 13 (59.1%) showed intestinal ischemia at the initial operation; this incidence was notably high, although it is low when only those cases with another concurrent surgical digestive disease are considered. All cases of intestinal obstruction were caused not by recurrent volvulus, but by adhesion between the intestine and the mesentery. Intestinal fixing is not required to prevent recurrent volvulus, but it is important to achieve adequate widening of the mesenteric base. The risk of intestinal obstruction after the Ladd procedure, on the other hand, is high. Moreover, patients with intestinal ischemia have an increased risk of intestinal obstruction.

Evidence for viral infection as a causative factor of human biliary atresia.

OBJECTIVES: To explore the evidence for viral infections triggering human biliary atresia (BA) by reviewing archival original articles that analyzed human samples via polymerase chain reaction (PCR) experiments, considering the recent experimental trend of extensive use of rotaviral BA animal models. METHODS: A PubMed search retrieved original articles that reported the results of PCR experiments for detecting viral DNA or RNA in patient samples as proof of past infection. Search terms included the often-debated DNA or RNA viruses and BA. Special focus was directed toward PCR analyses that targeted reovirus and rotavirus, where PCR accuracy, specimen characteristics and their interpretations were compared. RESULTS: Nineteen studies were conducted on 16 different kinds of viruses using PCR, with 5 studies on reovirus, 3 on rotavirus, 10 on cytomegalovirus, 5 on Epstein-Barr virus, 4 on parvovirus B19, and so on. Among the papers suggesting a possible viral link to only BA, there was no study on reovirus, 1 on rotavirus, 3 on cytomegalovirus, 1 on EB virus, and 1 on papillomavirus. Of the 6 PCR studies on Reoviridae, 3 on reovirus and 2 on rotavirus were evaluated rigorously for experimental accuracy, including their sensitivity. Two research groups analyzed preoperative stool samples in addition to generic hepatobiliary tissue obtained at surgery. Sample collection timing varied widely, with storage period prior to PCR experimentation not revealed in most reports on Reoviridae. CONCLUSION: Although a considerable number of PCR studies have sought to clarify a viral role in the pathogenesis of BA using human samples, the findings have been contradictory and have not succeeded in achieving an obvious differentiation between causative and accidental infection of the focused virus. Reproducible and convincing evidence for a causative Reoviridae infection has been lacking based on objective data from highly sensitive PCR experiments. Even though the possibility remains of viral disappearance at the timing of collection, to avoid further ambiguous interpretations of PCR results, rigorous and meticulous collection of large numbers of specimens at carefully planned timing, along with a strictly adjusted and finely tuned PCR system, is strongly recommended for obtaining more reliable and consistent results.

Malignant rhabdoid tumor of the liver: a case report and literature review.

Malignant rhabdoid tumor (MRT) is a rare and aggressive malignancy associated with poor outcomes. MRT of the liver is even rarer, and little information has been described. We report the case of an 8-month-old boy with MRT of the liver. The tumor showed aggressive progression despite a multidisciplinary approach, and the patient died due to multiple organ failure 14 days after admission. Autopsy revealed the liver tumor and multiple metastases with negative immunohistochemistry for INI1/BAF47. A review of 53 cases of pediatric MRT of the liver is provided.