Glioneuronal and neuronal tumors: A review with special reference to the new types in the WHO CNS5 classification

Glioneuronal and neuronal tumors (GNTs) are slow-growing lower-grade neuroepithelial tumors with mature neuronal and, less consistently, glial differentiation. Their identification has relied solely on histological proof of neuronal differentiation, which was considered to represent the well-differentiated nature of GNTs. However, after discovering the genetic alterations in GNTs, particularly those in the MAP-kinase pathway, it became evident that histological diagnoses are not always concurrent with genetic alterations and vice versa. Furthermore, since several inhibitors mediating the MAP-kinase pathway are available, at least for clinical trials, molecular-based classification is now warranted. Thus, the upcoming WHO Classification of Central Nervous System Tumors, 5^th edition (WHO5CNS) applied DNA methylation profiling to segregate low-grade neuroepithelial tumors. This review gives an overview of the pathological features of GNTs with particular reference to the newly listed tumor types in WHO5CNS. The knowledge and awareness of each tumor type are essential to make a correct diagnosis and avoid unnecessary radical resection and chemoradiotherapy, as GNTs are relatively indolent and have a prolonged clinical course. In addition, being distinctive in location, age group, and histology, the integration of clinicopathological information will help identify relevant tumor types of GNTs without genetic testing, even in resource-limited settings.

Cerebral astroblastoma with oligodendroglial-like cells: A case report

RATIONALE

Astroblastoma is a rare tumor of the central nervous system with uncertain biological behavior and origin. Its histopathological features have been well established, while, to our knowledge, astroblastoma with oligodendroglial-like cells have not been reported.

PATIENT CONCERNS

A 15-year-old girl presented with nausea, vomiting, headache, and visual disturbance.

DIAGNOSIS

Magnetic resonance imaging revealed a large neoplasm in the left temporal. Histologically, the tumor showed solid and pseudopapillary structure. Immunohistochemical staining showed that the tumor cells were positive for glial fibrillary acidic protein and vimentin. The oligodendroglial-like cells were positive for glial fibrillary acidic protein, vimentin, and oligodendrocyte transcription factor 2. The antigen KI67 labeling index was about 4%. Sequencing for isocitrate dehydrogenase (IDH) 1 codon 132 and IDH2 codon 172 gene mutations showed negative results. Furthermore, fluorescent analysis revealed neither 1p nor 19q deletion in the lesion. Based on these findings, the girl was finally diagnosed as astroblastoma.

INTERVENTIONS

A craniotomy with total excision of the tumor was performed.

OUTCOMES

The follow-up time was 1 year, no evidence of disease recurrence was found in magnetic resonance imaging.

LESSONS

Cerebral astroblastoma with oligodendroglial-like cells is a clinically rare tumor of central nervous system. Clear distinction and diagnosis are critical.

Surgical and Seizure Treatment Outcomes in Adult Dysembryoplastic Neuroepithelial Tumors: a Case Series

Dysembryoplastic neuroepithelial tumors (DNETs) are benign neoplasms classified in the category of glioneuronal tumors. The estimated incidence of DNETs is 0.03 per 100,000 person per year with the age peak in a range between 10 and 14 years, and decreasing dramatically with increasing age. They are seldom diagnosed in persons above 20 years of age, being a cause of tumor-related intractable epilepsy that begins in childhood or adolescence. They have been proven to be the second most common type of epileptogenic tumors in pediatric population. These rare tumors cause chronic drug-resistant partial complex seizures with or without secondary generalization. Herein, we provide institutional case series of six adult patients with temporal lobe DNET presenting with complex partial seizures. Lesionectomy was performed with tumor resection in toto in three patients. In another three, partial resection was performed, whereas tumor remnant was left intact to avoid possible basal ganglia damage. All patients were seizure free postoperatively. Lesionectomy alone in temporal lobe epilepsy was associated with less favorable outcome than anterior temporal lobectomy. Total tumor removal is considered a major prognostic factor in most studies.

Dysembryoplastic Neuroepithelial Tumors: What You Need to Know

OBJECTIVE

An updated and comprehensive review on dysembryoplastic neuroepithelial tumor (DNET) focusing on differential diagnosis, atypical presentation, seizure outcome, and risk of malignant transformation.

METHODS

A PubMed/MEDLINE-based literature search has been performed using "dysembryoplastic neuroepithelial tumor" as a keyword. Two treated cases characterized by an atypical presentation have been reviewed.

RESULTS

Of 1162 articles, 200 relevant studies have been selected. DNET is a benign mixed neuronal-glial tumor causing drug-resistant epilepsy primarily in children and young adults. The typical radiological pattern is a magnetic resonance imaging (MRI) T1-hypointense, T2-, and fluid-attenuated inversion-recovery hyperintense multicystic lesion involving the cerebral cortex with no edema. Contrast enhancement may be present and a focal cortical dysplasia is commonly associated with it. MRI diffusion, perfusion, and spectroscopy have a paramount role in the differential diagnosis. The "specific glioneuronal elements" are pathognomonic. They are positive for S100 protein, synaptofisin, neuronal nuclei, oligodendrocyte transcription factor, neurite outgrowth inhibitor, and microtubule-associated protein 2, but negative for glial fibrillary acidic protein. As opposed to v-myb avian myeloblastosis viral oncogene homolog, isocitrate dehydrogenase-1/isocitrate dehydrogenase-2 mutation and codeletion 1p-19q, fibroblast growth factor receptor 1 and BRAF V600E mutations are present. The effectiveness of surgery on seizure outcome has been established. Rare malignant transformations have been reported, especially in extra-temporal and complex forms.

CONCLUSIONS

Advanced MRI techniques are fundamental in the differential diagnosis for DNET versus other low-grade gliomas. Immuno-phenotype assessment and search for fibroblast growth factor receptor 1 and BRAF V600E mutations limit the risk of misdiagnoses. A gross total tumor removal is generally associated with a seizure-free outcome. Recurrences and malignant transformations may rarely follow, legitimizing MRI surveillance in cases of subtotal tumor resection.

Gliomatosis cerebri: a consensus summary report from the Second International Gliomatosis cerebri Group Meeting, June 22-23, 2017, Bethesda, USA

Gliomatosis cerebri (GC) is an aggressive glioma characterized by an invasive growth pattern and a dismal prognosis. The low incidence and non-specific symptoms at presentation pose unique challenges for early diagnosis and disease-specific research. There is no standard of care for the treatment of patients with a GC phenotype. Understanding the biology of this entity is a critical step in determining effective treatments. Toward this end, the Second International GC Group convened at National Institutes of Health, Bethesda on June 22nd-23rd 2017. This paper summarizes the main conclusions and recommendations for research priorities to fight this fatal condition.

Dysembryoplastic neuroepithelial tumor-like pilocytic astrocytoma: A case report

RATIONALE

Pilocytic astrocytoma (PA) typically shows biphasic pattern with a mixture of loose microcystic and compact regions, in which it is not uncommon to see heterogeneous morphology. However, there has not been reported in the literatures of the PA type that shows similarity to dysembryoplastic neuroepithelial tumor (DNT) in both histological morphology and immunophenotype.

PATIENT CONCERNS

The present study described a case of PA affecting the right temporal-occipital lobe in a 22-year-old male patient. Morphologically, it composed of totally distinctive microcystic pattern. The classical biphasic pattern of PA was not observed. Immunohistochemically, neuronal marker NeuN was expressed in tumor cells scattered in the background which simulated its expression morphology in DNT. However, KIAA1549-BRAF fusion gene was identified by fluorescence in situ hybridization (FISH), supporting for the diagnosis of PA.

DIAGNOSES

DNT-like PA (WHO grade I).

INTERVENTIONS

The tumor was totally removed via a right temporal-occipital craniotomy.

OUTCOMES

The patient is free of local recurrence and dissemination eleven months after surgical resection of the lesion.

LESSONS

We herein report a rare case of DNT-like PA. For diagnosis, KIAA1549-BRAF fusion gene should be detected under similar situation.

[Clinicopathologic features of infant dysembryoplastic neuroepithelial tumor: a case report and literature review]

Dysembryoplastic neuroepithelial tumor (DNT) has traditionally been viewed as rare benign tumors that present with seizure widely considered curable with surgery alone. Most DNTs occur in childhood and young adults. However, rare reported cases occur in infants. This paper reported an infant case of DNT and its diagnosis, differential diagnosis, treatment, molecular features and prognosis based on the review of current literatures. The age onset of this patient was only 11 months old. The clinical manifestations were partial seizures and the imaging data untypical; CT and MRI were all supportive of astrocytoma. Typical glioneuronal element histologic features could be seen, which contained oligodendrocyte-like cells attached to bundles of axons and neurons floating in a myxoid interstitial fluid. Meanwhile, some atypical regions could also be seen. These atypical regions showed a mixture of oligodendrocyte-like cells and neurons without a myxoid interstitial fluid, which were easily misdiagnosed. The BRAF^V600E mutation was not detected. This patient had a good response to drug therapy. Totally surgical resection of the tumor was conducted. The patient had been seizures free for 6 months. In conclusion, DNT is a rare and well prognostic tumor (WHO grade I), which most often arise in children in the setting of medically refractory epilepsy. The most common tumor location was temporal. Because clinical symptoms, imaging and histological features of DNT and other low-grade gliomas broadly overlap such as ganglioglioma, pilocytic astrocytomas and oligodendroglioma et al., differential diagnosis should be made carefully. The glioneuronal element was the histopathological hallmark of DNT. In addition, some untypical regions should also be called attention. Although BRAF^V600E mutation didn't exist in this case, it played a role in differential diagnosis because it has been previously recorded that BRAF^V600E mutation was a common feature of DNT. Infant patients have their own characteristics. For example, drug therapy worked well and the imaging data was untypical. Doctors should improve the understanding of this disease to avoid unnecessary radiotherapy or chemotherapy.

Low-grade Glial Tumor with Features of Astroblastoma in a Dog

A 12-year-old, neutered, male Belgian Malinois/Great Dane cross dog presented with a 5-month history of weakness and lack of endurance followed by acute onset of rear limb ataxia. At autopsy, a 9 x 16 mm, multilobular, firm, white to tan, expansile mass was found in the cerebellum. Mild dilatation of the lateral ventricles was also noted. Histologically, there was a well-demarcated glial neoplasm composed of medium-sized astrocytic elements that had homogeneous cytoplasm, sometimes with globular eosinophilic inclusions, irregular peripherally located nuclei with a single nucleolus, and short cytoplasmic processes. Prominent peri-vascular pseudorosettes with cellular processes in contact with blood vessels were present. Some blood vessels exhibited hyalinized walls. Mitotic figures were not observed. Immunohistochemically, neoplastic cells expressed glial fibrillary acidic protein and vimentin. These features are consistent with an astroblastoma. This is the first clinicopathologic correlation and detailed description of a low-grade glial tumor with features of astroblastoma in a dog.

Rapid immunocytochemistry based on alternating current electric field using squash smear preparation of central nervous system tumors

The role of intraoperative pathological diagnosis for central nervous system (CNS) tumors is crucial for neurosurgery when determining the surgical procedure. Especially, treatment of carmustine (BCNU) wafers requires a conclusive diagnosis of high-grade glioma proven by intraoperative diagnosis. Recently, we demonstrated the usefulness of rapid immunohistochemistry (R-IHC) that facilitates antigen-antibody reaction under alternative current (AC) electric field in the intraoperative diagnosis of CNS tumors; however, a higher proportion of water and lipid in the brain parenchyma sometimes leads to freezing artifacts, resulting in poor quality of frozen sections. On the other hand, squash smear preparation of CNS tumors for cytology does not affect the frozen artifacts, and the importance of smear preparation is now being re-recognized as being better than that of the tissue sections. In this study, we established the rapid immunocytochemistry (R-ICC) protocol for squash smears of CNS tumors using AC electric field that takes only 22 min, and demonstrated its usefulness for semi-quantitative Ki-67/MIB-1 labeling index and CD 20 by R-ICC for intraoperative diagnosis. R-ICC by AC electric field may become a substantial tool for compensating R-IHC and will be applied for broad antibodies in the future.

Intraventricular Astroblastoma in an Infant: A Case Report and Review of the Literature

Astroblastomas are rare intracranial tumours of uncertain origin and are commonly present in the supratentorial compartment. Astroblastomas often affect children and young adults. Their occurrence in an intraventricular location, in an infant, is extremely uncommon. We describe a 1-year-old boy who presented with features of raised intracranial pressure. An MRI scan revealed an intralateral ventricular tumour. Complete excision was performed. Its histopathological examination revealed features consistent with astroblastoma. A follow-up MRI scan after 9 months did not show any residual tumour, and the patient was followed up without any adjuvant therapy. The radiological and histopathological characteristics of this tumour are described in our report.

An individual patient data meta-analysis on characteristics and outcome of patients with papillary glioneuronal tumor, rosette glioneuronal tumor with neuropil-like islands and rosette forming glioneuronal tumor of the fourth ventricle

Background and Purpose

In 2007, the WHO classification of brain tumors was extended by three new entities of glioneuronal tumors: papillary glioneuronal tumor (PGNT), rosette-forming glioneuronal tumor of the fourth ventricle (RGNT) and glioneuronal tumor with neuropil-like islands (GNTNI). Focusing on clinical characteristics and outcome, the authors performed a comprehensive individual patient data (IPD) meta-analysis of the cases reported in literature until December 2012.

Methods

PubMed, Embase and Web of Science were searched for peer-reviewed articles reporting on PGNT, RGNT, and GNTNI using predefined keywords.

Results

95 publications reported on 182 patients (PGNT, 71; GNTNI, 26; RGNT, 85). Median age at diagnosis was 23 years (range 4–75) for PGNT, 27 years (range 6–79) for RGNT, and 40 years (range 2–65) for GNTNI. Ninety-seven percent of PGNT and 69% of GNTNI were located in the supratentorial region, 23% of GNTNI were in the spinal cord, and 80% of RGNT were localized in the posterior fossa. Complete resection was reported in 52 PGNT (73%), 36 RGNT (42%), and 7 GNTNI (27%) patients. Eight PGNT, 3 RGNT, and 12 GNTNI patients were treated with chemo- and/or radiotherapy as the primary postoperative treatment. Follow-up data were available for 132 cases. After a median follow-up time of 1.5 years (range 0.2–25) across all patients, 1.5-year progression-free survival rates were 52±12% for GNTNI, 86±5% for PGNT, and 100% for RGNT. The 1.5-year overall-survival were 95±5%, 98±2%, and 100%, respectively.

Conclusions

The clinical understanding of the three new entities of glioneuronal tumors, PGNT, RGNT and GNTNI, is currently emerging. The present meta-analysis will hopefully contribute to a delineation of their diagnostic, therapeutic, and prognostic profiles. However, the available data do not provide a solid basis to define the optimum treatment approach. Hence, a central register should be established.

Case of primary diffuse leptomeningeal gliomatosis

Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare and fatal disease characterized by diffuse infiltration of the leptomeninges by neoplastic glial cells without evidence of tumor in the brain parenchyma or spinal cord. We report a 60-year-old man with PDLG. He suffered transient right hemiparesis and generalized seizures. MRI showed diffuse leptomeningeal thickening and enhancement throughout the brain and spinal cord without any intraaxial involvement. Biopsy resulted in a diagnosis of glioblastoma with methylated MGMT promoter and wild-type IDH1. He underwent craniospinal radiotherapy and temozolomide treatment but despite concomitant adjuvant therapy he died 8 months after initial presentation.

[Leptomeningeal gliomatosis with high levels of adenosine deaminase in the cerebrospinal fluid]

A 61-year-old man developed disturbance of consciousness for 2 weeks. He showed neck stiffness and hyporeflexia. Analysis of his cerebrospinal fluid (CSF) revealed pleocytosis and markedly reduced glucose contents. Adenosine deaminase (ADA) levels in the CSF were elevated (28.8 IU/l). Brain magnetic resonance imagings showed enhancement of the leptomeninges. Tuberculous meningitis was considered, but antituberculous drug was not effective. Repeated cytological analysis of the CSF demonstrated atypical cells with enlarged unevenly distributed nuclei and immunoreactive with glial fibrillary acidic protein. We diagnosed him as leptomeningeal gliomatosis. CSF ADA may be elevated in this rare disorder, and here we emphasize that repeated cytological analysis with immunohistochemical staining was useful for diagnosis.

Dysembryoplastic neuroepithelial tumor with atypical presentation: MRI and diffusion tensor characteristics

We report the neuroimaging findings of a 26-year-old female patient with a biopsy-proven dysembryoplastic neuroepithelial tumor (DNET). DNETs are an uncommon, usually benign, glial-neural cortical neoplasm of children and young adults who typically present with intractable seizures. DNETs may occur in any region of the supratentorial cortex, but have a predilection for the temporal lobes. Accurate neuroimaging diagnosis is essential since patients with DNET benefit from complete resection. However, accurate differentiation from other cortical lesions may be challenging. Typical conventional Magnetic Resonance Imaging (MRI) features can help in the differentiation from other similar cortical tumors. Diffusion tensor imaging can also provide important additional diagnostic information regarding the degree of involvement of adjacent parenchyma and white matter tracts. In this case, tractography and fractional anisotropy maps demonstrated that fiber tracts surrounding the lesion were displaced, but fiber integrity was maintained, which is more suggestive of a DNET rather than a more aggressive neoplasm. Accurate identification of DNETs is essential for the purpose of rendering a timely diagnosis and start appropriate treatment.

[Differential diagnosis of and therapy for anaplastic astroblastoma: case report and review of the literature]

Astroblastomas are rare glial tumors. We report a case of 33-year-old woman with high-grade astroblastoma with hypervascularity. She had a one-month history of right visual disturbance and papillar edema. MRI revealed a lobulated mass with cysts and flow voids in the right superficial frontal lobe, a phenomenon described as "bubbly appearance". Right carotid angiography demonstrated marked tumor stain and early venous filling. MR spectroscopy showed an increase in myoinositol and the choline/creatine ratio, and decreased N-acetyl aspartate. The lipid and lactate level was not increased. The well-circumscribed tumor was totally resected. Histological examination showed perivascular pseudorosettes and hyalinization of blood vessels with high cellularity, anaplastic nuclear features, focal necrosis, mitosis, and endothelial proliferation. Immunohistochemically, glial fibrillary acidic protein and S-100 protein were intensely positive and the MIB-1 labeling index was high(20%)in the tumor cells. Based on these findings, a diagnosis of high-grade astroblastoma was made. The patient received postoperative radiotherapy and chemotherapy with temozolomide and suffered no relapse in the course of 3 years after surgery. Characteristically, astroblastomas manifest a "bubbly appearance" and a lobulated mass on MRI scans. As these tumors tend to be hypervascular, angiograms are useful for designing the operative strategy. However, their low-or high grade is difficult to ascertain preoperatively based on MRI-, MRS-, and DSA findings. The standard therapy for high-grade astroblastoma is total resection and postoperative radiation therapy. As the incidence of tumor recurrence is high, we recommend additional chemotherapy with TMZ.

[Subependymoma of the lateral ventricle. A case report]

INTRODUCTION. Intracranial subependymomas are rare, slow-growing, noninvasive, benign tumors. They are most often located in the fourth ventricle. Most of these tumors are discovered incidentally during autopsy. Routine medical checkups using neuroimaging techniques have increased their diagnosis. Subependymomas may present with symptoms related to cerebrospinal fluid obstruction or mass effect. CASE REPORT. A 52-year-old man presented with severe headache and mental deterioration with memory disturbances and bradypsychia. Computed tomography and magnetic resonance imaging revealed a mass in the right lateral ventricle causing obstructive hydrocephalus. The tumour was totally removed through a right frontal transcortical approach. Histological examination showed a typical subependymoma. A complete neurological recovery was achieved after surgery. CONCLUSIONS. Subependymomas are rare low-grade glial neoplasm that commonly arise in the ventricular system. They have a low-proliferative potential but in these locations they can cause symptomatic hydrocephalus. Surgical removal of the mass and the restoration of the normal cerebrospinal fluid pathways constitute the optimal management strategy.

[Cryodestruction in neurosurgery]

The study aimed to work out the method of cryodestruction of brain tumors. 10 patients with neuroepithelial brain tumors were prospectively operated on with the use of cryodestruction. MRI was performed before and after the operation. The operation strated from tumor biopsy under the ultrasound control with further injection of cryoprobe with further destruction. The study demonstrated that ultrasound navigation is an effective means of the cryodestruction control on all stages. The cryodestruction itself is a miniinvasive, easily controlled and effective method, applicable for tumors, located in functionally important regions of the brain, where major surgery could be mutilating.

[Response to treatment with corticoids in a case of inflammatory amyloid angiopathy without performing a biopsy]

INTRODUCTION

Inflammatory amyloid angiopathy (IAA) is an infrequent presenting symptom of the recently recognised cerebral amyloid angiopathy and its definitive diagnosis is reached by means of pathological analyses.

AIM

We report the case of a male patient with IAA and good clinical, neuropsychological and neuroimaging response to treatment with corticoids; a biopsy of brain tissue was not considered necessary.

CASE REPORT

The patient, 68 years old and diagnosed with Alzheimer's disease, suffered from generalised seizures followed by a language disorder and hemiparesis of the right-hand side. A magnetic resonance imaging scan showed a lesion displaying infiltrating behaviour in the left hemisphere and multiple instances of microbleeding. Clinical and radiological features suggested IAA and treatment was established with corticoids. Neuroimaging and neuropsychological tests revealed a notable improvement at 30 days after beginning treatment with immunosuppressants. The genotype was ApoE e4/e4. The need to perform a biopsy of brain tissue was ruled out.

CONCLUSIONS

The case described here suggests that, in individualised cases with clinical and radiological features that are characteristic of IAA, it may be possible to establish an empirical treatment with corticoids with a probability diagnosis and perform a biopsy of brain tissue in the event of a lack of response to treatment.

[Identification of highly specific electroencephalographic patterns in patients with neuroepithelial tumors of the III ventricle by algorithmic methods]

An algorithm was suggested for identifying highly specific electroencephalographic (EEG) patterns in neurooncologic patients. The algorithm provides selection of patients with their further classification into main and control groups based on the already existing database of EEG indicators; requests to it; generation of mono-indicator candidates for EEG-patterns on the basis of a 4-dipole table for selecting and verifying sensitive and specific EEG patterns and outlining the best ones. Our material included 368 patients with basal-diencephalic tumors. Algorithmic methods revealed new EEG patterns in patients with different anatomical and topographical variants of neuroepithelial tumors in the III ventricle. We think it reasonable to use the revealed syndromes to improve diagnosis and identify pathophysiological basis of clinical syndromes.

Anaplastic astroblastoma: a rare glial tumour

Astroblastoma is a rarely diagnosed primary brain neoplasm whose histogenesis has been clarified recently. It occurs in children and young adults and presents as a well-circumscribed, contrast enhancing lesion in the cerebral hemisphere. Here the authors present a case of 25-year-old woman with an astroblastoma in the left frontal convexity that was excised. The characteristic radiological and histopathological features of this case are described. An astroblastoma should be included in the differential of a localised brain tumour, especially in a young patient.

[Multiple intracranial lesions: a clinicalpathologic study of 62 cases]

OBJECTIVE

To study the clinicalpathologic features of intracranial multiple lesions.

METHODS

The clinical, radiologic and pathologic features of intracranial multiple lesions in 62 cases during the period from 2005 to 2009 in Xuanwu Hospital were retrospectively reviewed.

RESULTS

There were 32 males and 30 females in 62 cases. The mean age of seize onset and duration of disease were 37.4-year-old and 11.6 months, respectively. The lesions could affect cerebral hemisphere, basal ganglia, brain stem, cerebellum and other parts, most lesions were located above the tentorium. Pathological diagnosis as follows: 13 patients with glioma; metastatic tumors in 13 cases; 12 cases of central nervous system infection; immune-mediated inflammatory demyelinating disease in 8 cases; 5 cases of primary lymphoma of central nervous system; primary angiitis of the central nervous system 3 cases; mitochondrial encephalopathy 2 cases; vein thrombosis in 2 cases; Rosai-Dorfman disease in 2 cases; 2 case of radiation encephalopathy. Among them, mitochondrial encephalopathy and vein thrombosis lesions located in the cortex; metastatic tumor and blood-borne infection mainly involving junction of grey and white matter; glioma, radiation encephalopathy and demyelinating disease include white matter lesions; vascular inflammation showed cortical and subcortical white matter lesions.

CONCLUSIONS

A variety of tumor and non-neoplastic diseases can be expressed in intracranial multiple lesions, which gliomas, metastatic tumor and central nervous system infections are more common. In order to improve the diagnosis of intracranial multiple lesions, active work in the brian biopsy, study the clinical, imaging and pathological findings must be closely.

[A case of primary diffuse leptomeningeal gliomatosis, clinically indistinguishable from metastatic meningeal carcinomatosis]

A 65-year-old woman presented with progressive gait disturbance. She complained of appetite loss for 3 months. Her gait gradually became unsteady, and she was admitted to our hospital. On admission, slow mentation, bathyhypesthesia in left upper and both lower extremites, positive Romberg sign and wide-based gait were observed. Gd-enhanced MRI revealed mass lesions in the left temporal fossa and the cervical spinal canal with focal meningeal enhancement. Besides lesions in the central nervous system (CNS), systematic examination detected no additional malignancy. Repeated cytology of the cerebrospinal fluid was negative. After admission, her consciousness became reduced gradually. At 2 months after admission, she died of central respiratory failure. On autopsy, diffuse extension of the tumor cells was observed on the surface of CNS, and the mass lesions observed by MRI were extra-parenchymal On microscopic examination, the mass was consisted of GFAP positive malignant cells, and included perivascular pseudorosette, pseudopalisading necrosis and many mitotic cells. The diagnosis of the case was made as primary diffuse leptomeningeal gliomatosis (PDLG). PDLG is a rare disorder that is difficult to diagnose by CSF cytology. The progress of PDLG is rapid, and appropriate treatment is rarely taken. However, the combination of temozolomide and the radiotherapy performed for a glioblastoma has been reported as a possible treatment for PDLG. We emphasize that, in possible cases of PDLG, a biopsy should be performed in the early stages, especially in cases showing features similar to those of metastatic meningeal carcinomatosis and have no malignant tumors by whole body examination.

[Algorithm identification of differential diagnostic clinical syndromes in patients with neuroepithelial tumors of the III ventricle]

An algorithm for identifying differential diagnostic clinical syndromes in neurooncologic patients was suggested. This technique involves: creating a database of cases - lists of symptoms, requests for selection of thematic cases with their subsequent division into the main and control groups; generation of single-symptom applicants; selection and verification of clinical differential diagnostic syndromes appropriate to sensitivity and specificity using a 4-dipole table and selection of the best of them. Based on the database of 368 patients with tumors of basal-diencephalic localization, we tried to perform the algorithm of identification of differential diagnostic clinical syndromes in patients with different anatomical and topographical variations of neuroepithelial tumors of the III ventricle. The identified syndromes are reasonable to use for selecting the optimal treatment strategy.

GLUT1 expression in malignant tumors and its use as an immunodiagnostic marker

OBJECTIVE

To analyze glucose transporter 1 expression patterns in malignant tumors of various cell types and evaluate their diagnostic value by immunohistochemistry.

INTRODUCTION

Glucose is the major source of energy for cells, and glucose transporter 1 is the most common glucose transporter in humans. Glucose transporter 1 is aberrantly expressed in several tumor types. Studies have implicated glucose transporter 1 expression as a prognostic and diagnostic marker in tumors, primarily in conjunction with positron emission tomography scan data.

METHODS

Immunohistochemistry for glucose transporter 1 was performed in tissue microarray slides, comprising 1955 samples of malignant neoplasm from different cell types.

RESULTS

Sarcomas, lymphomas, melanomas and hepatoblastomas did not express glucose transporter 1. Forty-seven per cent of prostate adenocarcinomas were positive, as were 29% of thyroid, 10% of gastric and 5% of breast adenocarcinomas. Thirty-six per cent of squamous cell carcinomas of the head and neck were positive, as were 42% of uterine cervix squamous cell carcinomas. Glioblastomas and retinoblastomas showed membranous glucose transporter 1 staining in 18.6% and 9.4% of all cases, respectively. Squamous cell carcinomas displayed membranous expression, whereas adenocarcinomas showed cytoplasmic glucose transporter 1 expression.

CONCLUSION

Glucose transporter 1 showed variable expression in various tumor types. Its absence in sarcomas, melanomas, hepatoblastomas and lymphomas suggests that other glucose transporters mediate the glycolytic pathway in these tumors. The data suggest that glucose transporter 1 is a valuable immunohistochemical marker that can be used to identify patients for evaluation by positron emission tomography scan. The function of cytoplasmic glucose transporter 1 in adenocarcinomas must be further examined.

A case of gliomatosis cerebri mimicking limbic encephalitis: malignant transformation to glioblastoma

Gliomatosis cerebri (GC) is a specific entity defined as diffuse infiltration of neoplastic glial cells into at least three cerebral lobes and preservation of the surrounding neuronal architecture. We report a patient with secondary GC that mimicked clinicoradiological features of limbic encephalitis (LE). A 72-year-old man had developed headache and disorientation insidiously 2 weeks previously. On admission, neurological examination showed confusion and hyperreflexia in the right extremities. Brain magnetic resonance imaging (MRI) revealed T2-hyperintensity in bilateral frontal, the left parietal, the left temporal lobes and bilateral posterior periventricular zones. Slight enhancement existed in the left lower temporal region. Cerebral angiography exhibited no tumor stains. Repeated cerebrospinal fluid studies showed mild pleocytosis and cytology of class I. There were no infectious pathogenic agents. His neurological symptoms were ameliorated at 7 days after treatment with dexamethasone and glycerol. Follow-up MRI showed no pathognomonic changes. Mild memory dysfunction remained. He was diagnosed as LE of unknown cause. Three months later he became disorientated. Brain CT revealed a hemorrhagic mass with surrounding edema in the left temporal, frontal and parietal lobes. MRI displayed marked enhancement in these regions. Urgent neurosurgery was performed and glioblastoma multiforme (GM) was confirmed pathologically. The early clinicoradiological course of this patient suggested similarities to LE. At 3 months after clinical onset, the neuroradiological features reflected rapid transformation from secondary GC to massive GM. Thus, it is important to pay more attention to the differential diagnoses of GC and LE in patients who have memory deficits and widespread MRI lesions.

Gliomatosis cerebri mimicking chemotherapy-induced leukoencephalopathy in a patient with non-Hodgkin's lymphoma

Patients with hematological malignancies may develop white matter lesions, which are usually associated with chemotherapy. Magnetic resonance imaging (MRI) is the imaging modality of choice for identifying chemotherapy-induced, or "toxic", leukoencephalopathy. Brain biopsy in patients with hematological malignancies suspected of sustaining toxic leukoencephalopathy has rarely been performed, because its characteristic MRI findings are considered pathognomotic. Biopsy may be indicated in atypical cases, however, and it may yield unexpected results. We describe a case with white matter lesions that developed in an elderly man treated for non-Hodgkin's lymphoma. The lesions, initially diagnosed with toxic leukoencephalopathy based on MRI findings, turned out to be gliomatosis cerebri.

Gliomatosis cerebri

Gliomatosis cerebri is a rare diffusely infiltrating glial tumor involving two or more lobes and is frequently is bilateral. Infiltrative extent of tumor is out of proportion to histological and clinical features. We present a case in which finally the diagnosis of gliomatosis cerebri was made. In this case, computed tomography showed that midline structures were insignificantly shifted to the left, there was a mild dilatation of lateral ventricles more expressed on the right, and no pathologic changes of brain tissue density were found. On magnetic resonance tomography, T2W/SE and T2W/FLAIR images revealed zones of hyperintense signal, spreading with time, through several lobes of the brain with no enhancement on T1W images. Diagnosis of gliomatosis cerebri was suspected, stereotaxic biopsy was performed, and pathological examination revealed changes typical of diffuse glial tumor. In this article, changes typical of gliomatosis cerebri seen in other radiological methods such as computed tomography, magnetic resonance spectroscopy, dynamic contrast-enhanced T2*-weighted magnetic resonance, and positron emission tomography also are discussed.

Utility of functional diffusion maps to monitor a patient diagnosed with gliomatosis cerebri

Diffusion-weighted magnetic resonance imaging (DWI) is a sensitive imaging biomarker for tumor cellularity. Functional diffusion maps (fDMs), which examine voxel-by-voxel changes in the apparent diffusion coefficient (ADC) calculated from serial DWIs, have previously been applied to regions of contrast-enhancement; however, application of fDMs to non-enhancing brain tumors has not been pursued. In this case study we demonstrate the utility of applying fDMs to regions of abnormal FLAIR signal intensity in a patient diagnosed with gliomatosis cerebri: a relatively rare, infiltrative, non-enhancing brain tumor. The absolute volume of hypercellularity extracted from fDMs was useful in tracking tumor growth, which correlated in time with a progressive decline in neurological status despite no change in traditional magnetic resonance images. Results of this study demonstrate the value of fDMs, applied to regions of FLAIR abnormal signal intensity, for localizing regions of hypercellularity and for monitoring overall tumor status.

Dysembryoplastic neuroepithelial tumors in pediatric patients

OBJECTIVE

Dysembryoplastic neuroepithelial tumors (DNTs) are benign cortical tumors that are frequently associated with the medically intractable focal epilepsy. In this study, the authors delineate the clinical characteristics of DNTs in children and evaluate the role of cortical dysplasia (CD) in the epileptogenicity to find out the optimum surgical strategy.

METHODS

A retrospective analysis was performed for clinical data of children with DNT, who underwent surgery between 1996 and 2006. The adopted surgical methods were uniform according to the tumor location and included intraoperative electrocorticography (ECoG)-guided resection. The prognostic factors were evaluated for the two prognostic group categorized by the seizure outcome at one year after surgery.

RESULTS

Of 22 patients, the overall seizure free rate was 90.9% and the other two patients belonged to Engel class II during the mean follow-up period of 44.1 months. There was no worsening of the seizure after one year of surgery. Associated CD was found in 18 cases (81.8%) and in the 80% (8 of 10 cases) of the additionally resected areas according to the electrophysiologic studies.

CONCLUSIONS

The CD associated with DNT appears to have its own epileptogenicity. Therefore, complete removal of the CD with tumor itself is important for patient outcome. A thorough surgical approach can be accomplished by comprehensive presurgical evaluations and extensive surgery with the aid of the intraoperative ECoG or intracranial recording.

VISUALIZING NEURONAL STRUCTURES IN THE HUMAN BRAIN VIA DIFFUSION TENSOR MRI

Acquisition, analysis, and visualization of diffusion tensor magnetic resonance imaging (DT-MRI) is still an evolving technology. This article reviews the fundamentals of the data acquisition process and the pipeline leading to visual results that are interpretable by physicians in their clinical practice. The limitations of common approaches for visualizing the retrieved data are discussed and a new statistical method is presented to assess the reliability of the acquired tensor field. A novel visualization method is proposed which is discussed in light of neurophysiological considerations of the perception of colored patterns. It is argued that this method is more accurate for medical data while providing a nearly optimal visual stimulus. The method is evaluated on a patient study with a brain tumor.

Pseudo-subarachnoid hemorrhage and cortical visual impairment as the presenting sign of gliomatosis cerebri

A 49-year-old white male presented with a pseudo-subarachnoid hemorrhage and diffuse brain edema. Neuroimaging showed brain edema causing the unusual findings of a pseudo-subarachnoid hemorrhage and bilateral occipital lobe infarcts following herniation and compression of the posterior cerebral arteries. An enlarged corpus callosum was noted which led to a brain biopsy and a diagnosis of gliomatosis cerebri.

A history of partial complex seizures in a 30-year-old woman

Dysembryoplastic neuroepithelial tumour is an uncommon lesion of the brain characterised by a heterogeneous population of neurons, astrocytes and oligodendroglia-like cells. Most patients are young adults with a long history of drug-resistant seizures. We report a case of a 31 year-old woman with a history of severe epileptic attacks. Cerebral imaging showed a left temporal tumour measuring 4 cm in its greater dimension. After surgical intervention, histopathological examination showed a tumoural proliferation with both glial and neuronal components that was confirmed by immunohistochemistry. We also describe the spectrum of dysembryoplastic neuroepithelial tumours and their histological features.

[Glioblastoma multiforme developing separately from the initial lesion 9 years after successful treatment for gliomatosis cerebri: a case report]

Gliomatosis cerebri is a diffuse growth pattern of glioma consisting of exceptionally extensive infiltration of at least three cerebral lobes. We report a case of histologically confirmed glioblastoma multiforme in the cerebellar vermis which occurred 9 years after treatment for gliomatosis cerebri. A 33-year-old woman presented to our department for evaluation of visual disturbance. T2-weighted magnetic resonance (MR) imaging revealed hyperintense lesions in the bilateral frontal and parietal lobes. Histological examination of biopsy specimens from the left frontal lobe lesion demonstrated diffuse infiltration of glial neoplastic cells with preservation of the underlying cytoarchitecture, leading to the diagnosis of gliomatosis cerebri. She received 60 Gy hyperfractionated irradiation to the whole brain, and the lesion responded partially. The patient remained stable for 4 years, but T2-weighted MR imaging 5 years after the initial treatment showed enlargement of the hyperintense area. She received nimustine hydrochloride chemotherapy, and again partial response was observed. However. T1-weighted MR imaging after administration of gadolinium-diethylenetriaminepenta-acetic acid detected enhanced lesions in the cerebellar vermis, cerebellar hemisphere, and left posterior limb of the internal capsule 9 years after the initial treatment, although no abnormal findings were observed on initial and follow-up MR imaging. She underwent subtotal removal of the lesion in the cerebellar vermis. The surgical specimens were characterized by dense proliferation of atypical tumor cells with scattered mitosis and endothelial proliferation. The histological diagnosis was glioblastoma multiforme. The patient received gamma knife irradiation for the remnant lesion in the cerebellar vermis, and the lesions in the cerebellar hemisphere and left posterior limb of the internal capsule, and chemotherapy with temozolomide. However, multiple enhanced lesions were detected in the cerebellar vermis 2 months after the start of the temozolomide chemotherapy, and she died 8 months later. This case suggests that glioblastoma multiforme could develop in the long term after initial treatment for gliomatosis cerebri, and in a location separate from the initial lesion.

Uncontrolled headache induced by oxcarbazepine

Headache induced by acute exposure to a specific drug constitutes an idiosyncratic side effect. Metabolic imbalance appears as the leading aetiology, among several other hypotheses. Either primary headaches show a higher susceptibility to this idiosyncratic reaction or a drug-induced primary headache evolves in intensity and duration, becoming uncontrolled until the complete discontinuation of the drug in consideration. The goal of this study is to describe three patients diagnosed with migraine and epilepsy (both under control) who evolved into status migrainosus after the introduction of oxcarbazepine (OXC), as part of a switch off from carbamazepine (CBZ). Twenty-four to seventy-two hours following the switch, all patients developed intractable headache, despite the use of different symptomatic drugs. Complete recovery of the headache symptoms occurred only after OXC was discontinued. We discuss the potential mechanisms associated to OXC and status migrainosus, drug-induced headaches and uncontrolled headaches.

Brainstem astroblastoma: a case report and review of the literature

BACKGROUND

Astroblastoma is a rare glial tumor that occurs mainly in the cerebral hemispheres of young adults. Our purpose in writing this article is to report one case of astroblastoma located within the medulla and review the literature on this infrequent tumor.

METHODS

One case of astroblastoma was retrospectively reviewed. Presenting complaints, radiographic images, operative procedure, and histopathologic findings were recorded.

RESULTS

Contrast-enhanced MRI scan revealed a well-defined, well-circumscribed, contrast-enhanced cystic lesion approximately 16 mm in diameter within the medulla oblongata. Light microscopy demonstrated a papillary neoplasm composed of mildly pleomorphic cells with indistinct cytoplasmic borders. The nuclei were generally round to oval in shape. Occasional rosettes of tumor cells were seen around blood vessels. Mitoses were not seen within the submitted specimen. One small area of necrosis was present. The tumor exhibited thickened but not hyalinized blood vessel walls. The tumor cells exhibited strong staining for EMA and vimentin throughout the tissue section. Neurofilament, CAM 5.2, and CK immunostains were negative, except for rare positive staining of CK between cells and within rare tumor cells. Ki-67 was positive in small numbers of tumor nuclei, with an overall reactivity of 7%. By electron microscopy, the tumor nuclei had irregularly round to oval nuclei with moderate clumping of the chromatin, especially at the nuclear margins.

CONCLUSIONS

The combination of the radiologic and histopathologic characteristics of this tumor is necessary for making the diagnosis of astroblastoma. This article serves to summarize these characteristics as well as to report of an unusual location for this mainly hemispheric tumor.

From the archives of the AFIP: Pediatric orbit tumors and tumorlike lesions: neuroepithelial lesions of the ocular globe and optic nerve

Tumors and tumorlike lesions of the globe and optic nerve in children represent a different histologic spectrum than in adults; the imaging appearances of these lesions reflect their pathologic features. Retinoblastoma is a tumor of infancy and the most common intraocular tumor in children. There are heritable and nonheritable forms. The most common clinical finding is leukocoria. The differential diagnoses of this sign include several nonneoplastic lesions: Persistent hyperplastic primary vitreous is a congenital persistence of an embryonic structure causing a retrolental mass. The primitive vasculature may produce a septum in the posterior chamber. Coats disease is a vascular malformation of the retina that produces a lipoproteinaceous subretinal exudate. The vascular malformation enhances with intravenous contrast material, and the fat-containing subretinal exudate does not. Larval endophthalmitis is a granulomatous reaction to the dead or dying larvae of Toxocara canis or T. cati. The most important feature that allows differentiation of retinoblastoma from these so-called pseudoretinoblastomas is the presence of calcification in the former. Medulloepithelioma has two histologic forms; the teratoid type may contain calcifications, but it usually arises anteriorly from the ciliary body rather than posteriorly from the retina. Optic nerve glioma is the most common tumor of the optic nerve in children and is frequently associated with neurofibromatosis type 1. These gliomas are usually pilocytic astrocytomas and cause fusiform enlargement of the nerve.

1H MR spectroscopy in the assessment of gliomatosis cerebri

OBJECTIVE

Gliomatosis cerebri is a rare brain tumor with a short survival time; for this reason, it is difficult to establish the degree of aggressivity in vivo. The MR spectroscopic findings on this tumor often do not agree with choline level. The purpose of this study was to evaluate whether MR spectroscopy can be used to measure tumor choline levels and whether the findings give useful information about tumor growth rate and patient survival time.

SUBJECTS AND METHODS

We performed MRI and 1H MR spectroscopic studies on seven treatment-naive patients with gliomatosis cerebri and on 16 healthy volunteers. We then analyzed the association between survival time and levels of choline (Cho) and N-acetyl aspartate (NAA) normalized to creatine (Cr).

RESULTS

The results showed a statistically significant (p = 0.05) inverse relation between Cho/Cr ratio and survival time. In addition, NAA/Cr ratio was significantly lower in the patient group than in the control group (p = 0.001).

CONCLUSION

Cho/Cr ratio measured with MR spectroscopy seems to be related to survival time, possibly explaining the inconsistent findings previously reported for this parameter.