Intraparenchymal clear cell meningioma of the brainstem in a 2-year-old child. Case report and literature review

Intraparenchymal atypical meningioma in the posterior fossa: a case report and literature review

Intraparenchymal meningiomas without dural attachments are extremely rare. A 32-year-old female adult was admitted to our hospital, complaining of occasional dizziness. The patient had no neurological deficits. MRI demonstrated a lesion with mild edema located in the left cerebellar parenchyma. CT revealed calcification within the mass. Gross total resection was achieved. The histopathological examination indicated that the lesion was an atypical meningioma (WHO-II). We herein report an extremely rare case of an intraparenchymal meningioma located in the left cerebellar hemisphere. The significance of the differential diagnosis of lesions in the cerebellum should be emphasized.

Primary Intraparenchymal Meningiomas: A Case Report and a Systematic Review

BACKGROUND

Primary intraparenchymal meningiomas are exceedingly rare and often challenging to diagnose, given their misleading radiologic features. It is hypothesized that they arise from the cap cells of the pia mater that enter the brain via penetrating blood vessels during brain development. We systematically reviewed and analyzed previously reported features of primary intraparenchymal meningiomas in terms of radiography, presenting symptoms, and histopathology.

METHODS

A literature search of the Web of Science and PubMed databases and crossed references was performed in March 2021, per PRISMA guidelines, with no restrictions regarding publication date. Data regarding demographic features, clinical, radiographic, and histopathologic characteristics were extracted.

RESULTS

A total of 52 patients (including the reported case) were included in this review. The mean age was 21.1 years (range, 0.3-66 years) with a male/female ratio of 1.9:1. The most common localizations of intraparenchymal meningiomas were in the frontal (30.8%) and temporal (21.2%) lobes. Cyst formation was more readily observed and was noted in 51.4% of patients. Histopathology showed a higher incidence of World Health Organization grade II (14/52, 26.9%) and World Health Organization grade III (7/52, 13.5%) of primary intraparenchymal meningiomas.

CONCLUSIONS

We present a comprehensive analysis of every reported primary intraparenchymal meningioma. Because of their rarity and capacity to mimic other more common intra-axial tumors, they represent a diagnostic challenge. This systematic review highlights the importance of paying attention to atypical intra-axial lesions, with a particular reflection on the discrepancy between clinical characteristics and imaging features.

Giant Intraparenchymal Meningioma in a Female Child: Case Report and Literature Review

BACKGROUND

Intraparenchymal meningiomas without dural attachment are extremely rare, especially in female children. To our knowledge, fibrous intraparenchymal meningioma located in the temporal lobe has never been reported in female children. The significance in the differential diagnosis of lesions in the temporal lobe should be emphasized.

CASE PRESENTATION

A 12-year-old girl was admitted to our hospital, complaining of recurrent generalized seizures for 2 months. Magnetic resonance imaging demonstrated a solid lesion located in the temporal lobe. The lesion underwent gross total resection. Histopathological examination indicated that the lesion was a fibrous meningioma. Postoperative rehabilitation was uneventful.

CONCLUSION

This case report presents an extremely unusual intraparenchymal fibrous meningioma of the temporal lobe with peritumoral edema and reviewed 21 intraparenchymal meningioma cases in children and to discuss the clinical presentation and treatment, differential diagnosis, and radiological features.

An Aggressive Extension of Dumbbell-Type Pediatric Skull Base Meningioma: A Case Report with Review of the Literature

BACKGROUND

Pediatric meningiomas account for less than 2% of pediatric brain tumors. Pediatric clear cell meningiomas (CCMs) occurring in the posterior fossa are particularly rare. Therapeutic strategies differ among the previous pediatric CCM case reports. Therefore, to clarify the clinical features of pediatric CCMs, we report a rare case of dumbbell-type pediatric CCM and a corresponding literature review.

CASE DESCRIPTION

A 7-year-old boy with complaints of headache, left facial palsy, dysarthria, and left-sided ataxic gait was emergently admitted to our hospital. His consciousness level was slight stupor, with Glasgow Coma Scale score 3-5-6, and he showed left ptosis, dysarthria, and ataxias of the left trunk and extremities. Magnetic resonance imaging (MRI) scan showed acute obstructive hydrocephalus because of the tumor's compression of the brainstem. The dumbbell-shaped tumor extended from the lateral wall of the cavernous sinus, through the left Meckel's cave, to the cerebellopontine angle. Physical examination and perioperative MRI scan showed no evidence regarding neurofibromatosis type I or II. The tumor was removed in a 2-staged operation. Postoperative proton therapy was done to treat some residual tumors. One year after postoperative proton therapy, there is no recurrence, and apart from left corneal and facial hypesthesia, he is healthy.

CONCLUSIONS

We reported a rare case of pediatric skull base-type CCM with huge extension originating from the anteromedial wall of Meckel's cave firmly adhered to the cavernous sinus wall to the posterior fossa that was successfully treated with surgery and postoperative proton therapy. CCM has a high recurrence rate; therefore, careful prolonged follow-up is needed.

Pediatric meningiomas: a report of 5 cases and review of literature

PURPOSE

The purpose of this paper is to provide novel insight into the rare pediatric meningiomas.

METHODS

We retrospectively analyzed pediatric surgical cases of meningioma during 2002 to 2017 in our institution. The preoperative, intraoperative, and the postoperative status were collected to find any unique features that has not reported in the past.

RESULTS

Nine surgeries out of 5 patients were identified. The mean age was 7 years old (range 1-14 years old). Four patients were females. The mean tumor diameter was 52 mm (range 23-81 mm). The tumor locations were optic nerve sheath, Sylvian fissure, parasagittal, trigone of the lateral ventricle, and cerebellopontine angle. The Sylvian fissure meningioma without dural attachment (MWODA) was found in a 15-month-old female. A relapsed parasagittal meningioma showed regression in histological grade and residual tumor demonstrated spontaneous regression. In the initial surgeries, Simpson grade 1 resection was achieved in 2 cases. The pathological diagnoses were 1 meningothelial, 1 metaplastic, 2 atypical, and 1 clear cell meningiomas. The mean postoperative follow-up period was 71 months. Three patients experienced recurrence of the tumor. At the latest follow-up, all patients were free of radiological tumor recurrence or regrowth with a mean follow-up of 4 years (range 1-6.9 years). All patients were in the modified Rankin scale of 0-1.

CONCLUSIONS

MWODA is not considered to be rare in pediatric meningioma and should be included in the differential diagnosis. We presented a histologically regressed relapsed meningioma, which spontaneously regressed after subtotal resection. In the case of recurrent meningioma, surgical resection and adjuvant radiation therapy could be effective for long-term control of the tumor.

Clinical Features, Treatment, and Prognostic Factors of 56 Intracranial and Intraspinal Clear Cell Meningiomas

OBJECTIVE

Intracranial and intraspinal clear cell meningiomas (CCMs) are rarely reported because of their extremely low incidence, and the current understanding of CCM is poor. The purpose of this study was to analyze the incidence and the clinical, radiologic, pathologic, and prognostic features of intracranial and intraspinal CCMs.

METHODS

Among 14,310 cases of intracranial and intraspinal meningiomas that were surgically treated between 2006 and 2016 at Beijing Tian Tan Hospital, 56 were chosen for analysis and retrospectively reviewed. To determine which parameters were associated with longer progression-free survival (PFS) and overall survival (OS), statistical analysis was performed.

RESULTS

CCMs accounted for approximately 0.39% of all intracranial and intraspinal meningiomas. Patients with CCM had a mean age of 32.3 years and there was a female predilection (20 males and 36 females). Gross total resection was achieved in 35 cases, and subtotal resection was achieved in 21 cases. All patients were followed up for 10-206 months after surgery. Twenty-six patients experienced tumor recurrence, and the median PFS was 48.0 months. The 1-year, 3-year, and 5-year PFS was 87.5%, 59.8%, and 41.8%, respectively. Twelve patients died of tumor recurrence, and the median OS was not available. The 1-year, 3-year, and 5-year OS was 98.2%, 91.3%, and 65.8%, respectively. Univariate analysis showed that total tumor removal was significantly associated with a better prognosis. Multivariate analysis confirmed only Simpson grade III and IV resection as an independent risk factor for shorter PFS. Radiotherapy mildly improved PFS after both gross total resection and subtotal resection, showing no significant difference because of the small sample size and short follow-up duration.

CONCLUSIONS

CCM is a rare subtype of World Health Organization grade II meningioma. CCM typically involves young patients and shows a female predilection and high recurrence rate. When possible, total resection is the primary and most suitable treatment for CCM. For patients with primary tumors, radiotherapy is recommended after the initial operation regardless of the extent of resection. For patients with disease recurrence, secondary surgery combined with radiotherapy might serve as an effective treatment.

Intraparenchymal Atypical Meningioma in Basal Ganglia Region in a Child: Case Report and Literature Review

Intraparenchymal meningiomas without dural attachment are extremely rare, especially when they occur in basal ganglia region in child. An 8-year-old boy was admitted at our hospital, complaining of recurrent headache and vomiting for 3 months. Neurological examination showed impaired vision and mild paresis of the left extremities. Magnetic resonance imaging demonstrated a lesion located in the right basal ganglia region extending to superasellar cistern with solid, multiple cystic and necrotic components. Computed tomography revealed calcification within the mass. Due to the anterior cerebral artery involvement, a subtotal resection was achieved and postoperative radiotherapy was recommended. Histopathological examination indicated that the lesion was an atypical meningioma. The postoperative rehabilitation was uneventful. Mildly impaired vision and motor weakness of left extremities improved significantly and the patient returned to normal life after surgery. To our knowledge, intraparenchymal atypical meningioma in basal ganglia extending to superasellar cistern was never reported. The significance in differential diagnosis of lesions in basal ganglia should be emphasized.

Sporadic pediatric meningiomas: a neuroradiological and neuropathological study of 15 cases

OBJECTIVE Sporadic meningiomas have been classified in many different ways. Radiographically, these lesions can be described as occurring in either typical or atypical locations. The purpose of this study was to determine if there are any histopathological differences between sporadic meningiomas that arise in these varying locations in children. METHODS The neuroimaging, histopathological findings, and clinical records in patients with sporadic pediatric meningiomas not associated with neurofibromatosis Type 2 or prior radiation therapy were retrospectively reviewed. Tumors were classified by radiological findings as either typical or atypical, and they were categorized histopathologically by using the latest WHO nomenclature and grading criteria. RESULTS Fifteen sporadic meningiomas in pediatric patients were biopsied or resected at the authors' institution between 1989 and 2013. Five (33%) were typical in radiographic appearance and/or location and 10 (67%) were atypical. Four (80%) typical meningiomas were WHO Grade I tumors. Most (60%) of the atypical meningiomas were WHO Grade II or III. CONCLUSIONS This study is the largest series of sporadic pediatric meningiomas in atypical locations to date. Although sporadic meningiomas are relatively infrequent in children, those with atypical imaging, specifically those with apparently intraparenchymal and intraosseous locations, may be more common than previously recognized. In this study, pediatric sporadic meningiomas arising in atypical locations, in particular intraparenchymal meningiomas, may be of higher histopathological grade. The authors' findings should alert clinicians to the potential for more aggressive clinical behavior in these tumors.

Loss of SMARCE1 expression is a specific diagnostic marker of clear cell meningioma: a comprehensive immunophenotypical and molecular analysis

Clear cell meningioma (CCM) is a rare grade II histopathological subtype that usually occurs in young patients and displays high recurrence rate. Germline SMARCE1 mutations have been described in hereditary forms of this disease and more recently in small syndromic and sporadic CCM series. The diagnostic value of SMARCE1 in distinguishing between CCM and other meningioma variants has not been yet established. The aim of our study was to investigate the status of SMARCE1 in a series of CCMs and its morphological mimickers. We compared the performance of an anti-SMARCE1 antibody and the molecular analysis of the SMARCE1 gene in a retrospective multicenter series of CCMs. All CCMs lossed SMARCE1 immunoexpression. Bi-allelic inactivating events were found by NGS-based sequencing in all of these cases, except for one, which was incompletely explored, but had a wild-type sequence. We then validated the anti-SMARCE1 antibody specificity by analyzing additional 305 pediatric and adult meningiomas of various subtypes and 15 non-meningioma clear cell tumors by SMARCE1 immunohistochemistry. A nuclear immunostaining was preserved in all other meningioma variants, as well as non-meningioma clear cell tumors. In conclusion, our series showed, for the first time, that SMARCE1 immunostaining is a highly sensitive biomarker for CCM, useful as a routine diagnostic biomarker.

Pediatric intracranial clear cell meningioma: a clinicopathological study of seven cases and literature review

BACKGROUND

In this study, we reported seven cases of pediatric intracranial clear cell meningiomas (CCMs) in our institution and reviewed the relevant literature to investigate the clinicopathological characteristics, treatment options, and prognosis of these rare tumors.

METHODS

From January 2005 to June 2016, we retrospectively reviewed seven pediatric intracranial CCMs in terms of their clinical data, preoperative MRI features, and prognosis. Moreover, a critical review of the English language literature was also conducted.

RESULTS

The patients consisted of two males and five females with a median age of 10.5 years (range 6-15 years) at initial surgery. Petroclival and cerebellopontine angle area was the most common location site (5/7). Accordingly, the most common initial manifestation was hearing loss (3/7), and the mean interval from onset of symptoms to admission was 6.8 months (1.5-24 months). Gross total resection was achieved in five patients. Of the six tumors with immunohistochemical records, MIB-1 labeling index varied from 3 to 20 % (mean 8.1 %). During the follow-up period (mean 76.9 months, range 16-180 months), four patients had experienced tumor recurrences and three patients died due to recurrences.

CONCLUSIONS

Pediatric intracranial CCMs have a tendency to recur. There is a significant relationship between MIB-1 labeling index and recurrence. Gross total resection is recommended; if not available, adjuvant radiotherapy should be used to reduce the recurrent rate. In addition, postoperative MRI follow-up should be monitored at an interval time after resection.

Clear-cell meningioma presenting as an infiltrative external auditory canal mass

We present a case of clear-cell meningioma occurring in a 72-year-old female presenting with an infiltrative external auditory canal mass (with both intracranial and extracranial extension and extensive leptomeningeal involvement) and facial nerve paralysis.

A five year-old child with clear cell petro-clival meningioma: case report with clinical and histopathological long-term follow-up

BACKGROUND

Only a few cases have been previously published about clear cell meningiomas in children, the majority of them in the location of the spine. We describe an unusual case of clear cell meningioma occurring at the petro-clival region in a 5-year-old child. We further seek to determine the impact of several growth factors as well as the AKT1 mutation on the tumor growth pattern.

CASE PRESENTATION

A five-year-old girl was presented with a one-week history of cephalgia, ataxia, and left sided torticollis. Magnetic resonance imaging (MRI) revealed a dumbbell-shaped homogeneously petro-clival gadolinium-enhancing mass. A staged operative approach was chosen, and a complete removal of the tumor was achieved. Due to recurrent tumor progression, the child underwent several tumor surgeries and two cranial radiations. None of the treatments were able to stop tumor progression. Consequently, the child died at the age of 14 after further extensive intracranial and extracranial tumor progression. The initial histological examination revealed a clear cell meningioma WHO grade II with an MIB-1 labeling index of <1%, which gradually increased with every recurrence up to 10% by the last progression at the age of 13 years. Analogically, an increasing overexpression of epidermal growth factor receptor (EGFR), the platelet-derived growth factor receptor (PDGFR), and the vascular endothelial growth factor receptor (VEGFR) was observed with each recurrence. The AKT1 (E17K) mutation in the tumor was not detectable in all investigated specimens.

CONCLUSION

Pediatric clear cell meningiomas WHO grade II are very rare. Our data demonstrate the progressive overexpression of EGF-, PDGF-, and VEGF-receptors in each recurrence, providing one of these receptors as targeted therapy in such cases. Further evaluation of these growth factors in clear cell meningioma is required to establish the optimal treatment of these aggressive tumors.

Pediatric intracranial clear cell meningioma associated with a germline mutation of SMARCE1: a novel case

PURPOSE

Intracranial clear cell meningioma (CCM) represents a rare and potentially more aggressive subgroup of meningioma that is observed more frequently in children and adolescents. Despite its characterization as a histological entity, there is little evidence identifying tumorigenic etiologies. Recently, a novel mutation in SMARCE1, encoding a subunit of the SWI/SNF chromatin remodeling complex, was identified in a cohort of spinal CCMs. To date, no intracranial CCM has been subjected to analysis.

METHODS

We report the case of an isolated intracranial CCM in a 14-year-old girl. Gross total resection was achieved following a two-stage approach with no evidence of tumor recurrence 8 months following presentation.

RESULTS

Exon sequencing identified a germline mutation in SMARCE1, which was also present in tumor DNA. Extensive literature review confirmed our study is the first to seek and report a genetic anomaly for childhood intracranial CCMs outside of the NF2 gene locus, and the first to make an association between a germline SMARCE1 mutation and childhood intracranial CCMs.

CONCLUSIONS

Together with the previous description of SMARCE1 mutations in spinal CCMs, our report suggests that SMARCE1 aberrations may be implicated in establishing a clear cell histology irrespective of meningioma location. We would advocate that, where feasible, genetic sequencing is performed on future new cases of childhood neuraxial CCMs and includes interrogation of the SMARCE1 gene.

Intraparenchymal meningioma mimicking cavernous malformation: a case report and review of the literature

Introduction

A primary intraparenchymal meningioma located in the subcortical region of the brain without a dural attachment is extremely rare. To the best of our knowledge, this is the first report showing that meningioma can mimic cavernous malformations.

Case presentation

We present the case of a 42-year-old German man who presented to our institution with seizure. Both computed tomography and magnetic resonance imaging scans showed characters of an intra-axial subcortical lesion with a ‘popcorn’ appearance and hemosiderin deposits in the right parietal lobe. The initial diagnosis was cavernous malformation. Intraoperatively, the lesion presented as a subcortical mass that had no connection to the dura or the ventricle. The histological diagnosis showed a WHO Grade 1 ‘raddled’ psammomatous meningioma with extensive metaplastic ossification. A literature review of 29 cases of intraparenchymal meningiomas regarding their clinical presentations, location and management was performed.

Conclusions

Meningiomas can be found in any region of the brain with and without dural attachment. Intraparenchymal meningiomas can have multiple entities mimicking their presentation. Caution must be used regarding the preoperative differential diagnosis.

Intracranial clear cell meningioma in two children with blood relations: two case reports and literature review

Intracranial clear cell meningioma (CCM) is very rare and often has an aggressive clinical course. The predilection site of intracranial CCM in children was cerebellopontine angle where represents challenging tumor resection because of the vicinity of brainstem, vertebral artery, and lower cranial nerve. Therefore, special consideration is required for this tumor.We report two cases with intracranial CCM in a family and reviewed the literature concerning pediatric intracranial CCM. Case 1 is a 4-year-old boy with a tumor at the right posterior fossa. Case 2 is an 8-year-old boy with a left basilar region tumor. Gross total resection and subtotal resection was achieved in case 1 and case 2, respectively. Case 1 had no tumor recurrence at 12 months after the operation. Case 2 received cyber-knife radiosurgery (CKS) after subtotal resection at 4 months, and the residual tumor had gradually shrunk. Comprehensive chromosomal number aberrations in both patients were revealed by array-comparative genomic hybridization, and loss of neurofibromatosis 2 (NF2) gene was the common genetic abnormality in the two patients.To the best of our knowledge, this is the first report concerned two patients with CCM in a family, and the findings in this article suggest that CKS is a safe and effective adjuvant therapy for residual CCM after operation and NF2 gene mutation plays a role in tumorigenesis of pediatric intracranial CCM.

Intraparenchymal papillary meningioma of brainstem: case report and literature review

Both intraparenchymal papillary meningioma and papillary meningioma with cyst formation of brainstem have never been reported. The authors present an extremely rare case of patient with intraparenchymal papillary meningioma of brainstem. A 23-year-old Chinese male presented with a 4-month history of progressive left upper limb and facial nerve palsy. Magnetic resonance imaging revealed a cystic-solid, heterogeneously enhancing mass in pons and right cerebral peduncle with no dural attachment. The tumor was totally removed via subtemporal approach. During surgery, the lesion was found to be completely intraparenchymal. Histological and immunohistochemical examinations were compatible with the diagnosis of papillary meningioma. The lesion recurred nine months after primary surgery, a second surgery followed by radiotherapy was performed. Till to now (nearly 2 years after the treatment), the patient is tumor free survival. Intraparenchymal meningioma of brainstem with cystic formation is very rare, however, it should be considered as a differential diagnosis of a brainstem neoplasm. The present case strongly recommended that postoperative radiotherapy was essential for the patients with papillary meningiomas.

Intracranial clear cell meningioma: a clinicopathologic study of 15 cases

OBJECT

Clear cell meningioma (CCM) is a rare histological variant of meningioma. CCM has a high recurrence rate and aggressiveness. In this study, we reviewed our experience in the treatment of the lesion.

METHODS

Here we present a series of 15 patients with intracranial CCM. The clinical data were retrieved from the records of our Neurosurgery Department and the patients' prognoses were attained by clinic service and telephone. Immunohistochemistry for epithelial membrane antigen (EMA), vimentin, glial fibrillary acidic protein (GFAP), CD10, and S-100 was done, and the MIB-1 labeling index was calculated in all cases.

RESULTS

The 15 patients included eight males and seven females; the mean age was 34.8 years. The most frequent initial symptoms were headache and hearing loss. The most common location was the cerebellopontine angle (CPA) zone. Eleven patients had total removal and four patients underwent subtotal removal. Histological features of atypia were present in different proportions, from 6.7% to 100%, and six cases accorded with atypia. Three tumors showed brain invasion. EMA and vimentin were 100% positive, and CD10 was 100% negative. GFAP was 87% negative and S-100 was 93% negative. The mean follow-up period was 36.7 months. Three patients with brain invasion all recurred and five cases with atypia recurred. In 11 patients with total removal, six patients recurred. In four patients with subtotal removal, three patients recurred. Kaplan-Maier analysis showed that incomplete surgical resection was significantly associated with recurrence (p = 0.001). The MIB-1 labeling index for recurrence was 5.7 ± 2.7% versus 2.8 ± 1.5% for no recurrence (p = 0.036).

CONCLUSIONS

CCM is a rare subtype of meningioma, with a tendency to present in younger patients and a propensity to recur. Immunohistochemistry plays a vital role in differentiating CCM from other tumors. Brain invasion, atypia and MIB-1 labeling index are likely to predict the recurrence. The extent of resection might be connected with the prognosis.

Supratentorial clear cell meningioma in a child: A rare tumor at unusual location

Clear cell meningioma is a rare subtype of meningioma seen mainly in pediatric patients. Supratentorial location is an unusual site of occurrence and its natural history and prognosis are not well described in the literature. We present a unique case of a left-sided frontoparietal tumor in a 15-year-old child who was managed successfully with gross total surgical excision and is recurrence-free at 18 months follow-up. A favorable clinical behavior and a longer symptom-free interval can be expected after gross total removal. The patients should be followed after successful surgery and other modalities of therapy should be used for recurrence.

Clear Cell Meningiomas

BACKGROUND AND IMPORTANCE

Intracranial clear cell meningioma is very rare. We present 3 cases of intracranial clear cell meningiomas genetically characterized by comparative genomic hybridization with a review of the literature.

CLINICAL PRESENTATION

Patient 1 is a 38-year-old woman with a petroclival tumor. Patient 2 is a 60-year-old man with a tumor at the foramen magnum. Patient 3 is a 60-year-old man with a tumor at the posterior clinoid process. Gross total resection was performed in patients 1 and 2. Patient 1 has been free from recurrence for 10 years. Patient 2 had a tumor recurrence at 14 months after the operation. After partial resection, conventional radiotherapy was given, and there was no tumor regrowth at 2 years after radiotherapy. Subtotal resection was performed in patient 3, and no regrowth was detected for 3 months. Histologically, all tumors were composed of cells with clear cytoplasm reactive for periodic acid–Schiff and diagnosed as clear cell meningioma. The MIB-1 and p53 staining indexes were 1.8, 1.7, and 5.6 and 1.1, 1.0, and 5.5, respectively. Comparative genomic hybridization revealed no chromosomal number aberrations in patient 1, numerous losses and gains including loss of chromosome 1 in patient 2, and loss of only 22q in patient 3. Because staining indexes of MIB-1 and p53 were equivalent in 2 patient (patients 1 and 2) with a long follow-up period, the contrary clinical courses are likely associated with genetic characteristics.

CONCLUSION

To the best of our knowledge, this is the first report that suggests association between tumor behavior and genetic characteristics in clear cell meningiomas.

Clear cell meningioma of the fourth ventricle in a child: a case report and literature review

Clear cell meningiomas are rare meningioma variants and are recognized as World Health Organization grade II tumours. They may be difficult to manage given their propensity to recur early especially if present in surgically challenging locations. We describe a rare case of a fourth ventricular clear cell meningioma without dural attachment in a 14-year-old boy with an unusual presentation of failure to thrive. The case is presented in detail and a review of the recent literature is discussed.

Intracranial clear-cell meningioma

Intracranial clear-cell meningioma (CCM) is rarely reported in the literature since it has to be distinguished from other subtypes of meningioma. Most of the CCMs are intraspinal, according to the related literature. We report a case of occipital parietal CCM in a 6-year-old child, review all the 35 intracranial CCMs that have been reported since 1995 to present and discuss their clinical, radiological and histopathologic characteristics.

Primary clear cell meningioma of the orbit mimicking a metastatic carcinoma: usefulness of immunohistochemistry and cytogenetic analysis

Clear cell meningiomas (CCM) are rare tumors of the nervous system that usually occur in young patients and display high recurrence rates and potentially aggressive behavior. In this report, we describe a primary CCM of the orbit in an 84-year-old man with a previous history of a clear cell carcinoma of the kidney. Histologically, the tumor demonstrated a sheet-like proliferation of clear polygonal cells. Differential diagnosis includes metastasis of clear cell carcinomas. Immunohistochemistry, by showing that tumor cells expressed vimentin, epithelial membrane antigen, and progesterone antigens, and cytogenetic analysis, by identifying a monosomy 22, confirmed the diagnosis of CCM.

Atypical growth pattern of a meningioma in an adult

A 49-year-old woman presented with a rare atypical growth pattern of meningioma without evidence of dural attachment manifesting as chronic headache associated with transient paresthesia and left motor disorders. On admission, neurological examination showed no abnormalities. Magnetic resonance (MR) imaging revealed a right temporo-parieto-occipital lesion, which appeared to involve the subdural space and filling the cortical sulci. The lesion caused peritumoral white matter edema. The tumor appeared hypointense on T(1)-weighted and hyperintense on T(2)-weighted MR images, with homogeneous enhancement after contrast administration. A biopsy of the lesion was performed. Histological examination indicated that the lesion was a meningioma. Intraparenchymal meningiomas should be considered in the differential diagnosis of intraaxial lesions in patients of any age.

Clear cell meningioma, an uncommon variant of meningioma: a clinicopathologic study of nine cases

AIMS

Clear cell meningioma (CCM) is an uncommon variant of meningioma, which affect younger patients, occur more often in spinal or cerebello pontine locations and shows a higher recurrence rate. Only few case reports have been described in the literature. The study has been undertaken to document the clinicopathological features of nine cases of CCM, operated at All India Institute of Medical Sciences during 1998 to December 2005.

METHODS

Clinical information was retrieved from the records of our Neurosurgery Department. The cases were stained with H&E, periodic Acid Schiff (PAS) with and without diastase. Immunohistochemistry for pancytokeratin, epithelial membrane antigen, vimentin, glial fibrillary acidic protein, and MIB-1 was done in all cases.

RESULTS

During a period of 8 years, nine cases of CCM were diagnosed. Age ranged from 10 to 65 years (median age 26.0 years) with female predominance. Most common location was posterior fossa (CP angle). Clinically most of the patients presented with history of headache and features of cranial nerve palsies. The duration of symptoms varied from 3 to 60 months (mean 16.7 and median of 4 months). Radiologically lesions showed homogenous enhancement and were isointense to brain parenchyma. Histopathologic examination revealed tumor cells to be arranged in sheets with clear cytoplasm and monomorphic nuclei. MIB-1 labeling index (LI) ranged from 2 to 12% with a mean of 9%. Follow up varied from 3 to 84 months (median 36 months) and recurrence was noted in two patients after 2 and 3 years of surgery, respectively, despite their low MIB-1 labeling indices.

CONCLUSIONS

CCM is a rare variant of meningioma with poor outcome. Less than 50 cases have been described in the literature. Low rate of recurrence and recurrence despite their low MIB-1 LI are some of the features, which needs to be documented. Hence, larger number of cases with adequate follow-up data need to be studied further to establish the clinical significance of this variant.

Meningeal tumors of childhood and infancy. An update and literature review

Meningeal derived tumors of the first 2 decades of life are often diagnostically challenging due to the wide morphologic spectrum encountered and the rarity of most individual entities. The 2 most common patterns include the dural/leptomeningeal-based mass and neoplastic meningitis. Both primary and secondary meningeal presentations may occur, either early or late in the course of various meningothelial, mesenchymal, embryonal, glial, hematopoietic, histiocytic, melanocytic, and inflammatory tumors. As in other areas of pediatric pathology, there are significant differences between this patient cohort and adults, differences which will be emphasized in this review.

Intracranial meningiomas in children: report of 27 new cases and critical analysis of 440 cases reported in the literature

We accumulated 440 cases of intracranial meningiomas in patients under 16 years of age, and another 27 personal. This review confirms the existence of specific clinical features of spontaneous and radiation-induced meningioma in children. In addition, we discuss various points that suggest a more aggressive behavior of meningiomas in children than in adults. (J Child Neurol 2006;21:31-36).

Spinal intradural clear cell meningioma following resection of a suprasellar clear cell meningioma. Case report and recommendations for management

The authors report on 32-year-old woman with a history of a previously resected suprasellar clear cell meningioma (CCM), who returned to their institution after 3 years suffering from progressively worsening leg and back pain associated with leg weakness and bowel and bladder dysfunction. A magnetic resonance image of the thoracic and lumbar spine demonstrated a homogeneously enhancing intradural mass that filled and expanded the thecal sac. The patient underwent multiple-level laminectomies for resection of the lesion. Results of pathological studies confirmed distant recurrence of a CCM. Since its initial recognition as a rare but aggressive histological variant of meningothelial tumors, the body of literature on CCMs has grown to include more than 40 cases. Nevertheless, the natural history of this neoplastic entity remains ill defined, as are the recommendations for management. Of particular concern is the treatment of patients who have undergone subtotal resection or present with recurrence. To the authors' knowledge, the present case represents the sixth distant recurrence of CCM reported in the literature. The radiographic and histological studies are reviewed along with the current literature on this subtype of meningioma. Recommendations for surveillance and treatment are made.

Intraparenchymal meningioma

A 54 year-old woman presented with severe headache. Neuroimaging showed an enhancing intra-axial mass in the right superior temporal region associated with severe peritumoral oedema. Preliminary diagnosis was cerebral metastasis. The mass was surgically removed. Histopathology and immunohistochemistry showed the mass to be an intraparenchymal meningioma, which is rare. The relevant literature is reviewed.

Clear cell meningioma: case report and review of the literature

Clear cell meningioma (CCM) is a rare variant of meningioma. Only 17 cases have been previously reported in children. Although it has bland cytologic features, it has a higher rate of recurrence than does conventional meningioma. This variant has been reported in sites such as spinal/intradural (lumbar and thoracic), cerebellopontine angle, and supratentorial. The differential diagnosis of CCM includes microcystic meningioma, hemangioblastoma, and clear cell ependymoma. The characteristic histology and immunohistochemistry leads to the diagnosis. We present a case of a 7-year-old boy with a CCM of the cauda equina and a review of pediatric CCM.

Insights into meningioangiomatosis with and without meningioma: a clinicopathologic and genetic series of 24 cases with review of the literature

Meningioangiomatosis (MA) is a rare seizure-associated lesion of presumed hamartomatous or developmental origin. It is occasionally combined with a neoplasm, most commonly meningioma (MA-M). In the current study, we examined 24 cases (14 pure MA, 10 MA-M) using immunohistochemistry for merlin, protein 4.1 B, progesterone receptor (PR), and MIB-1, as well as FISH for NF2 and 4.1B gene dosages. Nine cases of MA-M (90%) had gene deletions (NF2/4.7B), protein losses (merlin/protein 4.1B), and/or PR positivity, with a similar or identical phenotype in both components. No PR positivity or gene deletions were seen in pure MAs, though merlin and/or protein 4.1B were immunonegative in six cases. Our data suggest that in most MA-Ms, the MA component is neoplastic, likely representing an exuberant perivascular pattern of spread from the meningioma, rather than an underlying hamartoma. This pattern of spread may be facilitated by meningiomas that are predominantly leptomeningeal or intracerebral in origin. It remains important to distinguish this pattern from true brain invasion, given the more ominous prognostic significance of the latter. In contrast, most perivascular spindled cells of pure MA are genetically and immunohistochemically similar to non-neoplastic meningothelial cells, consistent with current histogenetic theories.

Two cases of nondura-based clear cell meningioma of the cauda equina

Clear cell meningioma is a rare disorder. We report two cases of nondura-based clear cell meningioma of the cauda equina, one in a 24-year-old male and the other in a 19-year-old female. Both patients had complained of numbness and spontaneous pain in the lower back and limbs for several months. Magnetic resonance imaging and computed tomography scanning revealed an intradural tumor in the cauda equina in each case. At surgery, a neurilemoma was suspected, because each of the tumors had displaced nerve roots and had attached to one of the nerve roots without any adherence to the dura. Light microscopy revealed that both tumors were well-demarcated with a thin capsule and consisted mainly of clear, glycogen-rich, polygonal cells with vague whorl formations, and of copious deposits of hyalinized blocky collagen in the stroma and perivascular areas. The neoplastic cells were immunopositive for vimentin and epithelial membrane antigen, but immunonegative for S-100 protein and chromogranin A. Positive nuclei for MIB-1 were very few in both cases, and PCNA-labeling indices were 12.1% and 24.7%, respectively. No local recurrence has been seen for 61 months and for 52 months, respectively.

Clear cell meningioma: case report and literature review

The clear cell meningioma is rare and a recently described histologic variant of meningioma. The most interesting aspect of clear cell meningioma is the high recurrence rate and agressiveness. Until now 17 intracranial clear cell meningioma cases had been reported in the English language literature. We present 2 new cases of clear cell meningioma which is discussed with the relevant literature.

Clear cell meningioma of the fourth ventricle

Clear cell meningioma (CCM) has been identified and included in the World Health Organization classification of CNS tumors recently. CCMs are histologically characterized by sheets of polygonal cells with clear cytoplasm, which is the expression of high glycogen concentration. Compared with other variants of meningiomas, CCMs occur in younger patients and usually are located in the spinal canal and posterior fossa, the last ones mainly in the cerebellopontine angle. Some reports suggest that CCMs have high recurrence rate and potentially aggressive behavior. Poor outcome has been shown in intracranial and spinal tumor location, but indicators that predict outcome have not been established. The authors present two cases of intracranial CCMs, with excellent outcome in patients harboring tumor location (restricted to the fourth ventricle) and some clinical particular features (young age, gender, obesity, and moderate impairment of intellectual capacity). To the best of our knowledge, these are the two first reported cases of clear cell meningioma located primarily in the fourth ventricle.

Meningiomas múltiplos em um lactente: relato de caso e revisão da literatura

Neste trabalho é apresentado um caso de meningiomas múltiplos em um lactente de cinco meses de idade, em que o diagnóstico se torna difícil pela apresentação da lesão dominante, de localização selar e supra-selar, com grande área cística na região frontal direita, e que tem grande interesse por sua raridade. Em seguida é apresentada uma revisão da literatura sobre o assunto.

Clear-cell meningioma in a 22-month-old male: a case report and literature review

We report a case of spinal clear-cell meningioma occurring in a 22-month-old male who presented a right limp and then refused to walk. Spinal magnetic resonance imaging demonstrated a large, intradural tumor from T(11) to L(4), which was totally excised. The patient's postoperative recovery was uneventful and 5 months after surgery he began walking again. The latest follow-up magnetic resonance imaging of the brain and spine, obtained 42 months after diagnosis, was negative for tumor recurrence. Though clear-cell meningioma is a rare form of meningioma, it should be considered in the differential diagnosis of any space-occupying lesion of the spine arising in very young children. Complete surgical removal is necessary because it is potentially aggressive and may recur. After surgery, an accurate follow-up is warranted.

Intraspinal familial clear cell meningioma in a mother and child. Case report

The authors present a case of familial clear cell meningioma in which the proband is a child with an intraspinal tumor. The clear cell meningioma variant has recently been studied. The literature regarding clear cell meningioma is reviewed.

Meningiomas in childhood

Meningiomas are rare intracranial neoplasms in the pediatric population. Most of the reports concerning these tumors have stressed some distinguishing features comparable with the adult counterpart. Besides the lower incidence, the nearly equal sex distribution, the relatively common infratentorial location and the frequent development within the ventricular system have been emphasized. A poor prognosis of pediatric meningiomas has also been claimed by authors who have suggested that this could be owing to a possibly more aggressive behavior, accounting for the huge size that these tumors have usually reached at diagnosis, the difficult surgical excision, and the higher recurrence rate. The analysis of recent series challenges the concept that pediatric meningiomas do actually bear a worse prognosis than similar tumors occurring in older patients. Improved surgical techniques have in fact resulted in higher percentages of complete tumor removal. Better histological delineation has allowed the identification of highly aggressive meningeal neoplasms, which in the past were not differentiated properly, thus contributing to the apparent higher incidence of recurrent tumors in the pediatric population. When the studies are limited to the "classical" form of meningioma, it becomes apparent that pediatric meningiomas do not behave more aggressively than meningiomas in adult patients.