Practical procedures for the integrated diagnosis of astrocytic and oligodendroglial tumors
AbstractThe publication of the 2016 World Health Organization Classification of Tumors of the Central Nervous System (2016 WHO CNS) represented a major change in the classification of brain tumors. However, many pathologists in Japan cannot diagnose astrocytic or oligodendroglial tumors according to the 2016 WHO CNS due to financial or technical problems. Therefore, the Japan Society of Brain Tumor Pathology established a committee for molecular diagnosis to facilitate the integrated diagnosis of astrocytic and oligodendroglial tumors in Japan. We created three levels of diagnoses: Level 1 was defined as simple histopathol...
Source: Brain Tumor Pathology - March 6, 2019 Category: Neurology Source Type: research
Next-generation whole exome sequencing of glioblastoma with a primitive neuronal component
AbstractGlioblastoma with a primitive neuronal component (GBM-PN) was renamed from glioblastoma with primitive neuroectodermal tumor-like component (GBM-PNET) in the new WHO classification of tumors of the central nervous system in 2016. GBM-PN is a rare variant of glioblastoma. There were not so many publications on the investigation of GBM-PN. We did whole exome sequencing for 11 GBM-PN cases and found that the percentage of TP53, PIK3CA, PIK3R1, or PTEN mutation in our GBM-PN cases (72.7%, 27.3%, 27.3%, and 27.3% respectively) was much higher than that in cases in TCGA GBM 2008, TCGA GBM 2013, and TCGA lower-grade gli...
Source: Brain Tumor Pathology - February 4, 2019 Category: Neurology Source Type: research
A rapidly fatal intracranial anaplastic hemangiopericytoma with de-novo dedifferentiation: emphasis on diagnostic recognition, molecular confirmation and discussion on treatment dilemma
We report a unique case of an intracranial anaplastic SFT/HPC with de-novo dedifferentiation, which pursued a rapidly fatal clinical course in a 41-year-old lady. The dedifferentiated component comprised a focal area of glandular formation with epithelial immunophenotype acquisition. The distinct biphasic pattern of the tumor imparted great diagnostic challenges to the pathologists. An increased awareness of SFT/HPCs with a diverse morphologic spectrum or even a biphasic histologic pattern is essential in working up such cases. We first attempted gamma knife radiosurgery in treating a recurrent dedifferentiated SFT/HPC; un...
Source: Brain Tumor Pathology - January 2, 2019 Category: Neurology Source Type: research
Immunohistochemical detection of ALK protein identifies APC mutated medulloblastoma and differentiates the WNT-activated medulloblastoma from other types of posterior fossa childhood tumors
AbstractExpression of theALK gene strongly correlates with the WNT-activated medulloblastomas, which are routinely identified by detection ofCTNNB1 mutation. However, some tumors have mutations in other thanCTNNB1 genes. Therefore, we investigated if ALK expression may identify WNT-activated tumors withoutCTNNB1 mutation. In addition, we examined if ALK expression may differentiate WNT-activated medulloblastoma from other malignant posterior fossa tumors. ALK expression was analyzed using immunohistochemistry (clone D5F3) in 70 patients with posterior fossa tumours. Among 55 medulloblastomas, 6 tumors showed ALK expression...
Source: Brain Tumor Pathology - December 6, 2018 Category: Neurology Source Type: research
The clinicopathological analysis of receptor tyrosine kinases in meningiomas: the expression of VEGFR-2 in meningioma was associated with a higher WHO grade and shorter progression-free survival
In conclusion, our study suggests that VEGFR-2 inhibitors might be one of the best candidates for molecular therapy against recurre nt meningiomas. (Source: Brain Tumor Pathology)
Source: Brain Tumor Pathology - December 5, 2018 Category: Neurology Source Type: research
Identification of a novel KLC1 –ROS1 fusion in a case of pediatric low-grade localized glioma
We describe a novelKLC1 –ROS1 fusion identified in a case of pediatric low-grade glioma. This was detected by RNA sequencing and confirmed by reverse-transcription PCR and fluorescent in situ hybridization. Immunohistochemical staining for ROS1 was positive in the tumor cytoplasm. In vitro analysis demonstrated the oncogenic activity of this fusion, which was suppressed by the ALK/ROS1 inhibitor, crizotinib. Our case and others suggest that various ROS1 fusions might be present in a subset of pediatric gliomas, which could be targeted for therapy. (Source: Brain Tumor Pathology)
Source: Brain Tumor Pathology - October 22, 2018 Category: Neurology Source Type: research
Molecular profiling of different glioma specimens from an Ollier disease patient suggests a multifocal disease process in the setting of IDH mosaicism
AbstractOllier disease (OD) and Maffucci syndrome are rare conditions due to a post-zygotic somatic mutation that results in mosaicism. In addition to enchondromas and hemangiomas, some of these patients also develop other unrelated tumors, such as gliomas, that harborIDH mutations, suggesting that anIDH mutation is a common genetic event in the tumorigenesis in this group of patients. We illustrate an interesting case of multifocalIDH-mutant astrocytomas in an OD patient with 8 years of follow-up. We first demonstrated identicalIDH mutations in the brain tumor samples from various locations in this patient, but differen...
Source: Brain Tumor Pathology - October 1, 2018 Category: Neurology Source Type: research
Anaplastic changes of diffuse leptomeningeal glioneuronal tumor with polar spongioblastoma pattern
AbstractDiffuse leptomeningeal glioneuronal tumor (DLGNT) is a rare glioneuronal neoplasm with oligodendroglioma-like cells confined in the subarachnoid spaces. A great majority of DLGNT are histologically low grade. However, some tumors show features of anaplasia with increased mitotic and proliferative activity. Due to the limited number of patients and inadequate clinical follow-up reported to date, the WHO classification does not yet assign a distinct WHO grade to this entity. Polar spongioblastoma pattern, in which bipolar cells are arranged in parallel with palisading nuclei, remains poorly understood about the patho...
Source: Brain Tumor Pathology - October 1, 2018 Category: Neurology Source Type: research
NRAS Q61K mutated diffuse leptomeningeal melanomatosis in an adult patient with a brief review of the so-called “forme fruste” of neurocutaneous melanosis
AbstractPrimary melanocytic tumors of central nervous system represent rare tumors arising from melanocytes of the leptomeninges. These neoplasms include focal forms like melanocytoma and primary malignant melanoma and diffuse forms like leptomeningeal melanocytosis and primary leptomeningeal melanomatosis. The clinical diagnosis remains challenging, with clinical and radiologic features overlapping with other more common diseases. Here we present a case of a 38 years old male with primary diffuse leptomeningeal melanomatosis with presence of aNRASQ61K mutation without features of neurocutaneous melanosis. (Source: Brain Tumor Pathology)
Source: Brain Tumor Pathology - October 1, 2018 Category: Neurology Source Type: research
Stromal cells of hemangioblastomas exhibit mesenchymal stem cell-derived vascular progenitor cell properties
In conclusion, s tromal cells of hemangioblastomas exhibit mesenchymal stem cell-derived vascular progenitor cell properties. (Source: Brain Tumor Pathology)
Source: Brain Tumor Pathology - October 1, 2018 Category: Neurology Source Type: research
Reviewers in 2018
(Source: Brain Tumor Pathology)
Source: Brain Tumor Pathology - September 5, 2018 Category: Neurology Source Type: research
Molecular profiling of different glioma specimens from an Ollier disease patient suggests a multifocal disease process in the setting of IDH mosaicism
AbstractOllier disease (OD) and Maffucci syndrome are rare conditions due to a post-zygotic somatic mutation that results in mosaicism. In addition to enchondromas and hemangiomas, some of these patients also develop other unrelated tumors, such as gliomas, that harborIDH mutations, suggesting that anIDH mutation is a common genetic event in the tumorigenesis in this group of patients. We illustrate an interesting case of multifocalIDH-mutant astrocytomas in an OD patient with 8 years of follow-up. We first demonstrated identicalIDH mutations in the brain tumor samples from various locations in this patient, but differen...
Source: Brain Tumor Pathology - August 29, 2018 Category: Neurology Source Type: research
NRAS Q61K mutated diffuse leptomeningeal melanomatosis in an adult patient with a brief review of the so-called “forme fruste” of neurocutaneous melanosis
AbstractPrimary melanocytic tumors of central nervous system represent rare tumors arising from melanocytes of the leptomeninges. These neoplasms include focal forms like melanocytoma and primary malignant melanoma and diffuse forms like leptomeningeal melanocytosis and primary leptomeningeal melanomatosis. The clinical diagnosis remains challenging, with clinical and radiologic features overlapping with other more common diseases. Here we present a case of a 38 years old male with primary diffuse leptomeningeal melanomatosis with presence of aNRASQ61K mutation without features of neurocutaneous melanosis. (Source: Brain Tumor Pathology)
Source: Brain Tumor Pathology - August 25, 2018 Category: Neurology Source Type: research
Anaplastic changes of diffuse leptomeningeal glioneuronal tumor with polar spongioblastoma pattern
AbstractDiffuse leptomeningeal glioneuronal tumor (DLGNT) is a rare glioneuronal neoplasm with oligodendroglioma-like cells confined in the subarachnoid spaces. A great majority of DLGNT are histologically low grade. However, some tumors show features of anaplasia with increased mitotic and proliferative activity. Due to the limited number of patients and inadequate clinical follow-up reported to date, the WHO classification does not yet assign a distinct WHO grade to this entity. Polar spongioblastoma pattern, in which bipolar cells are arranged in parallel with palisading nuclei, remains poorly understood about the patho...
Source: Brain Tumor Pathology - July 26, 2018 Category: Neurology Source Type: research
