Primary intraosseous meningioma

Case report of a patient with an intraosseous meningioma presenting as possible metastasis from prostate cancer: Diagnostic dilemma and review of literature

Intraosseous meningiomas are a rare subtype of meningiomas representing approximately 2% of all cases. They can confound a diagnosis of other bone lesions including metastatic tumors. We present a case of a patient with prostate cancer who on staging workup was suspected to have a skull metastasis. Both bone scan and CT Head demonstrated a lesion in the right frontal calvarium. Surgical resection and pathology revealed an intraosseous meningioma. The patient was restaged as having localized prostate cancer and the was offered curative treatment for his malignancy. The case highlights the importance of obtaining tissue diagnosis in cases of radiographic isolated oligometastatic disease in patients with a known primary malignancy.

Primary intraosseous meningioma: a case of early symptomatic calvarial origin meningioma

Primary intraosseous meningiomas are rare extradural tumors. They are typically slow-growing, painless, and asymptomatic until they cause a mass effect. We report a case of a calvarial primary intraosseous meningioma, which became symptomatic despite a very small size. A 67-year-old female with a history of precancerous breast tissue presented with right-sided stroke-like symptoms. Computed tomography showed right parietal convexity irregularity without hemorrhage or infarct. MRI indicated a right parietal calvarial signal abnormality and dural thickening, suggesting metastases or primary osseous neoplasm. A PET scan revealed heterogeneous uptake in the right parietal skull with no other abnormalities. Histology confirmed the diagnosis of primary intraosseous meningioma. Histopathological examination is crucial to avoid misdiagnosis and treatment planning, which may involve wide-margin skull resection, radiation, or both.

CSF or middle ear effusion? Diagnostical dilemmas in a patient with temporal bone meningioma: A case report

Introduction

Cerebrospinal fluid (CSF) fistulas are a rare phenomenon, that can lead to life-threatening complications if left untreated. Presenting as rhinorrhea or otorrhea, they can be difficult to diagnose due to admixture of other bodily fluids. Typically, CSF fistulas develop after trauma, but in rare instances, they can be diagnosed in patients with a neoplastic lesion.

Objective

To discuss several steps in diagnosing CSF fistulas.

Patient

A fifty-year-old female with an intra-osseous temporal bone meningioma.

Interventions

For diagnosing CSF admixture in fluids, two tests are looked into: beta-2 transferrin (β2T) and beta-trace protein (βTP) testing.

Conclusion

Testing for βTP is a highly sensitive, quick and non-invasive method to assess CSF admixture in middle ear effusion. Because of its lower cost, faster results and easy sample collection, βTP testing has in our clinic replaced β2T testing. The current case illustrates a rare etiology of a CSF fistula, where β2T testing presumably showed false-negative results and βTP testing showed true-positive results.

Virtual Surgical Planning and Customized CAD/CAM Cranial Implants: Preoperative and Intraoperative Strategies for Temporal Intraosseous Meningioma Resection

Primary intraosseous meningioma (PIM) is a rare subtype of extradural meningiomas, with the indication for surgical resection in most cases. With an increasing demand for efficient workflows with optimal functional and cosmetical results, techniques for bone reconstruction after resection are developing rapidly. The authors present 2 cases with one-stage cranioplasty after resection of PIM, using 3D technology for preplanned patient-specific implants. In the first case, a premanufactured patient-specific PEEK implant was used for reconstruction; in the second case, a 3-dimensional (3D)-based premanufactured silicon mold was used to produce a customized PMMA implant intraoperatively. Both techniques enabled the surgeons to achieve optimal intraoperative fit of the implant after craniectomy, leading to satisfying functional and cosmetic results. The use of 3D technology, such as Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) for the production of patient-specific implants can optimize 1-stage cranioplasty after PIM resection.

A Case of Recurrence of Benign Convexity Primary Intraosseous Meningioma

Meningiomas originating within the bones of the skull are rare and have been reported as primary intraosseous meningiomas (PIOM). Moreover, PIOMs with a skull base location or malignant pathology are predisposed to recurrence; however, recurrence is quite rare among PIOMs characterized by a convexity location and benign pathology. Here, we present a case of extensive recurrence of a convex intraosseous meningioma with benign pathology. A 72-year-old woman presented with a headache to our hospital. Gd contrast-enhanced magnetic resonance imaging revealed an enhanced tumor in the left frontal to the parietal region extending through the calvarial bone and invading the subdural space and subcutaneous tissue. Skull radiograph and computed tomography identified a remarkable osteolytic change in the lesion. Macroscopic complete resection (MCR) of the tumor and the surrounding tissues was performed. The tumor was histopathologically diagnosed as a transitional meningioma (World Health Organization grade 1). Seven years after the surgery, the patient presented with dysarthria, and the recurrence of the tumor was identified as massive lesions extending through the calvarial bone to the orbital bone, partially protruding into the brain and scalp. MCR was performed again, with the reconstruction of the skull for an extensive calvarial area using a titanium plate. This case is unique due to the extensiveness of the recurrent tumor and its rarity. Here, we report the details of the clinical course and discuss the characteristics of this case.

Imaging Features of Primary Intraosseous Meningiomas

OBJECTIVE

To describe the imaging features of primary intraosseous meningiomas (PIMs) to aid an accurate diagnosis.

METHODS

Clinical materials and radiological data for 9 patients with pathologically confirmed PIMs were reviewed comprehensively.

RESULTS

Most lesions involved inner and outer plates of the calvaria and all were relatively well circumscribed. Upon computed tomography, portions of the solid neoplasm were hyperattenuated or isoattenuated. Hyperostosis was found in many lesions, but calcification was seen rarely. On magnetic resonance imaging, most neoplasms were hypointense on T1-weighted images, hyperintense on T2-weighted images, and heterogeneous on fluid-attenuated inversion recovery images. In most cases, the soft tissue of neoplasms showed hyperintense on diffusion-weighted imaging and hypointense on apparent diffusion coefficient. All lesions were obviously enhanced after gadolinium administration. Each patient accepted surgical treatment and recurrence was not observed during follow-up.

CONCLUSIONS

Primary intraosseous meningiomas are very rare tumors that occur usually in later life. They are well-defined and tend to involve the inner and outer plates of the calvaria, with a classic appearance of hyperostosis on computed tomography. Primary intraosseous meningiomas display hypointense on T1-weighted images, hyperintense on T2-weighted images, and hyperattenuated or isoattenuated on computed tomography. Hyperintense on diffusion-weighted imaging, hypointense on apparent diffusion coefficient can also be found. Obvious enhancement supplied additional information for an accurate diagnosis. A neoplasm with these features should raise the suspicion of a PIM.

Surgical Resection of Large Primary Intraosseous Meningiomas (6 Case Reports)

OBJECTIVE

The clinical features and surgical techniques related to patients undergoing resection of extracranial large primary intraosseous meningiomas are studied.

METHODS

The clinical characteristics, treatment, and prognosis of 6 patients with primary intraosseous meningiomas larger than 5 cm in diameter were retrospectively reviewed in the 10th Neurosurgical Department of Beijing Tiantan Hospital, Capital Medical University.

RESULTS

Five males and one female (18-57 years old) suffered from large primary intraosseous meningiomas. The main symptoms were headaches accompanied by head swelling. CT showed irregular thickening of the bone diploe with increased density and uneven surface. MRI showed partial bone destruction of the skull, local thickening of the internal and external plates, shell and palisade changes of the external cranial plate, and enhancement of the adjacent meninges. A horseshoe or coronary incision plus the "Mercedes-Benz" incision were chosen to expose the skull bone, and drilling was performed in the normal skull bone at the transition zone between abnormal and normal skull bone. After drilling, the sub flap dura was dissected, the hyperplastic skull was dissected with a milling cutter, and the residual tumor was then resected. A cranioplasty was performed 6 months to 1 year later.

CONCLUSIONS

Surgical treatment and precise perioperative management can achieve a better prognosis for large intraosseous meningiomas.

A Primary Intraosseous Meningioma: A Rare Case of Malignancy with High Proliferative Ability

Primary intraosseous meningioma (PIM) is a rare tumor that arises in the skull. Histopathologically, it is generally described as a slow-growing, benign lesion. However, on rare occasions, PIM presents as a malignancy with high proliferative ability, which requires maximal resection, adjuvant radiotherapy, and subsequent careful follow-up. Because of the rarity of such cases, they present a diagnostic challenge with unusual pathological findings. Herein, we report a case of a primary intraosseous anaplastic meningioma with extensive invasion inside and outside the skull, along with the results of whole-genome analysis. Histopathological diagnosis was a World Health Organization grade 3 anaplastic meningioma. In the literature, only two cases of anaplastic PIM have been reported, so its characteristics and treatment are poorly understood. Our patient was successfully treated with tumor resection, followed by intensity-modulated radiation therapy. Follow-up imaging studies revealed no recurrence or distant metastasis, including to lung, liver, and bone, at 8 months after the surgery.

Uncommon and atypical meningiomas and imaging variants: A report of 7 cases

Meningiomas constitute the most common extra-axial tumor of the central nervous system and can have a wide-ranging manifestation of imaging. There are several types of unusual depictions depicted with the magnetic resonance imaging (MRI) of meningiomas that have been established thus far. It is thus crucial for the reporting radiologist or neurosurgeon to have an in-depth knowledge of their variable manifestations in order to be able to differentiate these neoplasms from the numerous tumors that can mimic their appearance. Meningioma is frequently challenging to diagnose when imaging variants are present. Nevertheless, a number of unusual histological variants have imaging or clinical features which are related to typical meningiomas and, in numerous cases, these require specific surgical management. The present study describes 7 cases of meningiomas, which were either simple atypical, unusual gigantic extracranial intracranial parasagittal, or not visible meningiomas. These uncommon and atypical imaging variants of meningiomas are described herein in an aim to underline their various potential presentations.

Primary intraosseous meningioma with subcutaneous and dural invasion: A case report and literature review

Primary intraosseous meningiomas (PIOMs) are a rare subset of meningiomas, comprising fewer than 1% of all such tumors. Furthermore, PIOMs presenting as osteogenic lesions that invade both the dura and subcutaneous tissue are extremely rare. Unlike intracranial meningiomas, diagnosing and treating PIOMs are challenges due to their insidious clinical behavior and a lack of clear radiological diagnostic criteria. We report the case of a 60-year-old female with headache and a slightly outward protrusion of the parietal region of the skull. CT showed an osteogenic lesion in the right parietal bone. MR imaging indicated mild to moderate homogeneous enhancement with an intense dural reaction. The suggested clinical diagnosis was lymphoma, so we performed a skull biopsy, which revealed an intraosseous benign meningioma. A precise resection strategy was planned with a neuronavigation system accompanied by a one-step customized titanium mesh cranioplasty. The lesion was completely removed, and pathological analysis confirmed a meningothelial meningioma (WHO Grade I) of intraosseous layer origin invading the dura mater and subcutaneous tissue. This case highlights the need for an initial biopsy when the lesion is difficult to diagnose on imaging. Complete resection should be attempted to minimize the risk of recurrence.

Intraosseous meningioma, a rare presentation of a common brain tumor: illustrative case

BACKGROUND

The subset of extradural meningiomas arising from bone is called primary intraosseous meningioma. The present article outlines the clinical presentation, investigation, surgical management, and clinical outcomes of a challenging case of intraosseous meningioma.

OBSERVATIONS

A 27-year-old male presented with new-onset seizure of 3 years' duration and growing painless hard swelling involving the left frontoparietal bone, the medial aspect of the left orbit, the nasal bone, and the temporal bone. Brain computed tomography showed a diffuse intradiploic space osseous lesion with a ground-glass appearance. The patient underwent bifrontal craniotomy and tumor excision. The histopathological sections showed the presence of classic whorls of meningothelial cells around reactive bony tissue suggestive of intraosseous meningioma. Postoperatively, the patient was neurologically intact, and he was discharged in a stable condition. The outcome of this case was satisfactory.

LESSONS

The treatment of primary intraosseous meningioma is wide surgical excision together with the involved dura and any intradural tumor. The location of the tumor determines the approach and the amount of resection, keeping in mind preservation of function. The use of adjuvant therapy is reserved for cases of tumor recurrence or an atypical type.

Bone Invasive Meningioma: Recent Advances and Therapeutic Perspectives

Meningioma is the most common primary neoplasm of the central nervous system (CNS). Generally, these tumors are benign and have a good prognosis. However, treatment can be challenging in cases with aggressive variants and poor prognoses. Among various prognostic factors that have been clinically investigated, bone invasion remains controversial owing to a limited number of assessments. Recent study reported that bone invasion was not associated with WHO grades, progression, or recurrence. Whereas, patients with longer-recurrence tended to have a higher incidence of bone invasion. Furthermore, bone invasion may be a primary preoperative predictor of the extent of surgical resection. Increasing such evidence highlights the potential of translational studies to understand bone invasion as a prognostic factor of meningiomas. Therefore, this mini-review summarizes recent advances in pathophysiology and diagnostic modalities and discusses future research directions and therapeutic strategies for meningiomas with bone invasion.

Fibrous granulation mimicking cranial intraosseous tumor

A cranial intraosseous lesion is a rare disease with a limited number of subtypes. We report a case of a cranial intraosseous fibrous granulation that mimicked an intraosseous tumor. A 57-year-old man was incidentally found to have a cranial intraosseous lesion on brain computed tomography. Total resection was performed to establish a pathological diagnosis and to achieve cosmesis, and the pathological diagnosis was fibrosis and fibrous granulation in the medullary cavity. Fibrous granulation tissue occurs in the calvarium due to bone defects secondary to acquired factors, including trauma. Since its pathological diagnosis is established through surgery, surgery should be carefully considered based on the patient's chief complaint, location of the lesion, and suspicion of malignancy based on imaging findings.

Primary Intraosseous Osteolytic Meningioma with Aggressive Clinical Behaviour: Clinico-Pathologic Correlation and Proposed New Clinical Classification

(1) Introduction: Primary intraosseous osteolytic meningiomas (PIOM) are non-dural-based tumors predominantly presenting an osteolytic component with or without hyperostotic reactions. They are a subset of primary extradural meningiomas (PEM). In this study, we present a peculiar case with a systematic literature review and propose a new classification considering the limitations of previous classification systems. (2) Materials and Methods: Using a systematic search protocol in Google Scholar, PubMed, and Scopus databases, we extracted all case studies on PIOM published from inception to December 2020. A 46-year-old female patient form Dhaka, Bangladesh, was also described. The search protocol was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. (3) Results: Here, we present a 46-year-old female patient with PIOM who successfully underwent bifrontal craniotomy and gross total removal (GTR) of the tumor. At 6-month follow-up, no tumor recurrence was shown. Including our new case, 55 total cases from 47 articles were included in the analysis. PIOMs were in closer frequency among males (56.4%) and females (43.6%). The most common tumor location was the frontal and parietal calvarium, most commonly in the frontal bone (29.1%). Surgical resection was the predominant modality of treatment (87.3%); only 1.8% of patients were treated with radiotherapy, and 5.4% received a combination of surgery and radiotherapy. Gross total resection (GTR) was achieved in 80% of cases. Extracranial extension was reported in 41.8% of cases, dural invasion in 47.3%, and recurrence in 7.3%. Whole-body 68 Ga-DOTATOC PET/CT has also been reported as a useful tool both for differential diagnosis, radiotherapy contouring, and follow-up. Current treatments such as hydroxyurea and bevacizumab have variable success rates. We have also suggested a new classification which would provide a simple common ground for further research in this field. (4) Conclusions: Surgical resection, especially GTR, is the treatment of choice for PIOM, with a high GTR rate and low risk of complications and mortality. More research is needed on the differential diagnosis and specific treatment of PIOM.

Primary intraosseous meningioma of the vertebra: illustrative case

BACKGROUND

Primary intraosseous meningiomas (PIMs) are rare, and PIMs of the vertebrae have not yet been reported. The authors report a case of primary meningioma arising from the vertebrae.

OBSERVATIONS

A 49-year-old man presented with lower back pain and numbness in both lower extremities. Lumbar spine magnetic resonance imaging revealed an L2 pathological fracture with epidural and paraspinal invasion. The patient had undergone a first palliative decompression and fixation surgery, and the diagnosis turned out to be a World Health Organization grade III anaplastic meningioma based on histopathology. The tumor had progressed after first operation and radiation therapy, and the patient was referred to the authors’ institute for excision. The patient had an uneventful postoperative course after a revisional total en bloc spondylectomy of L2.

LESSONS

The authors present a rare case of PIM of the vertebrae with epidural and paraspinal invasion. Careful preoperative assessment and surgical planning is crucial for successful patient management.

Functional and structural analyses of novel Smith-Kingsmore Syndrome-Associated MTOR variants reveal potential new mechanisms and predictors of pathogenicity

Smith-Kingsmore syndrome (SKS) is a rare neurodevelopmental disorder characterized by macrocephaly/megalencephaly, developmental delay, intellectual disability, hypotonia, and seizures. It is caused by dominant missense mutations in MTOR. The pathogenicity of novel variants in MTOR in patients with neurodevelopmental disorders can be difficult to determine and the mechanism by which variants cause disease remains poorly understood. We report 7 patients with SKS with 4 novel MTOR variants and describe their phenotypes. We perform in vitro functional analyses to confirm MTOR activation and interrogate disease mechanisms. We complete structural analyses to understand the 3D properties of pathogenic variants. We examine the accuracy of relative accessible surface area, a quantitative measure of amino acid side-chain accessibility, as a predictor of MTOR variant pathogenicity.

We describe novel clinical features of patients with SKS. We confirm MTOR Complex 1 activation and identify MTOR Complex 2 activation as a new potential mechanism of disease in SKS. We find that pathogenic MTOR variants disproportionately cluster in hotspots in the core of the protein, where they disrupt alpha helix packing due to the insertion of bulky amino acid side chains. We find that relative accessible surface area is significantly lower for SKS-associated variants compared to benign variants. We expand the phenotype of SKS and demonstrate that additional pathways of activation may contribute to disease. Incorporating 3D properties of MTOR variants may help in pathogenicity classification. We hope these findings may contribute to improving the precision of care and therapeutic development for individuals with SKS.

Smith-Kingsmore Syndrome is a rare disease caused by damage in a gene named MTOR that is associated with excessive growth of the head and brain, delays in development and deficits in intellectual functioning. We report 7 patients who have changes in MTOR that have never been reported before. We describe new medical findings in these patients that may be common in Smith-Kingsmore Syndrome more broadly. We then identify how these new gene changes impact the function of the MTOR protein and thus cell function downstream. Lastly, we show that changes in the gene that lie deep inside the 3D structure of the MTOR protein are more likely to cause disease than those changes that lie on the surface of the protein. We may be able to use the 3D properties of MTOR gene changes to predict if future changes we see are likely to cause disease or not.

Imaging Spectrum of Calvarial Abnormalities

Calvarial abnormalities are usually discovered incidentally on radiologic studies or less commonly manifest with symptoms. This narrative review describes the imaging spectrum of the abnormal calvaria. The extent, multiplicity, and other imaging features of calvarial abnormalities can be combined with the clinical information to establish a final diagnosis or at least narrow the differential considerations. Prior trauma (congenital depression, leptomeningeal cysts, posttraumatic osteolysis), surgical intervention (flap osteonecrosis and burr holes), infection, and inflammatory processes (sarcoidosis) can result in focal bone loss, which may also be seen with idiopathic disorders without (bilateral parietal thinning and Gorham disease) or with (Parry-Romberg syndrome) atrophy of the overlying soft tissues. Anatomic variants (arachnoid granulations, venous lakes, parietal foramina) and certain congenital lesions (epidermoid and dermoid cysts, atretic encephalocele, sinus pericranii, and aplasia cutis congenita) manifest as solitary lytic lesions. Other congenital entities (lacunar skull and dysplasia) display a diffuse pattern of skull involvement. Several benign and malignant primary bone tumors involve the calvaria and manifest as lytic, sclerotic, mixed lytic and sclerotic, or thinning lesions, whereas multifocal disease is mainly due to hematologic or secondary malignancies. Metabolic disorders such as rickets, hyperparathyroidism, renal osteodystrophy, acromegaly, and Paget disease involve the calvaria in a more diffuse pattern. Online supplemental material is available for this article. ^©RSNA, 2021.

Hyperostosing sphenoid wing meningiomas

Some sphenoid wing meningiomas are associated with a significant hyperostotic reaction of the adjacent sphenoid ridge that may even exceed the size of the intradural mass. The decision-making process and surgical planning based on neuroanatomic knowledge are the mainstays of management of this group of lesions. Given their natural history and biologic behavior, many hyperostosing meningiomas at this location require long-term management analogous to a chronic disease. This is particularly true when making initial decisions regarding treatment and planning surgical intervention, when it is important to take into consideration the possibility of further future interventions during the patient's life span.

Primary intraosseous osteolytic meningioma without an evidence of soft tissue invasion

Primary intraosseous osteolytic meningiomas are not common, and total surgical removal is the best treatment option if the location allows that; however, long-term follow-up is recommended since it may recur.

68Ga-DOTATOC-PET/CT-guided resection of a primary intraosseous meningioma: technical note

Primary intraosseous meningiomas (PIMs) are rare tumors that present with a variable radiological appearance and a clinical behavior that is considerably different from that of intracranial meningiomas. Treatment of PIMs consists of complete resection, which may be difficult to achieve due to the lack of clear tumor margins on conventional imaging studies. PET/CT using 68Ga-DOTA-conjugated peptides has been used for the diagnosis and treatment planning of different types of meningiomas due to these tracers' affinity to somatostatin receptors, which are found in most meningiomas. However, this imaging modality's use as an intraoperative adjunct has not been reported for PIMs. In this technical note, the authors describe a [68Ga-DOTA0-Tyr3]octreotide (68Ga-DOTATOC)-PET/CT-guided resection of a PIM. In this case, the area of increased uptake in the 68Ga-DOTATOC-PET/CT study extended well beyond the tumor margins identified on MRI. The patient's pathology report confirmed the presence of tumor cells within peripheral bone, which macroscopically appeared normal. The authors propose 68Ga-DOTATOC-PET/CT as a valuable adjunct in the surgical management of PIMs and offer a reasonable justification for its use based on current evidence. Its use for intraoperative image guidance may aid neurosurgeons in achieving a complete resection, thus minimizing the risk of recurrence of this complex pathological entity.

Benign purely intraosseous meningioma of the skull: Diagnosis and surgical outcomes

Primary intraosseous meningioma (PIM) is a rare subtype of extradural meningiomas that originates within bone. We aimed to characterize the clinical, radiographic, and pathologic features of PIM and the resulting outcomes following resection. Herein we examined a retrospective case series of all patients with a pathologically confirmed WHO grade I PIM that were managed at one of three tertiary care centers. Patients with tumors that demonstrated extraosseous extension or involvement of the dura mater were excluded. The main outcomes included surgical safety and duration of local tumor control. Nine patients were identified with benign PIMs, presenting with headaches or painless enlarging subcutaneous masses if involving the calvarium or with neurologic deficits if involving the skull base, or otherwise incidentally identified. Surgery was pursued for symptomatic relief and/or tissue diagnosis. Lesions were evaluated by radiographic imaging - including sensitive detection by plain X-ray films - and definitive diagnosis ascertained by histopathological examination. Maximal resection of both calvarial and skull base lesions was safely tolerated. PIM represents a rare benign skull lesion, whose identification depends on the integration of radiographic findings with intraoperative findings and histopathological confirmation; it should be considered in the differential for slow-growing expansile intraosseous lesions of the skull.

Primary intraosseous meningioma of the calvarium: A systematic review

BACKGROUND

Primary intraosseous meningiomas (PIM) of calvarial origin are a small subset of meningiomas that arise from and occur within the calvarial bone. Its definition is often confused with other forms of non-dural based intracranial meningiomas, which has made previously published retrospective reviews heterogenous, non-specific and sometimes inaccurate. We present a systematic review of calvarial PIM.

METHODS

Using a systematic search protocol that included databases such as PubMed, Web of Science and Embase, we extracted all human studies on PIM published from inception to December 2017. This systematic review includes case reports and retrospective reviews that specifically described PIM.

RESULTS

On review of 166 articles identified with the systematic search protocol, 69 articles were analyzed. These comprised of 64 case reports, 1 case series and 4 retrospective reviews. 111 patients with PIM of calvarial origin were analyzed, 58 % of which were females and 42 % males. The mean patient age was 51 years and the frontal bone was the most common tumor location, occurring in 26.1 % of the cases. Surgical resection was the predominant modality of treatment in 97.2 % of the cases, and gross total resection was achieved in 84 % of cases that reported extent of resection. There were no recurrences for grade I meningiomas. However, all grade III meningiomas recurred and 33.3 % of grade II meningiomas showed recurrence with a mean postoperative follow-up interval of 20 months. Statistical analysis using Fisher's exact test showed the recurrence rate to be strongly associated with WHO tumor grade (p-value <0.001).

CONCLUSION

There is statistically significant increased recurrence rate for calvarial PIM of higher grades, and we recommend close follow-up in those cases. Surgical resection remains the overwhelming treatment of choice for calvarial PIM, and it has a high gross total resection rate and low risk of complications and mortality.

Investigating Effective Factors on Estimated Hemorrhage Intraoperative in Brain Meningioma Surgery

Introduction

The primary and definitive diagnosis of meningioma is based on histological assessment; however, employing imaging methods, like Magnetic Resonance Imaging (MRI) is very helpful to describe lesion's characteristics. Accordingly, we decided to study the effect of imaging factors, like MRI data on the volume of hemorrhage (estimated blood loss) during meningioma surgery.

Methods

This was a cross-sectional, retrospective, and analytical study. The eligible patients were those with meningioma who were candidates for surgery. A total of 40 patients with meningioma were selected and assessed. The preoperative imaging findings were recorded, then estimated blood loss during the surgery was determined.

Results

A reverse association was revealed between the degree of proximity to the nearest sinus and the rate of bleeding. Furthermore, the size of the mass was positively associated with the rate of bleeding; however, there was no significant correlation between the volume of bleeding and other parameters, including the degree of edema, the volume of mass, the site of the tumor in the brain, and the histological subtype of the tumor. The mean time of operation was strongly correlated with blood loss. The rate of bleeding was more expected in hypertensive versus normotensive patients.

Conclusion

Bleeding in various volumes could be a frequent finding in intracranial meningioma surgery. Overall, tumor size, the duration of surgery, a history of hypertension, and distance to the nearest sinuses were the main determinants for the severity of hemorrhage in patients undergoing meningioma surgery.

Primary intraosseous meningioma: clinical, histological, and differential diagnostic aspects

OBJECTIVE

Primary intraosseous meningioma (PIM) is a rare manifestation of meningioma, a benign, neoplastic lesion of the meninges. Its characteristic appearance is hyperostosis, while no or only minimal dural changes can be observed. This study aims to characterize this rare entity from both a clinical and histopathological point of view in order to improve clinical management.

METHODS

In the years 2009-2017, 26 cases of PIM were diagnosed using MRI and CT scans. In 16 cases the indication for resection was given, and specimens were further examined using a multilevel approach, including histological and immunohistochemical analyses. Additionally, the local database was searched for all cases of meningiomas, as well as osteosclerotic differential diagnoses-i.e., fibrous dysplasia, Paget's disease of bone, and other benign osteosclerotic lesions.

RESULTS

In this study, PIM represented 2.4% of all meningiomas with a predominant occurrence in females (85%). Regarding the initial manifestation, PIMs show a slightly earlier onset than meningiomas. While most PIMs are located in the sphenoid bone, associated calcifications were visible in 58% of the cases on CT scans. Most of the cases were classified as WHO grade I (93%) and meningotheliomatous meningiomas (91%). Tumor growth was associated with an increased bone resorption followed by massive osteoid deposition and consecutive sclerosis. The frequently observed frayed appearance results from multiple bony canals, which contain blood vessels for the blood supply of the highly vascularized tumor tissue.

CONCLUSIONS

PIM is a rare but important differential diagnosis for osteosclerotic lesions of the skull, especially in women. Tumor-induced, cellular-mediated bone resorption and formation may play a central role in the underlying pathogenesis.

Computed tomographic imaging of meningiomas

Although magnetic resonance imaging (MRI) has surpassed computerized tomography (CT) as the imaging modality of choice, there are certain instances when CT should be a preoperative requisite for meningioma surgical resection. Given its superior bone definition and the propensity for meningiomas to invade bone (as evidenced by hyperostosis on imaging), CT can be extremely helpful to the surgeon when planning and evaluating postoperatively the extent of bone removal during tumor resection. Advances in CT imaging also allow for visualization of the adjacent arterial and venous vasculature to determine feasibility of resection and likelihood of adjuvant treatments such as radiosurgery to a tumor residuum. For skull base tumors high-resolution CT imaging as part of the standard neuronavigation sequences can help evaluate bony anatomy and planning of surgical approaches, in particular for cranial base tumors. Finally, 3D-CT imaging is important in the design of cranial prostheses, which may be required to repair defects as a result of resection.

Type III Intraosseous Meningioma Invading Superior Sagittal Sinus and Skull Periosteum

Type III intraosseous meningioma is a very rare type of meningioma with extracranial extension. Herein, the author reported a case of type IIIC intraosseous meningioma with invasion of the superior sagittal sinus and skull periosteum. A 67-year-old woman was admitted to our hospital due to a mass on the left frontoparietal region for 4 years. Magnetic resonance imaging showed a skull tumor with invasion of the superior sagittal sinus. After partial resection of the tumor, pathological and immunohistochemical staining revealed that the epithelial meningioma derived from skull involved the skull periosteum. There was no enlargement of residual parasagittal tumor after 1 year of follow-up. The intraosseous meningioma in the present case was a rare benign tumor with good prognosis after surgery.

Pediatric Orbital Roof Intradiploic Meningioma Operated by Eyebrow Incision

INTRODUCTION

Primary intradiploic meningiomas account for <1% of all osseous calvarial lesions and are categorized as bone tumors. They are frequently observed in the frontotemporal region of the calvarium, anterior cranial fossa, and orbit. We present a case of intradiploic meningioma of the orbital roof, which is rarely observed in the pediatric age-group; it was surgically treated with a unique minimally invasive approach.

CASE PRESENTATION

A 16-year-old male with chief complaints of headache on the right side for approximately 1 year was presented to our clinic. Cranial MRI revealed an intradiploic mass with homogeneous, hypointense contrast patterns on the T1W and T2W images of the right orbital roof. A skin incision was made through the right eyebrow, and the frontal sinus anterior wall was opened by craniotomy. Gross total resection was achieved by reaching the tumor present in the orbital roof. The mass was characterized as psammomatous meningioma by a pathological examination.

DISCUSSION/CONCLUSION

In cranial oncologic surgery, lesion localization and possible pathological diagnosis are essential for the determination of the correct surgical technique. In particular, in pediatric cases, selecting a method that will reduce the need for transfusion, shorten the surgical time, minimize the chances of facial deformity, and facilitate postoperative care will ensure compliance with the correct and appropriate treatment process.

Large solitary lytic skull vault lesions in adults: radiological review with pathological correlation

The diagnosis of a large solitary lytic skull vault lesion in adults is a challenge due to variable aggressiveness and overlapping features. The purpose of this article is to demonstrate the use of an imaging approach to narrow the differential diagnosis when a large solitary lytic skull vault lesion is encountered. The initial imaging assessment using computed tomography (CT) is invaluable in determining lesion aggressiveness based on bony margins and skull tables involvement. Further assessment with magnetic resonance (MR) imaging including diffusion weighted imaging (DWI) aids in soft tissue characterization. We present cases of large solitary lytic skull vault lesions in adults, emphasizing on salient and atypical imaging features, with pathological correlation for better understanding of the disease processes that underlie the imaging features.

Challenging the osseous component of sphenoorbital meningiomas

BACKGROUND

Intraosseous growth is a unique feature of sphenoorbital meningiomas (SOM). Its close relation to neurovascular structures limits complete surgical resection and possibly contributes to the high recurrence rate.

OBJECTIVE

To evaluate the growth behavior of intraosseous remnants and develop a protocol for precise intraoperative visualization of intraosseous SOM.

METHODS

We included 31 patients operated for SOM from 2004 to 2017. The growth velocity of the intraosseous tumor component was volumetrically calculated in 20 cases. To improve accuracy of image guidance, we implemented a specialized bone surface-based registration algorithm. For intraoperative bone visualization, we included CT in multimodality continuous image guidance in 23 patients. The extent of resection (EOR) was compared with a standard MR-only navigation group (n = 8).

RESULTS

In 11/20 cases (55%), a progressive regrowth of the intraosseous SOM remnant was noted during a mean follow-up of 52 months (range 20-132 months). We observed a mean increase of 6.2 cm3 (range 0.2-23.7 cm3) per patient and side during the follow-up period. Bone surface-based registration was significantly more accurate than skin surface-based registration (mean 0.7 ± 0.4 mm and 1.9 ± 0.7 mm, p < 0.001). The EOR of the intraosseous component was significantly higher using CT + MRI navigation compared with controls (96% vs. 81%, p = 0.044).

CONCLUSION

Quantitative assessment of the biological behavior of intraosseous remnants revealed a continuous slow growth rate independent of the soft tumor component of more than half of SOM. According to our data, application of a multimodal image guidance provided high accuracy and significantly increased the resection rate of the intraosseous component of SOM.

Removal of giant intraosseous meningioma followed by cranioplasty using a custom-made bioceramic implant: case report

Intraosseous meningioma of the chordoid type is a rare clinical entity. Radical surgical removal and subsequent cranioplasty is the treatment of choice. Here, the authors report a severe case involving more than 70% of the calvarial surface area, which was removed and repaired using a prefabricated custom-made, titanium-reinforced, bioceramic implant and bone-cutting guides. Tumor removal and good esthetic outcome were achieved, along with a 17.1% increase of intracranial volume. Bioceramic implants have shown promising initial results and may represent an important new tool in the surgeon's armamentarium.

Primary intraosseous osteolytic meningioma: a case report and review of the literature

BACKGROUND

Primary intraosseous meningioma is a subset of extradural meningioma that arises in the bone, and only a few cases have been reported to date.

CASE PRESENTATION

An 80-year-old man presented with decreased hearing on the right side accompanied by a disturbance of balance 10 months prior to admission. Magnetic resonance imaging revealed an 8 × 7 cm osteolytic mass in the right posterior fossa related to the petrous bone, with extension to the cervical region. During surgery, the tumor was found to be located extradurally, with no invasion of the dura. The tumor was removed entirely, apart from a small portion around the jugular foramen to avoid lower cranial nerve injury.

CONCLUSION

The final diagnosis was primary intraosseous osteolytic meningioma with atypical pathology. Here, we report a rare case of an osteolytic skull lesion in the skull base not invading the dura and with extensive bone destruction.

Bony Hyperostosis Recurrence after Complete Resection of Sphenoorbital Meningioma

Bony hyperostosis is commonly associated with meningioma growth and is considered one of the characteristic signs on imaging; however, recurrence of meningiomas in the sphenoorbital area, including associated hyperostosis, is typically precluded by gross total resection of the lesion. This 63-year-old man presented with progressive double vision and proptosis in the right eye. He underwent frontotemporal craniotomy and partial removal after magnetic resonance imaging demonstrated a right sphenoorbital meningioma extending to the orbit and middle fossa. He had transient improvement of his symptoms postoperatively but experienced a progressive recurrence of symptoms and new onset of right facial hypoesthesia in the distribution of V1 and V2. We performed a right frontotemporal craniotomy with removal of the nodular part, as well as extensive drilling. Although the postoperative computed tomography scan revealed a gross total resection, the five-year follow-up scan demonstrated a recurrent hyperostosis in the region of the lesser and greater sphenoid wings, the middle cranial fossa floor with inferior extension toward the infratemporal fossa, and the sphenoid sinus wall. After another redo surgery, the patient continues to be monitored with yearly imaging. The extent of surgical resection is one of the most important predictors of meningioma recurrence postoperatively, and cases of recurrence after gross total resection are rare.

Frontal intradiploic meningioma with progressive intracranial invasion: A rare case report

RATIONALE

Intradiploic meningiomas are a subset of extradural meningiomas that arise in the skull. They are mostly localized in the frontoparietal and orbital regions, and they are often mistaken for primary bone tumors.

PATIENT CONCERNS

The patient was a 48-year-old man with headache and a 12-year history of frontal cranium occupation, which was first discovered in 2005 and enlarged in 2009. The patient had a history of fracture in his frontal cranium 12 years ago. The computed tomography and magnetic resonance imaging revealed an occupation and intracranial invasion in frontal cranium. And the angiography showed an occlusion at the anterior part of sagittal sinus.

INTERVENTIONS

Bilateral frontal craniotomy, intracranial tumor resection, and cranioplasty were performed.

DIAGNOSIS

Histologic examination confirmed an intradiploic ectopic meningioma (World Health Organization Grade I).

OUTCOMES

He was discharged with no neurological deficits 3 days after surgery. At the 6-month clinical follow-up, there was no tumor recurrence or other complaints.

LESSONS

In this study, we present the case of a frontal intradiploic meningioma with progressive intracranial invasion and review the radiographic and clinical findings of patients with primary intraosseous meningioma.

A primary intraosseous cystic meningioma: Case report

INTRODUCTION

This is a very rare case of intraosseous cystic meningioma. There have been no reports of similar cases in the last 30 years.

PRESENTATION OF CASE

A 62-year-old man, suffering from a swelling of the lateral wall of the left orbit was admitted to our hospital. MRI and CT scan showed a large intradiploic lesion involving the lateral wall of the orbit and the greater wing of the sphenoid. The lesion was cystic with a mural nodule. We operated the patient and removed completely the mural nodule and the fibrous wall of cyst. Histological examination showed that the mural nodule was a benign meningothelial meningioma.

DISCUSSION

Primary intraosseous meningiomas represent a subtype of primary extradural meningiomas; they comprise about 2% of all meningiomas and are therefore rare entities. Cystic meningiomas are rare, their incidence compared to all other types of meningiomas is of 2-4%. The presence of a meningioma with both characteristics: cystic and intraosseous, like in our case, is an exceptional occurrence.

CONCLUSION

The surgical management of tumor was easy; its rarity means that the case is interesting.

Hyperostotic sphenoid wing meningioma en plaque: proptosis management

Background: En plaque sphenoid wing meningioma is morphological unique in comparison with other intracranial meningiomas, characterized by a carpet-like usually small soft tissue component which invade the dura and extensively involve the bone specially the sphenoid wing and orbit causing significant hyperostosis. Patients & Methods: A retrospective analysis of the clinical data, neuro-radiological features, and operative techniques of eighteen patients underwent transcranio-orbital approach sphenoid wing meningioma presented with proptosis during the period from September 2011 to April 2014 in the neurosurgery department, Mansoura University. Patients age ranged from 38 years to 54 years and there was sex males and twelve females. Chief complaints were progressive proptosis and visual acuity deficits. All patients were operated up on using a fronto-temporal approach with orbital decompression. The extent of tumor resection and postoperative complications were investigated. Results: Total removal was achieved in fourteen cases (77.8%) over a mean follow-up period of 36 months. Pathological examination showed that twelve patients (66.67%) were meningothelial meningiomas. After surgery, proptosis improved in all patients, visual acuity improved in fifteen patients (83.3%). Cerebrospinal fluid leakage was found in one patient. There were no operation-related deaths or other significant complications. Four patients had residual tumor (22.2%); two of them underwent surgical re-attack of the tumor and the other two cases were sent for gamma knife radio-surgery. Conclusions: Sphenoid wing meningioma en plaque, mainly meningothelial meningiomas, are characterized by the associated bony hyperostosis that gives them a distinct radiological appearance. The bony hyperostosis is of neoplastic nature and is responsible for many of the clinical manifestation of such tumors and hence should be totally drilled to achieve cure and avoid recurrence. Extensive tumor removal is crucial for correction of proptosis and adequate visual decompression to achieve satisfactory cosmetic and functional outcome.

Primary intraosseous meningioma: an osteosclerotic bone tumour mimicking malignancy

BACKGROUND

Sclerotic tumours of the calvarial bones are rare and may be due to primary and secondary bone tumours as well as extradural tumours of meningeal origin.

CASE PRESENTATION

We report a case of primary intraosseous meningioma (PIM) which arose in the frontal bone of a 63 year old woman who complained of progressive pain and thickening of the right skull. Radiology showed a large osteosclerotic lesion in the right frontal bone. Histology showed an intraosseous lesion containing dense fibrous tissue in which there were scattered cells that expressed epithelial membrane antigen and progesterone receptor. The tumour was partially resected and 3 years after operation has not recurred.

CONCLUSIONS

PIM is a rare tumour which needs to be distinguished from primary/secondary osteosclerotic calvarial bone tumours.

Osteolytic clear cell meningioma of the petrous bone occurring 36 years after posterior cranial fossa irradiation: Case report

OBJECTIVE AND IMPORTANCE

While bone invasion and hyperostosis are frequent phenomena in meningiomas, primary intraosseous meningiomas are rare and their occurrence in the skull base is an extraordinary exception. Moreover, radiation-induced meningiomas represent a unique clinical dilemma given the fact that patients with these tumors had often received a prior full course of radiotherapy.

CLINICAL PRESENTATION

A 42-year-old man presented with a 3-month history of progressively worsening facial asymmetry. His medical history was consistent for a posterior cranial fossa irradiation at the age of 6 years for a non-confirmed brain stem tumor. On admission his Karnofsky performance status was graded as 50% and his neurological examination showed a complete right facial nerve paralysis and hearing impairment. Computed tomography and magnetic resonance imaging demonstrated an osteolytic tumor invading the whole right petrous bone without intracranial involvement.

INTERVENTION

As the tumor reached the external auditory canal, a tissue sample was obtained locally. Pathological examination of the lesion identified a grade II clear cell meningioma and the patient was consequently addressed for an intensity modulated radiation therapy. His condition remained unchanged till the most recent follow-up examination, 8 months later.

CONCLUSIONS

To the best of our knowledge, a radiation induced osteolytic clear cell meningioma of the petrous bone has not been previously reported. As little literature exists regarding the use of adjuvant therapies for these tumors, intensity modulated radiation therapy remains an attractive treatment option in case of pervious irradiation and general status alteration.

Imaging of focal calvarial lesions

Focal calvarial lesions may present as a visible, palpable, or symptomatic lump; however, with increasing use of cross-sectional imaging they are often encountered as an incidental finding. Knowledge of the possible disease entities along with a structured approach to imaging is required to suggest an appropriate diagnosis and assist in management planning. Abnormalities range from common neoplastic lesions to rarer congenital conditions, benign pathologies, and calvarial defects that can mimic lesions. The aim of this article is to demonstrate the salient imaging features that may help to limit the differential diagnosis of a focal calvarial lesion.

Primary Intraosseous Osteolytic Meningioma of the Skull Mimicking Scalp Mass: A Case Report and Review of Literature

Primary extradural meningioma is about 1-2% of all meningiomas. Primary intraosseous meningioma is a rare form of intra-bone tumors that account for approximately 67% of extradural meningiomas. We report a primary intraosseous meningioma of a 69-year-old man who had headaches and a mass on right parietal scalp for the past few months. Remarkably, the brain tissue within the osteolytic cavity of the skull was normal in computed tomography and magnetic resonance images. Resection, duraplasty, and cranioplasty were performed. The patient's symptoms disappeared after surgery, and the histological diagnosis was an osseous meningothelial meningioma (World Health Organization grade I).

Double concentric craniotomy: Safe and effective technique to achieve an en bloc resection of tumor involving both skull and duraa

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Many tumors can involve the skull. Radical excision is the golden standard of treatment.

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Elevate a bone flap when the tumor involves both the skull and the dura present a technical challenges.

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Double concentric craniotomy is a safe and effective technique to remove tumor involving both skull and dura structures under direct vision.

Introduction

Many tumors can involve the skull. Meningiomas are one of the most common intracranial neoplasms and invasion of the bone was described in 49% of cases. Other neoplastic lesions that can arise in bone, or involve it, are metastases, hemangiomas, aggressive cutis carcinomas and sarcomas. Radical excision is the golden standard of treatment but elevating a bone flap when the tumor involves both the skull and the dura could represent a technical challenge.

Presentation of case

We report the technical details of our approach to remove a meningioma involving both skull and dura in a man aged 45. Patient underwent gross total excision and cranioplasty with PEEK custom made prothesis (Synthes™).

Discussion

We describe a double concentric craniotomy (DCC) technique where the tumor involving the bone is before left in situ, exposing normal dura, to perform afterwards en-bloc excision with minimal traction of brain surface.

Conclusion

DCC is a safe and effective technique to remove tumor involving both skull and dural structures under direct vision.

Primary intraosseous meningioma in the calvaria: morphological feature changes on magnetic resonance images over several years

Primary intraosseous meningiomas (PIMs) are rare, and their pathogenesis remains unclear. We report the case of a sizable PIM in the calvaria that progressively enlarged over several years and presented temporal changes in the morphological features on magnetic resonance images. Along with discussing the case, we further emphasize the potential pitfalls of diagnosing a PIM in the calvaria.

Microcystic meningioma of the calvarium: a series of 9 cases and review of the literature

Meningiomas are one of the most common tumors that arise within the central nervous system; they represent up to 30% of all primary intracranial tumors. Extradural meningiomas are rare (<2% of all meningiomas), and most arise within the calvarium. Intraosseous calvarial meningiomas are usually easy to diagnose histologically if they are of the meningothelial type; however, they may cause diagnostic challenges when they manifest as unusual morphologic variants, such as the microcystic type. To address this issue we present a series of 9 cases of calvarial microcystic meningiomas arising in 7 female and 2 male patients; all patients were adults. The tumors had heterogenous findings on imaging studies and ranged in size from 1.1 to 4.3 cm in greatest dimension. The neoplasms were composed predominantly of stellate and spindle cells with long, thin interconnecting cytoplasmic processes arranged in a complex network. The resulting cellular architecture was "sieve-like" in appearance because of the formation of numerous small "cyst-like" spaces interposed between the cytoplasmic processes of the tumor cells. All of the neoplasms expressed the characteristic immunophenotype of meningiomas (EMA, PR positive). Most tumors were resected, and none of these have recurred during a follow-up period of 1 to 83 months (average 17 mo). The morphology of the tumors and their anatomic location generated problems in diagnosis, especially in 6 patients with a history of malignancy and for whom metastatic disease was suspected clinically. Intraosseous microcystic meningioma is uncommon, and this series, the largest reported to date, describes their clinicopathologic findings, biological behavior, and features that facilitate their accurate diagnosis.

Surgical management of a transosseous meningioma with invasion of torcula, superior sagittal sinus, transverse sinus, calvaria, and scalp

Background:

Meningiomas involving both intradural and extradural structures are rare tumors. We report the complete resection of a massive complex transosseous meningioma that had invaded the torcula, superior sagittal sinus, occipital bone, and scalp.

Case Description:

A 48-year-old male presented after 3 days of worsening headaches and blurry vision. Preoperative imaging demonstrated an 11 × 5-cm extra-axial mass that avidly enhanced with gadolinium in the region of the torcula. Angiography demonstrated occlusion of the involved portions of the superior sagittal sinus, torcula, and proximal left transverse sinus. Cortical drainage occurred via the veins of Labbι and deep drainage via an occipital sinus. Using image-guided stereotaxy, a wide-excision scalp resection and craniectomy with sinus exploration was planned for complete tumor removal. Parasitized cortical veins were preserved. Occluded portions of the superior sagittal sinus and left transverse sinus were resected along with the invaded parts of the falx and tentorium. The walls of the straight sinus, torcula, and right transverse sinus were repaired primarily to facilitate deep drainage. A latissimus dorsi free flap was used to reconstruct the scalp defect. Routine follow-up magnetic resonance imaging (MRI) at 18 months demonstrated no evidence of recurrence or regrowth.

Conclusions:

This case illustrates the importance of identifying aberrant venous drainage pathways when considering ligation and resection of major sinuses and discusses the management of calvarial and scalp invasion.

Calvarial ectopic meningothelial meningioma

BACKGROUND

Meningiomas are the most common benign neoplasm of the brain whereas ectopic presentation, although reported, is rare. Among these ectopic tumors, there are a group of purely intraosseous meningiomas, which usually are diagnosed differentially from common primary osseous tumor such as fibrous dysplasia and osteoid osteoma.

CASE DESCRIPTION

We report a 62-year-old female with a history of headaches and 6 months of progressive right parietal bulging, with no neurological signs. Parietal craniotomy was performed with immediate titanium cranioplasty of the parietal convexity. Histopathology exams revealed an ectopic intradiploic meningioma without invasion of cortical layers, with positive staining for progesterone receptors and epithelial membrane antigen.

CONCLUSIONS

Ectopic intraosseous meningiomas remain a rare neoplasm with only a few cases reported. The main theories to justify the unusual topography appear to be embryological remains of neuroectodermal tissue or cellular dedifferentiation. Surgical treatment seems the best curative option.

[Primary osteolytic intraosseous meningioma of the occipital bone]

Primary intraosseous meningiomas are considered extradural meningiomas when no dural attachment is present. Most of them arise from the cranial bones and can present either as an osteoblastic or an osteolytic lesion. Osteolytic intraosseous meningiomas are the rarest and very few cases have been reported. Given that many of these may develop signs of malignancy, early histological confirmation is important in order to ensure appropriate treatment. The recommended therapy is surgery, with complete resection whenever possible. We present the case of a large primary intraosseous osteolytic meningioma within the occipital bone, which was completely excised five years ago, currently presenting no signs of recurrence.

Primary osteolytic intraosseous atypical meningioma with soft tissue and dural invasion: report of a case and review of literatures

Primary intraosseous meningioma is a rare tumor, and atypical pathologic components both osteolytic lesion and dura and soft tissue invasion is extremely rare. A 65-year-old woman presented with a 5-month history of a soft mass on the right frontal area. MR imaging revealed a 4 cm sized, multilobulated, strongly-enhancing lesion on the right frontal bone, and CT showed a destructive skull lesion. The mass was adhered tightly to the scalp and dura mater, and it extended to some part of the outer and inner dural layers without brain invasion. The extradural mass and soft tissue mass were totally removed simultaneously and we reconstructed the calvarial defect with artificial bone material. The pathological study revealed an atypical meningioma as World Health Organization grade II. Six months after the operation, brain MR imaging showed that not found recurrence in both cranial and spinal lesion. Here, we report a case of primary osteolytic intraosseous atypical meningioma with soft tissue and dural invasion.