Fibrous Meningioma Research Articles

Differentiation Researches on the Meningioma Subtypes by Radiomics from Contrast-Enhanced Magnetic Resonance Imaging: A Preliminary Study

Meningioma subtypes are one of the most common key points to the treatment and prognosis of patients. The purpose of this study was to investigate the differential diagnostic value of radiomics features on meningioma. A total of 241 patients with meningioma who had undergone tumor resection were randomly selected including 80 with meningothelial meningioma, 80 with fibrous meningioma, and 81 with transitional meningioma. These meningiomas were divided into 4 groups including: meningothelial versus fibrous (group 1), fibrous versus transitional (group 2), meningothelial versus transitional (group 3), and meningothelial versus fibrous versus transitional (group 4). All patients were examined using the same magnetic resonance scanner (GE 3.0 T) and the preoperative contrast-enhanced T1-weighted images were available. Radiomics features from the contrast-enhanced T1-weighted images of 241 patients were evaluated by 2 experienced radiology specialists. A total of 385 radiomics features were extracted from the images of each patient. Several preprocessing methods were applied on the radiomics dataset to reduce the redundancy and highlight differences between different meningioma before the Fisher discrimination analysis was adopted and leave one out cross validation methods were used for the model validation. The differentiation accuracies of the Fisher discriminant analysis model for groups 1, 2, 3, and 4 were 99.4%, 98.8%, 100% and 100%, respectively; leave one out cross validation method was achieved for group 1, 2, 3, and 4 with the accuracies of 91.3%, 95.0%, 100%, and 94.2%, respectively. Radiomics features and the combined Fisher discriminant analysis could provide satisfactory performance in the preoperative differential diagnosis of meningioma subtypes and enable the potential ability for clinical application.

MUC4 expression in meningiomas: under‐recognized immunophenotype particularly in meningothelial and angiomatous subtypes

MUC4 is a transmembrane glycoprotein that plays a role in cell growth signalling and is expressed in various epithelial tissues. Gene expression profiling and immunohistochemical analyses revealed that MUC4 is also constantly and specifically expressed in low-grade fibromyxoid sarcomas and sclerosing epithelioid fibrosarcomas among the mesenchymal tumours, and immunohistochemical detection of MUC4 is extremely useful for their diagnoses. In our routine pathological practice, we noticed that meningiomas are also often positive for MUC4, which has not yet been reported previously, despite the extensive scrutiny of its expression in soft tissue tumours. We examined immunohistochemically the expression of MUC4, progesterone receptor (PgR) and somatostatin receptor 2A (SSTR2A) in 140 meningiomas of various histological subtypes and 123 other mesenchymal tumours, including intracranial or sinonasal tumours and peripheral nerve sheath tumours. MUC4 was expressed in 130 meningiomas (92.9%). MUC4 expression was constant and almost diffuse in meningothelial and angiomatous subtypes, whereas it was limited in 5% or fewer tumour cells or absent in 26 of 28 fibrous meningiomas. All other mesenchymal tumours examined were negative for MUC4. PgR and SSTR2A were expressed in 94 (67.1%) and 134 (95.7%) meningiomas, respectively. Five of six SSTR2A-negative meningiomas focally expressed MUC4. MUC4 is expressed variably but almost consistently in meningiomas, particularly in meningothelial or angiomatous subtypes. Its immunohistochemical detection is useful to distinguish meningiomas from other intracranial or head and neck mesenchymal tumours, particularly those with epithelioid features. Our study could expand a variety of MUC4-positive mesenchymal tumours.

Ossified extradural en-plaque meningioma of the cervical spine

A 57-year-old woman sustained gradually progressive sensorimotor disturbance in the left upper extremity for one year. Neurological examination found a diminished sensation below the left C7 dermatome and reduced strength in the left interosseous muscles. Computed tomography of the cervical spine revealed a high density mass at C7, in the left dorsal part of the spinal canal. Magnetic resonance imaging found an enhancing, en-plaque tumor at C6-T1, involving a non-enhancing part, and considerable compression of the spinal cord. The patient underwent tumor resection through hemilaminectomy of C5-C7. The tumor was located epidurally, highly fibrous including bony-hard parts, and severely adhered to the dura mater that necessitated drilling for debulking. A subtotal resection was achieved and histological diagnosis was a fibrous meningioma with metaplastic ossification. Ossification may be a pathognomonic appearance of spinal extradural meningiomas that makes resection maneuvers difficult.

Endoscopic Endonasal Craniofacial Surgery for Recurrent Skull Base Meningiomas Involving the Pterygopalatine Fossa, the Infratemporal Fossa, the Orbit, and the Paranasal Sinus

Skull base meningiomas carry a nonnegligible risk of recurrence. In particular, those arising from the sphenoid wings or middle cranial fossa penetrate into extracranial regions, uncommonly showing massive expansion into the craniofacial regions on recurrence. The role of endoscopic endonasal surgery for those intractable lesions remains unclear. We performed endoscopic endonasal craniofacial surgery for 8 recurrent meningiomas invading into the pterygopalatine fossa, infratemporal fossa, nasopharynx, paranasal sinus, or orbit, comprising 2 meningothelial and 1 fibrous meningiomas (World Health Organization [WHO] grade I), 3 atypical and 1 clear cell meningiomas (grade II), and 1 anaplastic meningioma (grade III). All were large (15-80 cm3; median, 45 cm3) and highly vascularized. All 8 tumors were sufficiently resected. Gross total resection of the craniofacial part of the lesions was achieved in 5 patients (62.5%). In 3 patients with WHO grade I meningiomas and 1 with grade II, tumors were successfully controlled as of the last follow-up. In 4 patients with WHO grade II or III meningiomas, craniofacial lesions were controlled, whereas original intracranial lesions were poorly controlled and became critical. We consider the endoscopic endonasal approach as an acceptable, less-invasive alternative for recurrent craniofacial meningioma. Although all these cases were relatively large and highly vascularized, preoperative endovascular embolization of the feeding arteries contributes to significantly reducing vascularity of the tumors, and local control of the craniofacial lesions was successfully achieved in all cases. Endoscopic endonasal craniofacial surgery enabled sufficient mass reduction without disfiguring facial incisions.

The role of three-dimensional pseudo-continuous arterial spin labelling in grading and differentiating histological subgroups of meningiomas

To evaluate the usefulness of pseudo-continuous arterial spin labelling (pCASL) imaging in grading and differentiating histological subtypes of meningiomas. In this prospective study, conventional magnetic resonance imaging (MRI) with contrast-enhanced T1-weighted images and pCASL were acquired with a 3 T MRI system before surgery in 125 consecutive patients with suspected meningiomas. Finally, the perfusion parameters were collected from 84 grade I and 23 grade II meningiomas. On the pCASL perfusion map, the mean absolute cerebral blood flow (CBF) values from the meningioma (CBFtumour), peritumoural oedema (CBFPTO), white matter of contralateral centrum semi-ovale (CBFwm) and normal grey matter (CBFgm) were calculated. Additionally, the associations of these perfusion parameters with the value of ki-67 index were analysed. The CBFwm value correlated negatively with the largest diameter of the tumour, which limited its usage as a reference for ratio calculation. The CBFtumour values of grade II and grade I meningiomas did not differ significantly: 137.36±71.85 ml/min/100 g versus 123.58±135.80 ml/min/100 g (p=0.641). The CBFPTO value was higher for grade II meningioma as than for grade I meningiomas: 30.30±15.56 ml/min/100 g versus 22.33±9.87 ml/min/100 g (p=0.037). The CBFtumour value was highest in angiomatous meningioma and lowest in fibrous meningioma, thus enabling the differentiation of subtypes of meningioma. The CBFtumour value did not correlate with the ki-67 index of meningioma. The CBFPTO value, rather than the CBFtumour value, from pCASL imaging may serve as a key factor in distinguishing different grades of meningiomas. Moreover, angiomatous meningiomas and fibrous meningiomas can be identified by CBFtumour value.

Neuroendoscopic resection of meningiomas in lateral ventricular trigonum

Objective To discuss the surgical strategy and therapeutic effect of neuroendoscopic resection of meningiomas in lateral ventricular trigonum. Methods A retrospective analysis of 5 cases with meningiomas in lateral ventricular trigonum was conducted, who were diagnosed and underwent operations in Department of Neurosurgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine from March 2015 to November 2015. All patients underwent preoperative thin-section computed tomography (CT) scans and contrast-enhanced magnetic resonance imaging (MRI). For large intraventricular meningiomas, examinations including computed tomography angiography (CTA), magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) as well as partial vascular interventional embolization were desirable in order to deal with the tumor feeding artery as soon as possible. In the whole process of operation, tumors were resected under the neuroendoscope assisted by neuronavigation, ultrasonic suction system, and a novel brain retractor device. Results The meningiomas in lateral ventricular trigonum in all 5 cases were resected completely and were pathologically determined to be fibrous meningiomas. The immunohistochemical analysis showed that Ki-67 index was lower than 1%. The surgical channels were well healed with no brain edema in operation area or ventricle enlargement. Compared with 8 similar patients in other treatment modalities, the mean hospitalization time was significantly shorter [(17.5±4.3) d vs (11.0±2.9) d]. No complications, such as epilepsy, hydrocephalus or visual field defects, were observed postoperatively during the follow-up lasting 6 months to 1 year. Conclusion The neuroendoscope combined with neuronavigation, ultrasonic suction system and the novel brain retractor device could help accurately locate deep intracranial tumors, facilitate real-time intraoperative protection of surrounding vessels and functional structures, and achieve maximal safe resection of tumors. Key words: Meningioma; Lateral ventricle; Neuroendoscopy; Neuronavigation; Treatment outcome

Aneurysm of azygos anterior cerebral artery associated with falcine meningioma: Case Report and review of the literature

Background:The azygos anterior cerebral artery (ACA) is an uncommon intracranial vascular anomaly of the circle of Willis. Identification of aneurysm from azygos ACA with anterior falcine meningioma is an extremely rare association. The aim of the present study is to report the case of an adult female with a ruptured aneurysm from azygos ACA in association with an anterior falcine meningioma.Case Description:A 65-year-old female was admitted in the Emergency Department reporting sudden onset of severe headache. Computed tomography (CT) revealed an intracerebral hematoma and an expansive calcified lesion. AngioCT showed the presence of a large aneurysm in the distal portion of the azygos ACA. During the surgical procedure, it was possible to visualize the aneurysm in contact with an expansive lesion arising from the anterior third of the falx. Microsurgical clipping of the aneurysm was performed uneventfully and partial resection of the tumor was done. Histopathological analysis showed a fibrous meningioma. The patient was discharged home on the seventh postoperative day in good clinical conditions.Conclusion:The association of aneurysm from azygos ACA and falcine meningioma is an extremely rare event and must be remembered when expansive masses are present in the vicinity of vascular lesions.

Intrakranijinės besimptomės meningiomos daugybinės metastazės į plaučius: klinikinis atvejis

ĮvadasŠis klinikinis atvejis yra nenumatyto ligos pasireiškimo. Tikime, kad jis privers apgalvoti jau žinomą gerybinių navikų, tarp jų ir meningiomos, elgseną, kuri gali įgyti nepriklausomą metastazinį potencialą. Kadangi gerybinių navikų metastazės yra diagnozuojamos pavėluotai, šiuo pavyzdžiu siekiame plėsti klinicistų sąmoningumą ir budrumą nagrinėjant ligas, kurioms būdingos neįprastos klinikinės apraiškos. Tai pirmasis Lietuvoje aprašytas intrakranijinės meningiomos metastazavimo į plaučius atvejis.Atvejo pristatymasAprašome klinikinį atvejį 66 metų moters, kurią vargino nuolatinis produktyvus kosulys, dusulys, karščiavimas ir silpnumas, at­sirandantis fizinio krūvio metu. Atliktos krūtinės ląstos rentgenogramos parodė daugybinius, mažus, apvalios formos mazgus plaučiuose. Po atliktos torakoskopinės plaučių audinių rezekcijos histopatologinio tyrimo metodu konstatuota meningioma. Atliktas galvos smegenų magnetinio rezonanso tyrimas, kurio išvada – kairiajame tilto ir smegenėlių kampe su dangalais susijęs, kontrastinę medžiagą gerai kaupiantis, smulkus navikas, išsiplėtusios giliosios smegenų venos. Histologinė smegenų darinio išvada remiantis Pasaulio sveikatos organizacijos klasifikacija – pirmo laipsnio fibrozinė meningioma.IšvadaMeningioma yra traktuojama kaip neinvazinis ir nemetastazuojantis, gerybinis, intrakranijinis navikas. Metastaziniai židiniai yra neįprasti šios ligos eigai, dėl to gali būti diagnozuoti pavėluotai. Klinikinis atvejis paneigia literatūroje nurodytus rizikos veiksnius, kuriais remiantis būtų galima numatyti galimą meningiomos metastazavimą, ir tai leidžia priskirti meningiomą neprognozuojamos eigos navikams.

Evaluation parameters between intra-voxel incoherent motion and diffusion-weighted imaging in grading and differentiating histological subtypes of meningioma: A prospective pilot study

PurposeTo prospectively evaluate the usage of intra-voxel incoherent motion (IVIM) magnetic resonance imaging (MRI) parameters in grading and differentiating histological subtypes of meningiomas and in comparing their ability with the traditional diffusion-weighted imaging (DWI) parameter (apparent diffusion coefficient, ADC). MethodsIn this prospective study, 102 participants underwent IVIM MRI and DWI. Traditional DWI and IVIM MRI were performed by using 2 b values (0, 1000s/mm2) and 12 b values (0–3500s/mm2), respectively. Finally, the values of ADC and IVIM parameters were collected from 72 Grade I and 11 Grade II meningiomas. ResultsThe mean ADC values of Grade II and Grade I meningiomas were 0.909±0.268×10−3mm2/s and 0.905±0.194×10−3mm2/s, respectively, p=0.967. The D values were lower in Grade II meningiomas than in Grade I meningiomas (0.459±0.072×10−3mm2/s vs. 0.524±0.030×10−3mm2/s, respectively, p=0.005). In ROC curves, the cut-off D value that separated Grade II meningiomas from Grade I meningiomas was 0.479×10−3mm2/s with a sensitivity of 90.9% and a specificity of 76.7%. The secretory and angiomatous meningiomas had higher IVIM parameters than the other subtypes (all p<0.05). D* was significantly lower in fibrous meningiomas than in other meningiomas (2.783±1.179×10−3mm2/s vs. 5.125±1.918×10−3mm2/s, p<0.001). D, rD and rf values correlated negatively with Ki-67 index while D* and rD* value had positive relation with Ki-67 values. ConclusionIVIM MRI is a promising technique for distinguishing different grades of meningiomas. Different subtypes of meningiomas have different IVIM features, which may help to treatment decision and prognosis evaluation.

MNGO-21GENOTYPING OF MENINGIOMA BY TARGETED AMPLICON SEQUENCING USING MiSeq

BACKGROUND: Meningiomas are the most common primary brain tumors, accounting for about 27% of all intracranial tumors. Loss of Neurofibromin 2 (NF2) is found in about half of sporadic meningiomas, and recently, mutations in TRAF7, KLF4, AKT1, and SMO are reported in non-NF2 meningioma. To establish practical genotyping methods, we performed targeted amplicon sequencing with 45 meningioma specimens and evaluated the association with clinicopathological features. METHODS: Frozen samples of 45 meningiomas were fixed with PAXgene Tissue System (QIAGEN) and embedded in paraffin (PFPE). Amplicon sequencing panel targeted NF2, TRAF7, KLF4, AKT1 and SMO were designed by GeneRead Mix-n-Match panel and Custom panel (QIAGEN). Genomic DNA was extracted from PFPE tissues and libraries were prepared using GeneRead DNAseq Targeted Panels V2 (QIAGEN). The libraries were sequenced by the MiSeq (Illumina). The raw read data obtained from amplicon sequencing were processed by GeneRead Panel Variant Calling service for analysis of mutations and copy number alterations (CNA). RESULTS: Thirty three cases (73%) harbored NF2 loss, in which 20 cases (61%) simultaneously carried NF2 mutation. Mutations in TRAF7, KLF4, AKT1, and SMO were observed in 6 (13 %), 4 (9 %), 2 (4 %) and 0 (0%) cases, respectively. Altogether, 40 of 45 case (89 %) carried at least one or more gene alteration including mutations in 5 genes listed above and NF2 loss. Result of genotyping was correlated with histological subtypes as follows. All of nine fibrous meningiomas carried NF2 loss, while all of 4 meningiomas with secretory component carried both TRAF7 and KLF4 mutations. A case of chordoid meningioma harbored only AKT1-E17K mutation. CONCLUSIONS: Here we established the clinical sequence system for meningioma by targeted amplicon sequencing with desktop sequencer in which we demonstrated favorable results for CNAs as well as mutations.

A rare case of transitional meningioma.

A rare case of transitional meningioma.

Sox10 is superior to S100 in the diagnosis of meningioma.

Meningiomas are the most common primary cranial tumor arising in the central nervous system and its coverings, constituting 35.5% of primary brain tumors. Schwannomas account for 8.3% of primary neoplasms of the central nervous system. Occasionally these tumors can show overlapping morphology, most conspicuously in the fibrous variant of meningioma. In such cases, immunohistochemistry can help to establish a definitive diagnosis. Currently S100 is the most commonly used immunohistochemical stain to show neural crest differentiation in tumors. This may lead to potential misclassification of meningeal tumors, as up to 70% of fibrous meningiomas can show S100 expression. Our study sought to determine if Sox10 would prove a more specific alternative to S100 in cases of meningioma when the differential diagnosis includes schwannoma. We compared the mRNA expression of S100B and Sox10 using the publicly available GSE16581 meningioma dataset. We then studied Sox10 and S100 protein expression using immunohistochemistry in 147 cases of meningioma using tissue microarrays (TMA) and 19 cases of fibrous meningioma using full cross-sections (FCS). Sox10 and S100B mRNA expression in GSE16581 showed no significant correlation in meningothelial tumors (r=-0.002, P=0.989). By immunohistochemistry, S100 was positive in 14/19 (73.7%) of FCSs and 71/147 (48.3%) of TMA tumors, whereas Sox10 (protein name) was positive in only 1/19 (5.3%) of FCSs and 3/147 (2.0%) of TMA tumors. In summary, Sox10 is superior to S100 in the differential diagnosis of schwannoma and meningioma.

Focal cortical dysplasia in meningioangiomatosis

Meningioangiomatosis is a rare, benign, developmental, or hamartomatous lesion which may involve the leptomeninges and underlying brain parenchyma. Histologically, meningioangiomatosis is marked by a proliferation of blood vessels in the parenchyma, rimmed by collars of spindled meningothelial cells. There are anecdotal reports of an association of meningioangiomatosis with focal cortical dysplasia. We retrospectively analyzed the clinical, histopathologic, and treatment outcomes of 16 patients with a diagnosis of meningioangiomatosis, specifically investigating these cases for evidence of adjacent focal cortical dysplasia. Patients ranged in age from 1 to 34 years (median 18), 12 of whom had medically-intractable epilepsy as their presenting symptom. No patients in this study had a confirmed diagnosis of neurofibromatosis type II. Four patients (25%) were found to have fibrous meningiomas associated with the meningioangiomatosis. Ten of the 12 patients (83%) who had adequate tissue excised adjacent to the meningioangiomatosis demonstrated evidence of focal cortical dysplasia, with 6 of those (60%) classified as Palmini type IA, and 4 patients (40%) classified as Palmini type IIA. Seven of the patients (44%) had no post-operative seizures, and were off anti-epileptic drugs, while 2 patients relapsed, and required pharmacologic treatment for seizure control. This study therefore presents evidence to support inclusion of meningioangiomatosis as a focal cortical dysplasia-associated entity, as suggested by the ILAE classification (type IIIc). As focal cortical dysplasia is a developmental malformation, its association with meningioangiomatosis supports a developmental etiology of sporadic meningioangiomatosis.

Pseudo-continuous arterial spin labeling reflects vascular density and differentiates angiomatous meningiomas from non-angiomatous meningiomas.

Pseudo-continuous arterial spin labeling (PCASL) can measure tumor blood flow (TBF) reliably. We investigated meningioma TBF using PCASL and assessed for any correlation with histopathological microvascular density (MVD) and the World Health Organization (WHO) classification. Conventional MRI with contrast T1-weighted images and PCASL were acquired with a 3 T scanner before surgery in 25 consecutive patients with meningiomas. Using the PCASL perfusion map, the mean and maximum TBF were calculated from regions of interest placed in the largest cross-sectional plane of each tumor. Tissue sections from 16 patients were stained with CD31 to evaluate MVD and were assigned a WHO classification. The TBFs were statistically compared with MVD and the histopathological meningioma subtypes. There were 16 meningothelial meningiomas, four angiomatous meningiomas, two fibrous meningiomas, one transitional meningioma, and two atypical meningiomas. We observed significant correlation between MVD and both mean and maximum TBF (p < 0.05). The mean and maximum TBF ((mean)TBF, (max)TBF) in angiomatous meningiomas are significantly higher than that in non-angiomatous meningiomas (p < 0.05). PCASL is useful in assessing meningioma vascularity, and in differentiating angiomatous meningiomas from non-angiomatous meningiomas.

Histological and morphometric characteristics of supratentorial meningiomas of the brain

The development of modern methods of clinical diagnosis and surgical treatment of CNS tumors necessitates reliable morphological verification of the tumor lesion with the definition of its histogenesis, morphological variant and degree of malignancy. Works on computer analysis of morphometric data of CNS tumors are rare. Meanwhile, histomorphometric studies have potential value for diagnostic purposes in the study of brain tumors.Goal: to conduct histological and morphometric analysis of the cellular composition of meningiomas, needed to improve their differential diagnosis.Material and methods. We studied surgically removed meningiomas in 39 patients aged from 40 to 66 years. 7 meningothelial meningiomas, 4 angiomatous, 6 fibrous, 7 transitional, 6 psammomatous, 2 atypical and 7 anaplastic meningiomas were included in the study.Histomorphometric analysis was performed on hematoxylin and eosin (H&amp;E)-stained histological sections. Calculation of quantitative indices was conducted using a computer system for digital image analysis KS 200 (Kontron Elektronik,Germany, lic. № 0200299). Studied objects (cell nuclei) were examined using morphometric measurements: cross-sectional area (AREA), the diameter of the object (the diameter of irregularly shaped objects was calculated through their equivalent area – parameter DCIRCLE). Coefficients (indices) of the form (FC) and elongation (EC) were used as additional morphometric characteristics of the studied objects.Results. Meningothelial meningiomas were represented by large cells with light nuclei with diffusely located fine chromatin. Most cells had a polygonal shape and did not have clear boundaries. The cell density in the field of vision averaged 55±5, cross-sectional area of the nuclei 45,24±4,77 µm2, FC and EC respectively 0,87±0,02 and 0,71±0,1.Transitional meningiomas were characterized by combined areas of meningothelial, syncytial type and areas with typical fibroblastic differentiation of cells. Two groups of cells were identified which differed in morphometric parameters: a cross-sectional area of nuclei, respectively 49,78±5,93 and 30,59± 4,16 µm2 and FC 0,87±0,05 and 0,67±0,10. EC were respectively 0,54±0,13 and 0,43±0,11.The predominant cell type in fibrous meningiomas were fibroblast-like arachnoendotheliocytes with oval, elongated nuclei containing fine chromatin, hyperchromic nuclei were frequent. Cells formed bundles going in different directions, concentric structures and psammoma bodies were often met. Tumor cell density was 46,6±13,22. In areas with fibrous extracellular matrix cells with cross-sectional area of the nuclei 37,13±4,47 µm2 dominated.Atypical meningiomas were characterized by increased cellularity – 82 cells in the field of view, more pronounced nuclear polymorphism, mitosis and the presence of small areas of necrosis. The cross sectional area of the nuclei of tumor cells was 65,78±16,97 µm2.The cross sectional area of the nuclei is significantly increased in atypical and anaplastic meningiomas, which reflects the increase in the degree of atypia (linear relationship between the degree of increasing area of the nuclei and Grade - strong positive correlation, Pearson coefficient r=0,89, p&lt;0.05).Conclusions. Conducted investigation indicates the feasibility of using a morphometric method for improving the diagnosis of various meningiomas. Prospects for further research in this area suggest the selection of reliable morphometric criteria for estimation of the recurrence rate and aggressiveness of meningiomas growth.

A Large Intramedullary Neurofibroma in the Thoracic Spinal Cord: Case Report

Neurofibromas are occasionally present in spinal roots; however, an intramedullary neurofibroma is especially rare. Although a few cases of intramedullary neurofibromas in cervical spinal cord have been reported, to the best of our knowledge, there are no reports of intramedullary neurofibromas in thoracic spinal cord, and moreover, no reports have clearly reported immunohistochemical findings. We report a rare case of a large intramedullary neurofibroma in the thoracic spinal cord and show immunohistochemical examination of the tumor. A 52-year-old man presented with a 2-year history of progressive gait disturbance. Neurological examinations demonstrated complete motor and sensory deficit of his legs. Magnetic resonance imaging of the thoracic spine demonstrated an intramedullary enhancing mass within the spinal cord between T4 and T5 levels. The patient underwent T3–T6 laminectomy surgery. The dura mater was opened to reveal fusiform dilatation of the spinal cord and a midline myelotomy was performed. An intramedullary mass was revealed and could be resected totally. Histopathological examination revealed that the tumor cells exhibited spindle-shaped and wavy nuclei with abundant collagen, which resembled schwannoma or fibrous meningioma. By immunohistochemical examination, some tumor cells were positive for S-100 proteins; however, most tumor cells were strongly positive for CD34. From these pathological findings and immunohistochemical reactions, we diagnosed the intramedullary tumor as a neurofibroma.

Marginal zone B-cell lymphoma involving a longstanding fibrous meningioma: an initial manifestation of systemic disease

The combined presence of meningioma and lymphoma involving the dura is exceptionally rare. A 62-year-old woman, radiologically diagnosed with meningioma 14 years prior but never treated, presented with headaches and visual symptoms. Magnetic resonance imaging demonstrated significant growth of the mass. Surgical resection yielded a composite meningioma and marginal zone B-cell lymphoma. Subsequent systemic workup revealed bone marrow involvement. Low-grade lymphomas rarely metastasize to the central nervous system. When they do, it is usually a result of large cell transformation and typically marks a late event in the course of the disease. This case highlights the necessity of adequate sampling of meningiomas and of including low-grade lymphoma in the differential diagnosis of meningiomas with prominent lymphocytic infiltrates. In addition, this case emphasizes that all patients with lymphoma involving the central nervous system, even when low grade, should receive a full systemic workup.

Molecular alterations in meningiomas: association with clinical data

The aim of our study was to evaluate the frequency of deletions on chromosomes 1, 9, 10, 14, 18 and 22 in 75 benign and 15 atypical meningiomas and correlate them with clinical findings. Paired normal and tumor DNA samples were analyzed for loss of heterozygosity (LOH), using 24 microsatellite markers and PCR techniques. Statistical analysis showed that deletions on chromosomes 14 and 18 were significantly associated with tumor grade of meningiomas (p = 0.048 and p = 0.03, respectively). In addition, we found a marginally increased frequency of LOH on chromosome 9 in atypical meningiomas (p = 0.06). Interestingly, LOH on chromosome 14 was significantly associated with tumor size (p = 0.049), as the risk of developing a tumor of more than 4 cm in diameter was 6-times the risk of developing tumor with diameter below 4 cm. The most frequent genetic abnormality in meningiomas is 22 LOH, which seems to be confirmed by the present study in which high frequency of such abnormality was observed (67%). We found associations between chromosome 22 status and histological subtype. LOH on chromosome 22 was more frequent in fibrous meningiomas than in the meningothelial variant (p = 0.001). Besides that, we found a relationship between 22 LOH status and tumor localization: the frequency of LOH in skull base-localized tumors was significantly lower compared to parasagittal meningiomas (p = 0.0004). Our results indicated that allelic loss on chromosomes 9, 10, 14, 18 and 22 may be associated with meningioma pathogenesis and progression.

Histopathological classification and location of consecutively operated meningiomas at a single institution in China from 2001 to 2010

Background Meningioma is one of the most common primary tumors of the central nervous system, but there are not many detailed studies on the sex, age, subtypes and locations of large series. This study was a retrospective analysis of the characteristics of meningioma cases consecutively operated on at a single institution in China from 2001 to 2010. Methods This study investigated the demographic background of 7084 meningioma cases, and the subtypes and locations of the tumors. Sex and age distributions were analyzed, and the pathological subtypes were classified according to the World Health Organization (WHO) classification. The location of the meningiomas was also categorized. Results The female:male ratio of the 7084 cases was 2.34:1. The mean age was 51.4 years (range, 11 months-86 years). The mean age of cases of WHO grade I meningioma was significantly older than that of grade II or III meningiomas (P &lt;0.001, Fisher's Least Significant Digit test). There was a significantly higher female:male ratio in WHO grade I meningiomas than in grade II or grade III meningiomas (2.57, 1.03 and 0.76, respectively; P &lt;0.001, χ2 test). Meningothelial (n=2061) and fibrous meningiomas (n=3556) were the most common subtypes, comprising 79.3% of all meningiomas. All meningioma cases were classified into 23 locations in this study, with the cerebral convexity the most common site (38.33%, n=2722). Cases with uncommon locations such as extra-cranial and sylvian fissure meningiomas were also present in this series. Conclusions Female predominance was found for benign meningiomas, while malignant subtypes showed male predominance. The mean age of patients with WHO grade I meningiomas was older than that of patients with higher-grade tumors. Meningothelial and fibrous meningiomas were the most common subtypes. The cerebral convexity was the most common meningioma location.

A Tentorial Venous Hemangioma Presenting As an Extra-Axial Mass in the Ambient Cistern: A Case Report

Although venous hemangiomas are one of the most common soft-tissue tumors, venous hemangiomas in the central nervous system are extremely rare. We present an unusual case of venous hemangioma originating from the interdural space of the tentorium. A 32-year-old woman was incidentally found to have extra-axial mass occupying the left ambient cistern. This tumor was observed for the first 4 years as it was completely asymptomatic. Surgical resection was later recommended when the tumor grew. The mass originated from between the two layers of the anteromedial tentorial incisura. There were no findings indicative of previous hemorrhage inside the mass. The matrix of the mass was firm and vascular, resembling a fibrous meningioma. Gross total resection was achieved without any neurological deficit. Pathological examination revealed a dense fibrous connective tissue with a proliferation of vessels marked by thickened walls. A spindle cell proliferation in the vessel walls did not stain with the antibody to S-100 protein. Movat stain demonstrated the venous character of the vessels. These results were histologically compatible with a venous hemangioma. Albeit extremely rare, a venous hemangioma, a distinct clinical and pathological entity from a venous angioma, can present an intracranial mass lesion.