Masato Abe

Fujita Health University, Nagoya, Aichi, Japan

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Publications (7)11.46 Total impact

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    ABSTRACT: Genetic subgrouping of gliomas has been emphasized recently, particularly after the finding of isocitrate dehydrogenase 1 (IDH1) mutations. In a previous study, we investigated whole-chromosome copy number aberrations (CNAs) of gliomas and have described genetic subgrouping based on CNAs and IDH1 mutations. Subsequently, we classified gliomas using simple polymerase chain reaction (PCR)-based methods to improve the availability of genetic subgrouping. We selected IDH1/2 and TP53 as markers and analyzed 237 adult supratentorial gliomas using Sanger sequencing. Using these markers, we classified gliomas into three subgroups that were strongly associated with patient prognoses. These included IDH mutant gliomas without TP53 mutations, IDH mutant gliomas with TP53 mutations, and IDH wild-type gliomas. IDH mutant gliomas without TP53 mutations, which mostly corresponded to gliomas carrying 1p19q co-deletions, showed lower recurrence rates than the other 2 groups. In the other high-recurrence groups, the median progression-free survival (PFS) and overall survival (OS) of patients with IDH mutant gliomas with TP53 mutations were significantly longer than those of patients with IDH wild-type gliomas. Notably, most IDH mutant gliomas with TP53 mutations had at least one of the CNAs +7q, +8q, −9p, and −11p. Moreover, IDH mutant gliomas with at least one of these CNAs had a significantly worse prognosis than did other IDH mutant gliomas. PCR-based mutation analyses of IDH and TP53 were sufficient for simple genetic diagnosis of glioma that were strongly associated with prognosis of patients and enabled us to detect negative CNAs in IDH mutant gliomas.
    No preview · Article · Nov 2015 · PLoS ONE
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    ABSTRACT: Purpose: Neuroepithelial cyst is considered an unusual differential diagnosis for cysts in the posterior fossa. Here, we present a paediatric case with such a pathology and review the pertinent literature. Methods: A 12-year old girl with headache, vertigo and disturbed gait was diagnosed with a cystic lesion in the fourth ventricle after brain MRI study. She was operated with the pre-operative diagnosis of arachnoid cyst. Results: A transparent, colourless cyst was observed intra-operatively. As frozen sections were consistent with endodermal cyst, total removal of the cyst was attempted. Definite histopathological studies and immunohistochemistry stains were in favour of neuroepithelial cyst. No regrowth of the cyst or recurrence of the symptoms was observed in her 2-year follow-up. Conclusions: As neuroepithelial cyst is rarely encountered in the posterior fossa, the clinical, radiological and pathological characteristics of our case along with similar cases in the literature were reviewed and discussed.
    No preview · Article · Jul 2014 · Child s Nervous System

  • No preview · Article · Dec 2013 · Neurosurgical Review
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    ABSTRACT: A rare case of ancient schwannoma originating from subfrontal region is reported. A 39-year-old woman underwent a medical checkup of the brain and her magnetic resonance imaging revealed a well-circumscribed mass with cystic change in the left subfrontal region. H magnetic resonance spectroscopy, positron emission tomography, and perfusion computed tomography failed to reveal any malignant findings. Total removal of the tumor by subfrontal approach was performed. Pathologic evaluation revealed strongly suggestive findings of ancient schwannoma, a rare variant of schwannoma. Subfrontal schwannoma is uncommon; especially, that with ancient change is further rare, and, herein, its neuroradiologic and histologic features are discussed.
    No preview · Article · Aug 2013 · Neurosurgery Quarterly
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    ABSTRACT: Management of gliomas depends on histological diagnosis; there are, however, limitations to the systems presently used. Tumors in the same entity can have different clinical courses, especially when they are diagnosed as WHO grade II-III. Previous studies revealed that genetic subgrouping of gliomas provides useful information that could help establishment of treatment procedures on the basis of the genetic background of the tumors. Recently, the authors analyzed the chromosomal copy number aberrations (CNAs) of adult supratentorial gliomas by comparative genomic hybridization using microdissected tissue sections. The tumors were classified into subgroups according to chromosomal CNAs. WHO grade II-III gliomas contained a variety of genetic subgroups that correlated well with the clinical course. Of these, long progression-free survival was observed for tumors with +7q and those with -1p/19q, low-grade tumors of 2 major lineages, and, in our preliminary data, both were closely correlated with mutation of IDH1. Furthermore, in contrast with +7q tumors, the great majority of +7 or +7/-10q groups had wildtype IDH1. Genetic studies suggest that cytogenetic characterization may provide an additional classification system for gliomas, and new criteria could help to establish rational and objective means for analysis of treatment procedures.
    No preview · Article · Apr 2013 · Brain Tumor Pathology
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    ABSTRACT: Cancers metastatic to the skull or dura may cause subdural hematoma (SDH). However, the frequency is low, and the presence of underlying cancers has almost always been known in such situations. We report a case of skull angiosarcoma manifesting as SDH, posing a diagnostic challenge to physicians. A 75-year-old man visited our clinic with sensorimotor disturbance of gradual onset approximately 1 month after a minor head trauma. He was diagnosed with SDH after imaging studies, and underwent surgery to evacuate the hematoma. Because the hematoma was organized, surgery was switched from burr-hole drainage to craniotomy. The bone flap as well as the dura over the hematoma had grossly normal appearance, and only the hematoma itself was submitted for histological examination. Although postoperative recovery was uneventful, the patient experienced recurrence of the SDH 2 months after surgery. At the second surgery, the bone flap and dura were intermingled with tumor tissue, and histological examination revealed that an epithelioid angiosarcoma originating from the skull was responsible for the SDH. Timely diagnosis of angiosarcoma manifesting as SDH is difficult because of its rarity. In retrospect, however, the diagnosis might have been established earlier if the bone flap and/or the dura had been biopsied at the time of the first surgery. The present case gives us a lesson that SDH may be an unusual manifestation of malignant tumors of skull or dural origin, and histological examination of not only hematoma capsule but also of the surrounding tissues may provide important diagnostic clues.
    No preview · Article · Jul 2012 · Head and Neck Pathology
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    ABSTRACT: Gliomas are classified into pathologically defined subgroups. However, the tumors in the same entity could show varied 'clinical courses. Recently, various studies revealed that genetic analyses of gliomas can provide clinically relevant information. To investigate the correlation between genetic characterization and clinical information of adult supratentorial grade II-III gliomas to establish a genetic classification of these tumors. We analyzed the genetic profile of tumor samples microdissected from formalin-fixed archival tissue sections based on the defined selection criteria of tumor region using a comparative genomic hybridization method. We collected genetic and clinical data from 140 adult supratentorial gliomas of World Health Organization grade II-III and classified the tumors analyzed into subgroups according to chromosomal copy number aberrations. The relationship between histologic or genetic subclassification and clinical features was analyzed. The tumors were classified into subgroups based on the genetic profiles. Tumors with +7q and those with -1p/19q showed long progression-free survival, and loss of 10q in association with gain of 7p (+7/-10q) appeared to predict poor outcome. Most tumors with histologic diagnosis of glioblastoma showed +7/-10q; however, World Health Organization grade II-III gliomas contained a variety of genetic subgroups that correlated well with the clinical course, and this might explain why these tumors do not respond uniformly to therapies. Our pilot study suggests that care must be taken in clinical studies of these tumors because, unlike glioblastoma, grade II-III tumors may contain genetically distinct subgroups with different sensitivity to the therapies.
    No preview · Article · Feb 2011 · Neurosurgery