Hyperplasia of Arachnoid Trabecular Cells: A Hitherto Undescribed Lesion Observed in the Setting of Neurofibromatosis Type 1.

Central nervous system manifestations, a variety of benign and malignant tumors as well as non-neoplastic abnormalities, are found in over 70% of neurofibromatosis type 1 (NF1) patients. Herein, we report hitherto undescribed space-occupying lesions in the setting of NF1. We aimed to clarify their characteristics, especially whether they represent neoplastic or non-neoplastic (hyperplastic) lesions. All 3 cases were preoperatively assessed as non-neoplastic; 2 and 1 cases were suspected to be arachnoid cysts and dilation of subarachnoid space, respectively. However, all lesions were revealed to be whitish jelly-like masses by operation, and the histology composed of spindle cells resembling arachnoid trabecular cells with moderate cellularity and cellular uniformity gave an impression that these lesions may be neoplastic. In contrast, electron microscopic analysis showed that the characteristics of these cells were compatible with those of normal arachnoid trabecular cells. Furthermore, whole-exome sequencing and array comparative genomic hybridization did not show any obvious alterations suggestive of their neoplastic nature. DNA methylation analysis demonstrated that these lesions were epigenetically distinct not only from meningiomas but also from normal healthy meninges. In conclusion, considering the clinicopathologic aspects of the present lesions and the results of the molecular analysis that failed to suggest their neoplastic nature, they may represent previously unrecognized rare hyperplasia of arachnoid trabecular cells, which may be associated with NF1.

Analysis of clinicopathological features and NAB2-STAT6 fusion variants of meningeal solitary fibrous tumor with ectopic salivary gland components in the cerebellopontine angle.

Solitary fibrous tumors (SFTs) are rare mesenchymal tumors that can occur at any location. Since the identification of specific NAB2-STAT6 fusion in SFTs, the fusion gene variants, NAB2 exon 4-STAT6 exon 2/3 and NAB2 exon 5/6/7-STAT6 exon 16/17/18, have been reported to be associated with clinicopathological features, and the latter variant is predominant in meningeal SFTs. SFTs developing in the salivary glands are rare, and more rarely, those involving ectopic salivary glands (ESGs) have been reported in the cerebellopontine angle (CPA); however, their characteristics remain not well understood. In this study, we performed a clinicopathological and molecular analysis of 3 cases of meningeal SFT with ESGs. All cases presented with an extra-axial mass in the CPA, which is a rarer location for intracranial ESGs compared to the sellar region. Histologically, except for the presence of ESGs, there was no significant difference between current cases and ordinary SFTs. The ESGs demonstrated no cellular atypia, and although the spindle tumor cells were immunopositive for STAT6, the ESGs were negative in all cases, supporting that the ESGs are non-neoplastic components. In 1 case, ESGs were found only in the primary tumor and disappeared in recurrence/dissemination. Of note, molecular analysis identified NAB2 exon 4-STAT6 exon 2 in all cases. In conclusion, our results suggest that ESGs particularly in the CPA may be associated with SFTs and that meningeal SFTs with ESGs may be associated with the minor fusion variant of NAB2-STAT6 in the intracranial lesions.

Preoperative portal vein embolization: a comparison of ethanol and coils versus ethanol alone.

PURPOSE: To compare the efficacy and safety of preoperative portal vein embolization (PVE) with ethanol and coils versus ethanol alone. MATERIAL AND METHODS: Between April 2014 and May 2019, 45 patients underwent right preoperative PVE with ethanol and coils (n = 19; EthCo group) or ethanol alone (n = 26; Eth group). RESULTS: The change in % future liver remnant (FLR) was not significantly different between the EthCo and Eth groups (11.2 ± 4.3% versus 11.3 ± 4.1%, p = .98). Less ethanol was used in the EthCo group (9.7 ± 3.5 mL versus 11.9 ± 4.4 mL, p = .02). Recanalization was observed in eight patients only in the Eth group (p < .01). There were no differences in the pre-/post-PVE laboratory data between the two groups, except for post-PVE albumin. The volume of ethanol used was positively correlated with the post-PVE total bilirubin (p = .01), aspartate aminotransferase (AST) (p < .01) and alanine aminotransferase (ALT) (p < .01) levels. CONCLUSION: The efficacy of PVE did not differ between the EthCo and Eth groups. The use of ethanol and coils was associated with less recanalization and liver damage compared with ethanol alone.

Ependymoma-like tumor with mesenchymal differentiation harboring C11orf95-NCOA1/2 or -RELA fusion: A hitherto unclassified tumor related to ependymoma.

Recurrent fusion genes involving C11orf95, C11orf95-RELA, have been identified only in supratentorial ependymomas among primary CNS tumors. Here, we report hitherto histopathologically unclassifiable high-grade tumors, under the tentative label of "ependymoma-like tumors with mesenchymal differentiation (ELTMDs)," harboring C11orf95-NCOA1/2 or -RELA fusion. We examined the clinicopathological and molecular features in five cases of ELTMDs. Except for one adult case (50 years old), all cases were in children ranging from 1 to 2.5 years old. All patients presented with a mass lesion in the cerebral hemisphere. Histologically, all cases demonstrated a similar histology with a mixture of components. The major components were embryonal-appearing components forming well-delineated tumor cell nests composed of small uniform cells with high proliferative activity, and spindle-cell mesenchymal components with a low- to high-grade sarcoma-like appearance. The embryonal-appearing components exhibited minimal ependymal differentiation including a characteristic EMA positivity and tubular structures, but histologically did not fit with ependymoma because they lacked perivascular pseudorosettes, a histological hallmark of ependymoma, formed well-delineated nests, and had diffuse and strong staining for CAM5.2. Molecular analysis identified C11orf95-NCOA1, -NCOA2, and -RELA in two, one, and two cases, respectively. t-distributed stochastic neighbor embedding analysis of DNA methylation data from two cases with C11orf95-NCOA1 or -NCOA2 and a reference set of 380 CNS tumors revealed that these two cases were clustered together and were distinct from all subgroups of ependymomas. In conclusion, although ELTMDs exhibited morphological and genetic associations with supratentorial ependymoma with C11orf95-RELA, they cannot be regarded as ependymoma. Further analyses of more cases are needed to clarify their differences and similarities.

CNS Low-grade Diffusely Infiltrative Tumors With INI1 Deficiency, Possessing a High Propensity to Progress to Secondary INI1-deficient Rhabdoid Tumors.

Atypical teratoid/rhabdoid tumors (AT/RTs) are highly malignant tumors of the central nervous system that predominantly occur in infants, and are characterized by the presence of rhabdoid cells and inactivation of INI1 or (rarely) BRG1. Most AT/RT are identified as primary tumors; however, rare AT/RT or INI1-deficient RTs arising from other primary tumors have been reported. Here, we report 3 cases of hitherto unclassifiable low-grade tumors with loss of INI1 nuclear expression, for which we propose the designation of central nervous system low-grade diffusely infiltrative tumors with INI1 deficiency (CNS LGDIT-INI1), 2 of which progressed to secondary RT. All 3 CNS LGDIT-INI1 exhibited a similar histology: diffusely distributed small tumor cells with round to oval or irregular nuclei and scant cytoplasm were admixed with degenerative neurons and large reactive astrocytes in an edematous, myxoid, or collagenous background. Mitotic figures were absent. Immunohistochemistry revealed that the tumor cells in all 3 CNS LGDIT-INI1 and 2 RT were negative for INI1. Genetically, total or partial homozygous deletions of the INI1 gene were detected in all CNS LGDIT-INI1 and RT excluding 1 CNS LGDIT-INI1 without sufficient DNA quality and quantity. Despite the loss of INI1 expression, these low-grade lesions were clearly distinguishable from AT/RT by their low proliferative activity, diffusely infiltrative growth pattern, and lack of rhabdoid cells and polyphenotypic immunoreactivity. In conclusion, CNS LGDIT-INI1 may represent a rare group of tumors that are clinically indolent but have a high propensity to progress to RT.

Utility of hepatic vein waveform and transient elastography in patients with Budd-Chiari syndrome who require angioplasty: Two case reports.

RATIONALE: Budd-Chiari syndrome (BCS), which causes congestive hepatopathy and aggravates cirrhosis, is typically treated by interventional angioplasty to ameliorate blood flow. X-ray venography is useful for the evaluation of inferior vena cava (IVC) stenosis and determination of treatment timing, but it is invasive and thus unsuitable for repeated examinations. The development of a simple method for the prediction of IVC stenosis would reduce the burden on patients with BCS. PATIENT CONCERNS: We report here our experience of 2 patients with BCS who underwent percutaneous transluminal angioplasty (PTA). The first patient was a 39-year-old male who underwent PTA to expand his stenotic IVC. The second patient was a 19-year-old male who underwent PTA 3 times due to restenosis of his IVC. DIAGNOSES: Both patients were diagnosed with BCS with severe obstruction of the IVC. INTERVENTIONS: We evaluated the hepatic vein (HV) waveform by Doppler ultrasonography and measured liver stiffness (LS) using transient elastography (TE) before and after PTA. OUTCOMES: In case 1, the phasic oscillation of the HV waveform recovered and the LS value decreased after PTA. Both improvements were maintained for ∼3 years, reflecting the long-term patency of the IVC. In case 2, the HV waveform and the LS value improved temporarily after PTA, but then deteriorated gradually. Monitoring of the HV waveform and LS value allowed retreatment prior to total occlusion of the IVC and abrogated the risk of intravascular needle puncture. LESSONS: Monitoring of the HV waveform and the LS value enables safe management of patients with BCS who may require PTA.

Genetic polymorphism of Japanese cultivated Rheum species in the internal transcribed spacer region of nuclear ribosomal DNA.

In order to develop new domestic production of Rhei Rhizoma (RR) from Rheum specimens cultivated in the Sugadaira Medicinal Plant Cultivation Test Field (SMPCF), the ITS sequences of 12 SMPCF specimens and Chinese Rheum specimens of four species, as well as RR samples produced in North Korea, China and Japan, were determined by subcloning and their sequences were compared. As the ITS sequences of 10 SMPCF specimens showed significant intra-individual polymorphism, identification of pseudogenes was conducted by detecting the three motifs of the 5.8S sequence and the stability of the 5.8S secondary structure. Approximately 46% of sequences obtained from the SMPCF specimens were putative pseudogenes. The maximum likelihood tree based on ITS sequences showed three main groups-the outer group and inner clusters I and II; clones from 10 SMPCF specimens including putative pseudogenes belonged to the outer group. Cluster I was composed of two clades, one including clones from R. officinale specimens and R. palmatum-derived samples with matK genotype Rp9, and another including clones from R. coreanum-derived samples. Cluster II consisted of three clades, one including clones from R. palmatum specimens with genotype Rp5, another including clones mainly from R. tanguticum specimens with genotype Rt4, and the third including clones from R. palmatum or R. tanguticum specimens with various matK genotypes. Clones from SMPCF specimen RC5 showed a close relationship with those from R. tanguticum specimens with matK genotype Rt4, whereas those from specimen RC9 related to R. coreanum-derived samples. As a result, specimens RC5 and RC9 were considered as candidates for the development of domestic RR.

Influence of outflow-obstructed liver volume and venous communication development: A three-dimensional volume study in living donors.

Living donor liver transplantation using the left liver graft with the middle hepatic vein (MHV) is a well-established procedure. Following such procedures, outflow obstruction occurs in remnant livers. However, the effects of the outflow-obstructed liver volume (LVOut-Ob ), with or without venous communication development, remain unclear. The aim of the study is to investigate effects of outflow-obstructed regions by focusing on short-term outcomes and remnant liver hypertrophy in left liver procurement donors. Of 532 donors, we collected data from 119 undergoing left liver procurement with the MHV. Postoperative hepatic parameters, venous communication development, and liver hypertrophy were evaluated in 2 donor groups based on LVOut-Ob . The left liver was procured with the MHV in 119 donors, who formed 2 more groups based on the median LVOut-Ob : large-outflow-obstruction group (n = 60; LVOut-Ob ≥ 263 mL) and small-outflow-obstruction (n = 59; LVOut-Ob < 263 mL) group. Postoperative liver function parameters were significantly impaired in the large-outflow-obstruction group compared with the small-outflow-obstruction group. Postoperative venous communication developed in 52 (66.7%) of 78 donors analyzed. Hypertrophy ratios in remnant right livers and right paramedian sectors were significantly higher in the small-outflow-obstruction group than in the large-outflow-obstruction group (P = 0.01 and P = 0.02, respectively). The liver hypertrophy ratio of outflow-obstructed regions was better, especially in small regions developing venous communication (P = 0.001). The postoperative morbidity rate did not differ significantly (P = 0.66). In conclusion, the procurement of the left liver graft with the MHV was safely performed with minimal morbidity by assessing the donor remnant right liver volume with and without outflow obstruction. Attention should be paid that postoperative hepatic parameters and remnant liver hypertrophy were impaired in the remnant livers with large outflow-obstructed regions compared with those with small outflow-obstructed regions. Liver Transplantation 23 1531-1540 2017 AASLD.

Clinical Impact of Preoperative Chemotherapy on Microscopic Cancer Spread Surrounding Colorectal Liver Metastases.

BACKGROUND: A potentially favorable effect of chemotherapy on the incidence of micrometastases has been reported in patients with colorectal liver metastases (CLMs); however, the actual influence of chemotherapy on the distribution of micrometastases and surgical curability remains unclear. METHOD: The clinical impact of preoperative chemotherapy on the incidence and distribution of micrometastases was assessed in 191 patients with 357 CLM nodules. Potential radiologic measures for predicting the extent of microscopic cancer spread and surgical curability were then sought among the size-based and non-size-based radiologic response criteria. RESULTS: Multivariate analysis estimated a reduced incidence of micrometastases in patients receiving preoperative chemotherapy (odds ratio [OR] 0.45, 95% confidence interval [CI] 0.26-0.76, p = 0.003). Furthermore, the addition of biologic agents to the preoperative chemotherapy regimen was correlated with a reduced incidence of microscopic cancer spread beyond a width of 1 mm from the margin of the main tumor (OR 0.28, 95% CI 0.11-0.74, p = 0.010 for bevacizumab; and OR 0.29, 95% CI 0.09-0.99, p = 0.048 for anti-epidermal growth factor receptor antibody). Receiver operating characteristic analyses revealed that the computed tomography (CT) morphologic response showed a moderate predictive power for the distribution of micrometastases, with an area under the curve of 0.687, while size-based response criteria were not reliable for estimating the extent of microscopic cancer spread. CONCLUSION: Notwithstanding the potential selection of patients after preoperative chemotherapy, the incidence and distribution of micrometastases may be reduced by preoperative chemotherapy. CT morphologic response may be a reliable predictor of both the degree of microscopic cancer spread and the curability of surgery.

Primary hepatic schwannoma: A case report.

INTRODUCTION: A hepatic schwannoma is extremely rare and difficult to diagnose preoperatively. PRESENTATION OF CASE: We report the case of a 47-year-old male patient who was referred to our hospital for the close investigation of a hepatic tumor which had not been detected two years earlier. An enhanced computed tomography revealed a well-circumscribed and encapsulated tumor with a size of 50mm which was adjacent to the inferior vena cava (IVC) and the right hepatic vein. The tumor was heterogeneously enhanced until the equilibrium phase. A magnetic resonance image showed a hypointense area on a T1-weighted image and a hyperintense area on a T2-weighted image. These findings differed from those of common malignant hepatic tumors, such as hepatocellular carcinoma and colorectal liver metastases. The tumor was most likely a mucus-producing tumor or a liquefactive degenerated adenocarcinoma. Although we could not confirm an exact diagnosis of the tumor, we performed a surgical resection in view of the possibility of malignancy. The patient underwent a limited liver resection with resection of the IVC. Histologically, the tumor was diagnosed as a benign schwannoma comprised of Antoni A and B areas. The nuclear palisading formation of the tumor showed Verocay bodies. DISCUSSION: 15 cases of hepatic schwannoma are reviewed to clarify the typical radiological features. The radiological findings of the present case were consistent with those of the hepatic schwannoma when considering retrospectively. CONCLUSION: A precise preoperative diagnosis of hepatic schwannoma is difficult, and liver resection is recommended when a hepatic schwannoma is suspected.

Atypical Teratoid/Rhabdoid Tumor (AT/RT) Arising From Ependymoma: A Type of AT/RT Secondarily Developing From Other Primary Central Nervous System Tumors.

Atypical teratoid/rhabdoid tumors (AT/RT) are rare, aggressive, embryonal brain tumors that occur most frequently in very young children; they are characterized by rhabdoid cells and loss of INI1 protein nuclear expression. Here, we report the case of a 24-year-old man with a left frontal lobe tumor that was composed mainly of rhabdoid cells showing loss of INI1 nuclear reactivity and polyphenotypic immunohistochemical expression, with a small INI1-positive component of ependymoma. Array comparative genomic hybridization separately conducted for each histologically distinct component revealed 22 shared identical copy number alterations, including loss of heterozygosity of chromosome 22q containing the INI1 locus. Furthermore, we found the C11orf95-RELA fusion gene, the genetic hallmark of supratentorial ependymomas, not only in the ependymoma component but also in the AT/RT component by fluorescence in situ hybridization analysis, suggesting that the AT/RT cells secondarily progressed from the preexisting ependymoma cells. A second genetic inactivating event in the INI1 gene was not detected in the AT/RT component. There are several reported cases of AT/RT (or INI1-negative rhabdoid tumors) arising in the setting of other primary brain tumors (gangliogliomas, pleomorphic xanthoastrocytomas, and high-grade gliomas), but the present case

Radiological Morphology of Colorectal Liver Metastases after Preoperative Chemotherapy Predicts Tumor Viability and Postoperative Outcomes.

INTRODUCTION: The computed tomography (CT) morphology after chemotherapy is reportedly correlated with the histopathologic response to chemotherapy and a better surgical outcome in patients with colorectal liver metastases (CLM). However, the true prognostic advantage of CT morphology remains uncertain. METHODS: The prognostic advantage of CT morphology was validated in 86 patients who underwent surgical resection for CLM after undergoing a 5-fluorouracil-based chemotherapy regimen with or without bevacizumab. RESULTS: An optimal morphologic response was observed in 18 (22.8%) patients, and a strong correlation between the CT morphology and tumor viability was confirmed (P < 0.001). A multivariate analysis revealed that bevacizumab (odds ratio [OR], 6.8; P = 0.03) and chemotherapy cycles ≥6 (OR, 3.6; P = 0.04) were associated with an optimal morphologic response. Overall survival (OS) and recurrence-free survival (RFS) were also predicted by CT morphology with a higher sensitivity. Particularly, a group 1 morphology was associated with a higher OS rate (3-year OS 100%) and RFS rate (3-year RFS, 57.0%), and a multivariate analysis confirmed that group 2 and group 3 tumor morphology was a significant predictive factor for tumor recurrence (hazard ratio [HR], 2.5; P = 0.03 and HR, 3.2; P < 0.01, respectively). CONCLUSION: The CT morphology of CLM predicts tumor viability and long-term surgical outcomes after chemotherapy.

Intratumoral heterogeneity of genomic imbalance in a case of epithelioid glioblastoma with BRAF V600E mutation.

Epithelioid glioblastoma is among the rarest variants of glioblastoma and is not formally recognized in the World Health Organization classification; it is composed of monotonous, discohesive sheets of small, round cells with eccentric nuclei and eosinophilic cytoplasm devoid of cytoplasmic stellate processes, showing the retention of nuclear staining of INI-1 protein. Here, we report a case involving a 22-year-old man with a right occipital lobe tumor, which comprised mainly epithelioid tumor cells with a small area of diffusely infiltrating less atypical astrocytoma cells showing a lower cell density. Array comparative genomic hybridization separately performed for each histologically distinct component demonstrated eight shared copy number alterations (CNAs) and three CNAs observed only in epithelioid cells; one of the latter was a homozygous deletion of a tumor suppressor gene, LSAMP, at 3q13.31. BRAF V600E mutation was observed both in epithelioid tumor cells and in diffusely infiltrating less atypical astrocytoma cells. Our findings suggest that the regional loss of LSAMP led to the aggressive nature of epithelioid cells in the present case of epithelioid glioblastoma.

Santorinicele without pancreas divisum pathophysiology: initial clinical and radiographic investigations.

BACKGROUND: Only one case of santorinicele without pancreas divisum pathophysiology (SWOPP) was previously reported. The purpose of the study was to determine the gross prevalence of SWOPP and santorinicele with pancreas divisum (SWPD) in community and patient populations, and investigate their clinical and radiographic features. METHODS: This cross-sectional study was performed at a tertiary referral centre. The Patient group comprised 2035 consecutive patients enrolled in the study who underwent magnetic resonance cholangiopancreatography (MRCP) studies. The Community group comprised 2905 consecutive subjects who participated in our whole-body medical check-up program that routinely includes MRCP studies. SWOPP was diagnosed when a saccular dilatation of the terminal portion of the dorsal pancreatic duct was observed unaccompanied by pancreas divisum or dominant dorsal duct. The prevalence of SWOPP and SWPD, and the clinical and radiological features were assessed in each group. RESULTS: Five cases of SWOPP were found in the Patient group (age range, 67-85 years; mean age, 73.6 years) (5/2035 = 0.25%; 95% confidence interval, 0.07-0.57); there were no cases of SWOPP in the Community group (0/2905 = 0.00%; 95% confidence interval, 0.00-0.10) (P = 0.01). Previous history of pancreatitis (4/5) and chronic pancreatitis (3/5) was more common in patients with SWOPP than in other subjects in the Patient or Community groups (both P < 0.05). Two cases of SWOPP were accompanied by reverse-Z type meandering main pancreatic duct. Six cases of SWPD were found. These cases were asymptomatic in 4/6, had a larger santorinicele (6.9 mm) than SWOPP patients (4.5 mm; P = 0.02), and were not associated with pancreatitis (0/6). CONCLUSIONS: The second to sixth reported cases of SWOPP were presented. SWOPP is a relatively rare condition found mostly in patients suffering pancreatitis, especially chronic pancreatitis, and may be an acquired condition. Santorinicele is not always accompanied by pancreas divisum.

Sudden death as a late sequel of Kawasaki disease: postmortem CT demonstration of coronary artery aneurysm.

Kawasaki disease (KD) is an acute, self-limited vasculitis of unknown etiology that primarily affects the coronary artery (CA) and presents during childhood. The characteristic coronary arterial lesion of KD is an aneurysm. Ischemic heart disease derived from a CA aneurysm is experienced approximately two decades after the onset of acute KD. In recent years, the primary issue of concern has been asymptomatic adults with a CA aneurysm caused by undiagnosed KD. We present a case of sudden death as a late KD sequel in a young adult. A postmortem CT scan revealed a coarse calcification of a left anterior descending CA aneurysm, which was confirmed at the time of autopsy. A postmortem CT scan is useful in cases of sudden death where the detection of a calcified CA aneurysm would suggest to the forensic pathologist that the deceased suffered from a late sequel of KD. The use of screening postmortem CT scans for young people may detect cases of unsuspected CA aneurysms, raising the possibility of untreated KD.

A case of retained placenta increta successfully treated via uterine arterial embolization using N-butyl 2-cyanoacrylate.

A 29-year-old woman with placenta increta with hemorrhage underwent uterine artery embolization using 12.5% NBCA (N-butyl 2-cyanoacrylate) diluted with iodized oil (Lipiodol). Complete resolution of placenta increta without performing curettage was obtained. The uterus returned to its normal shape, with restored endometrium, junctional zone, and myometrium. Menstruation resumed after 3 months. In cases of retained placenta due to placenta accreta, and even those with placenta increta, uterine artery embolization using NBCA is a useful treatment.

Meandering main pancreatic duct as a relevant factor to the onset of idiopathic recurrent acute pancreatitis.

BACKGROUND: Meandering main pancreatic duct (MMPD), which comprises loop type and reverse-Z type main pancreatic duct (MPD), has long been discussed its relation to pancreatitis. However, no previous study has investigated its clinical significance. We aimed to determine the non-biased prevalence and the effect of MMPD on idiopathic pancreatitis using non-invasive magnetic resonance (MR) technique. METHODS AND FINDINGS: A cross-sectional study performed in a tertiary referral center. The study enrolled 504 subjects from the community and 30 patients with idiopathic pancreatitis (7 acute, 13 chronic, and 10 recurrent acute). All subjects underwent MR scanning and medical examination. MMPD was diagnosed when the MPD in the head of pancreas formed two or more extrema in the horizontal direction on coronal images of MR cholangiopancreatography, making a loop or a reverse-Z shaped hairpin curves and not accompanied by other pancreatic ductal anomaly. Statistical comparison was made among groups on the rate of MMPD including loop and reverse-Z subtypes, MR findings, and clinical features. The rate of MMPD was significantly higher for all idiopathic pancreatitis/idiopathic recurrent acute pancreatitis (RAP) (20%/40%; P<0.001/0.0001; odds ratio (OR), 11.1/29.0) than in the community (2.2%) but was not higher for acute/chronic pancreatitis (14%/8%; P = 0.154/0.266). Multiple logistic regression analysis revealed MMPD to be a significant factor that induces pancreatitis/RAP (P<0.0001/0.0001; OR, 4.01/26.2). Loop/reverse-Z subtypes were found more frequently in idiopathic RAP subgroup (20%/20%; P = 0.009/0.007; OR, 20.2/24.2) than in the community (1.2%/1.0%). The other clinical and radiographic features were shown not associated with the onset of pancreatitis. CONCLUSIONS: MMPD is a common anatomical variant and might be a relevant factor to the onset of idiopathic RAP.

Analysis of chromosome 19q13.42 amplification in embryonal brain tumors with ependymoblastic multilayered rosettes.

Recently, it was reported that ependymoblastoma and embryonal tumor with abundant neuropil and true rosettes (ETANTR) show 19q13.42 amplification at a high frequency, suggesting that these tumors may constitute a single entity. As ependymoblastic rosettes are the most prominent features in both subtypes, embryonal tumor with multilayered rosettes (ETMR) was proposed, for which 19q13.42 amplification represents a specific molecular hallmark. However, ependymoblastic rosettes are not specific to ependymoblastoma and ETANTR, and are also found in a few other embryonal tumors as well as immature teratomas, and knowledge on 19q13.42 amplification in these tumors is limited. In this study, we performed fluorescence in situ hybridazation (FISH) analysis and differential polymerase chain reaction (PCR), and detected 19q13.42 amplification in three out of four ETANTR, one ependymoblastoma and one medulloepithelioma with ETANTR components, whereas none of the two atypical teratoid/rhabdoid tumors (AT/RT) with ependymoblastic rosettes nor two immature teratomas with developing neuroectodermal structures showed such amplification, suggesting that medulloepitheliomas would possibly be included in ETMR, and ependymoblastic rosettes in AT/RT do not signify that these tumors constitute ETMR. Also, we found C19MC rather than miR-371-373 was amplified in one ETANTR, suggesting that C19MC miRNA cluster seems to be more closely linked to the pathogenesis of ETMR.