Primary intraosseous meningiomas

Case of infiltrative optic neuropathy with hypertrophic pachymeningitis as a manifestation of en plaque meningioma

We describe a case of infiltrative optic neuropathy with hypertrophic pachymeningitis noted on MRI of the brain, presenting a diagnostic dilemma with a wide variety of differential diagnoses to consider. Our patient is a middle-aged woman with a 20-year history of migranous-sounding headaches who was incidentally found to have worsening vision in her left eye during a routine driving test visual acuity check. Neurological examination revealed a left grade III relative afferent pupillary defect and a central scotoma with red desaturation. Subsequent MRI of her brain and anterior visual pathway revealed features suggestive of an infiltrative left optic neuropathy with hypertrophic pachymeningitis. An extended workup including diagnostic lumbar puncture and blood tests for possible autoimmune, infective and neoplastic causes proved unyielding. Eventually, an endoscopic transsphenoidal biopsy helped to clinch the diagnosis of a (meningothelial subtype) WHO grade 1 meningioma as the cause of her clinical and radiological presentation.

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.

Intraosseous Meningioma of Spheno-Orbital Localization: A Case Report

Intracranial meningiomas are benign extra-axial brain tumors. Their etiology is undetermined and several hypotheses have been proposed to explain their genesis. The clinical symptomatology of intracranial meningiomas is atypical and varies according to the location of the lesion, its size, and its relationship with neighboring organs. Imaging is essential for establishing a positive diagnosis, but the way to a diagnosis of certainty remains histological. In this article, we describe the CT and magnetic resonance imaging aspects of an intraosseous meningioma discovered in a patient in her forties that presented with right proptosis, and whose brain MRI revealed a cranial lesion with adjacent meningeal involvement; the CT scan subsequently performed allowed a better analysis of the bone lesion, the appearance of which suggested an intraosseous meningioma. This diagnosis was confirmed by a histological exam. The purpose of this article is to illustrate the CT and MRI aspects of this entity by reporting a case of intraosseous meningioma of spheno-orbital location.

Cranial meningioma with bone involvement: surgical strategies and clinical considerations

BACKGROUND

Intracranial meningioma with bone involvement and primary intraosseous meningioma is uncommon. There is currently no consensus for optimal management. This study aimed to describe the management strategy and outcomes for a 10-year illustrative cohort, and propose an algorithm to aid clinicians in selecting cranioplasty material in such patients.

METHODS

A single-centre, retrospective cohort study (January 2010-August 2021). All adult patients requiring cranial reconstruction due to meningioma with bone involvement or primary intraosseous meningioma were included. Baseline patient and meningioma characteristics, surgical strategy, and surgical morbidity were examined. Descriptive statistics were performed using SPSS v24.0. Data visualisation was performed using R v4.1.0.

RESULTS

Thirty-three patients were identified (mean age 56 years; SD 15) There were 19 females. Twenty-nine patients had secondary bone involvement (88%). Four had primary intraosseous meningioma (12%). Nineteen had gross total resection (GTR; 58%). Thirty had primary 'on-table' cranioplasty (91%). Cranioplasty materials included pre-fabricated polymethyl methacrylate (pPMMA) (n = 12; 36%), titanium mesh (n = 10; 30%), hand-moulded polymethyl methacrylate cement (hPMMA) (n = 4; 12%), pre-fabricated titanium plate (n = 4; 12%), hydroxyapatite (n = 2; 6%), and a single case combining titanium mesh with hPMMA cement (n = 1; 3%). Five patients required reoperation for a postoperative complication (15%).

CONCLUSION

Meningioma with bone involvement and primary intraosseous meningioma often requires cranial reconstruction, but this may not be evident prior to surgical resection. Our experience demonstrates that a wide variety of materials have been used successfully, but that pre-fabricated materials may be associated with fewer postoperative complications. Further research within this population is warranted to identify the most appropriate operative strategy.

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.

Giant Intraosseous Meningioma Associated with Calvarial Hyperostosis and Subcutaneous Invasion: Case Reports and Literature Review

Most meningiomas grow intracranially, and primary intraosseous meningioma is rarely reported. We present two rare surgical cases of giant intraosseous meningothelial meningioma. The first patient was a 35-year-old male with parietal skull deformity without neurological symptoms. Total resection was successful. The origin was the parasagittal intraosseous layer, and the superior sagittal sinus was partially opened. The second patient was a 20-year-old female with a slightly upward protrusion of the frontal skull without pain or neurological deficits. The lesion was totally resected, and the origin was the parasagittal intraosseous layer invading into the dura matter and subcutaneous layer. The clinical management of these cases presented a surgical challenge because of detachment and repair from venous sinuses. The current report provides surgical tips for such rare diseases and is a good reference for the future treatment of similar diseases.

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.

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.

The Alberta standardized orbital technique in the management of spheno-orbital meningiomas

PURPOSE

To describe a standardized orbital resection technique and outcomes for spheno-orbital meningiomas with soft-tissue invasion of the orbit.

METHODS

A retrospective case review of patients with spheno-orbital meningioma that underwent resection utilizing the Alberta Standardized Orbital Technique (ASOT) between 2008 and 2017 was performed.

RESULTS

Twenty patients met the inclusion criteria. Fifteen females and five males, with an average age of 53.4 years (SD ± 13.1 years). Mean follow-up was 57.3 months (SD ± 29.5 months). Eight cases (40%) had attempted resection prior to referral. Based on pre-operative plan, patients were divided into two groups based on goal of resection. Of those with planned complete resection (Group I), 11/13 patients (84.6%) underwent complete excision, with no cases of orbital recurrence. Incomplete resection in two cases occurred because of unexpected involvement of critical intra-cranial structures. Thus, in total 9/20 patients (Group II and 2 from Group I) underwent subtotal resection. Of these incomplete resections, five cases of orbital recurrence were observed; four patients required adjuvant external beam radiotherapy (EBRT) and one patient underwent further debulking surgery. Orbital control was achieved in three of these recurrent cases. Complications reported were persistent postoperative diplopia (three cases/15%) and wound infection (one case/5%). Overall, stable orbital disease was obtained in 18 patients (90%).

CONCLUSION

The ASOT demonstrated to be effective, achieving the pre-operative plan of complete resection in 11/13 cases (84.6%) with no recurrence in those with clear orbital margins.

Hyperostosing sphenoid wing meningiomas: surgical outcomes and strategy for bone resection and multidisciplinary orbital reconstruction

OBJECTIVE

Hyperostosing sphenoid wing meningiomas cause bony hyperostosis that may extend into the orbit, resulting in proptosis, restriction of extraocular movements, and/or compressive optic neuropathy. The extent of bony removal necessary and the optimal reconstruction strategy to prevent enophthalmos is debated. Herein, the authors present their surgical outcomes and reconstruction results.

METHODS

This is a retrospective review of 54 consecutive patients undergoing resection of sphenoid wing meningiomas associated with bony hyperostosis. The majority of cases were operated on by the senior author. Extent of tumor resection, volumetric bone resection, radiographic exophthalmos index, complications, and recurrence were analyzed.

RESULTS

The median age of the cohort was 52.1 years, with women comprising 83% of patients. Proptosis was a presenting symptom in 74%, and 52% had decreased visual acuity. The WHO grade was I (85%) or II (15%). The median follow-up was 2.6 years. On volumetric analysis, a median 86% of hyperostotic bone was resected. Gross-total resection of the intracranial tumor was achieved in 43% and the orbital tumor in 27%, and of all intracranial and orbital components in 20%. Orbital reconstruction was performed in 96% of patients. Postoperative vision was stable or improved in 98% of patients and diplopia improved in 89%. Postoperative complications occurred in 44% of patients, and 26% of patients underwent additional surgery for complication management. The most frequent complications were medical complications and extraocular movement deficits. The median preoperative exophthalmos index was 1.26, which improved to 1.12 immediately postoperatively and to 1.09 at the 6-month follow-up (p < 0.001). Postoperatively, 18 patients (33%) underwent adjuvant radiotherapy after subtotal resection. Tumors recurred/progressed in 12 patients (22%).

CONCLUSIONS

Resection of hyperostosing sphenoid wing meningiomas, particularly achieving gross-total resection of hyperostotic bone with a good aesthetic result, is challenging and associated with notable medical and ocular morbidity. Recurrence rates in this series are higher than previously reported. Nevertheless, the authors were able to attain improvement in proptosis and visual symptoms in the majority of patients by using a multidisciplinary approach.

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.

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.

Surgical Management of Extracranial Meningiomas Arising in the Head and Neck

PURPOSE

To determine outcomes in the management of extracranial meningiomas of the head and neck.

PATIENTS AND METHODS

This is a retrospective single-surgeon series performed at a tertiary-care referral center. In all, 23 patients met the inclusion criteria, consisting of 12 men and 11 women. The mean age of patients treated was 60.5 years (range, 32 to 71 years). Subsite involvement included the infratemporal fossa (n = 8), greater wing of the sphenoid and orbit (n = 7), clivus (n = 2), and parapharyngeal space (n = 6).

RESULTS

In all, recurrence occurred in 21% of patients (n = 5) who underwent gross tumor resection. Two patients underwent subtotal resection because of the tumor's location within the clivus with adjuvant CyberKnife therapy (Accuray, Sunnyvale, CA). Both patients had persistent disease with no new neurologic symptoms. Examination showed that 100% of patients (N = 23) had dural involvement. Post-ablative complications occurred in 43% of patients (n = 10).

CONCLUSIONS

We presently report the largest series of surgical treatment for extracranial meningiomas. Gross tumor resection should be the mainstay of therapy, except in anatomically restricted regions such as the petrous apex and clivus. Adjuvant therapy including CyberKnife therapy may be used in such lesions. All lesions showed dural involvement. A more unified nomenclature is required for the characterization of these lesions.

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.

Extra-axial brain tumors

Extra-axial brain tumors are the most common adult intracranial neoplasms and encompass a broad spectrum of pathologic subtypes. Meningiomas are the most common extra-axial brain tumor (approximately one-third of all intracranial neoplasms) and typically present as slowly growing dural-based masses. Benign meningiomas are very common, and may occasionally be difficult to differentiate from more aggressive subtypes (i.e., atypical or malignant varieties) or other dural-based masses with more aggressive biologic behavior (e.g., hemangiopericytoma or dural-based metastases). Many neoplasms that typically affect the brain parenchyma (intra-axial), such as gliomas, may also present with primary or secondary extra-axial involvement. This chapter provides a general and concise overview of the common types of extra-axial tumors and their typical imaging features.

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.

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.

Diffusion-weighted imaging of skull lesions

Diffusion-weighted imaging can increase the conspicuity of skull lesions and be applied toward noninvasive differentiation of malignant from benign lesions. Malignant skull lesions generally display lower diffusivity than benign lesions, although there are exceptions, and clinical parameters and conventional imaging modalities should also be considered in the evaluation of skull lesions. Nevertheless, in some instances diffusion-weighted imaging (DWI) can be used for problem solving when conventional imaging features are indeterminate, such as with skull base involvement by nasopharyngeal carcinoma versus osteomyelitis. In addition, DWI may be useful for monitoring treatment effects. The use of readout segmented technique, parallel imaging, multishot acquisition, turbo spin-echo DWI, diffusion tensor imaging, and higher field strengths can improve image quality. The feasibility of implementing DWI for characterizing skull lesions, the DWI findings of benign and malignant skull lesions, and technical considerations are discussed in this article.

18F-Fluoride PET/CT allows detection of hyperostosis and osseous involvement in meningioma: initial experience

PURPOSE

The present study was conducted to assess the diagnostic performance of (18)F-fluoride PET/CT in evaluating hyperostosis and osseous involvement in patients with meningioma.

PATIENTS AND METHODS

Thirty-four patients with meningioma (mean age, 61 years) underwent (18)F-fluoride PET/CT before surgery. In 24 patients (71%), (18)F-FDG PET/CT was also given before surgery, and the results were compared. The images were reviewed by 2 board-certified nuclear medicine specialists who were unaware of any clinical information and a consensus was reached. Uptake patterns and measurements of tracers were compared with pathological findings from resected specimens, with hyperostosis and osseous involvement as the reference standard.

RESULTS

There were 27 grade I tumors (79%) and 7 grade II tumors (21%). The primary tumor focus was identified in each patient using both (18)`F-fluoride PET/CT and (18)F-FDG PET/CT, but there were no significant correlations in the degree of uptake between the 2 tracers. The SUV(max), SUV(max) corrected for lean body mass (SUL(max)), and tumor metabolic volume (TMV) for (18)F-fluoride and (18)F-FDG were greater in grade II tumors than in grade I tumors. Hyperostosis and osseous involvement was identified in 12 tumors (38%). The SUV(max), SUL(max), and TMV of tumors visualized with (18)F-fluoride PET/CT were greater in tumors with hyperostosis and osseous involvement than in those without (P = 0.005, P = 0.003, and P = 0.006, respectively). In contrast, the SUV(max), SUL(max), and TMV of tumors visualized with (18)F-FDG PET/CT were similar regardless of hyperostosis or osseous involvement.

CONCLUSIONS

(18)F-fluoride PET/CT may improve detection of hyperostosis and osseous involvement in patients with meningioma.

Imaging pattern of calvarial lesions in adults

Calvarial lesions often present themselves as clinically silent findings on skull radiographs or as palpable masses that may cause localized pain or soreness. This review aims to explore the radiographic, computed tomography (CT), and magnetic resonance imaging (MRI) characteristics of calvarial neoplastic, inflammatory, and congenital lesions that are common in adults in order to facilitate a structured approach to their diagnosis and limit the differential diagnosis. In addition to reviewing the literature, we reviewed the records of 141 patients of the Montreal Neurological Institute and Hospital with radiologically documented calvarial lesions between 2001 and June 2009. CT is ideal for detecting bony lesions and is helpful in precisely localizing a lesion pre-surgically. MRI is best at identifying intradiploic lesions before they affect the cortical tables and is able to establish extraosseous involvement, especially when paramagnetic contrast is employed.

Primary orbital meningioma: a study of six cases at a single institution

Primary orbital meningioma is a rare tumor of the anterior visual pathway and constitutes approximately 2% of all orbital tumors and 1-2% of all meningiomas. The differentiation from secondary orbital meningioma of intracranial origin is sometimes difficult on image. As the tumor often leads to visual loss if left untreated and surgical intervention inevitably causes morbidity, the timing and modality of treatment are very important. We carried out the study involving six cases (mean age: 42.7 years, male to female ratio: 1:5) of primary orbital meningioma to further elucidate its behavior. The clinical signs and symptoms, diagnosis, treatment strategies, and follow-up information are recorded for all cases. The most frequent initial symptoms were visual complaints (100%) and proptosis (67%). In five cases, the diagnosis was based on pathologic findings and the tumors were all grade I meningiomas. In one case, however, the diagnosis was based on radiographic and clinical findings, lacking histologic confirmation. Five patients were operated on, four underwent tumor removal, and one received eyeball exenteration. One patient was treated with Novalis radiotherapy. The mean follow-up period was 8.8 years (range from 9 months to 15 years). All patients experienced loss of vision during the course without exception. No recurrent tumor was found in five cases during follow-up. In case 5, whose eyeball was exenterated, developed recurrent meningioma 7 years later. She received radiotherapy but the tumor was out of control. She expired 8 years after eyeball exenteration. The primary orbital meningioma is aggressive in behavior despite its benign histopathologic features. Loss of vision is frequently seen even after treatment. The tumor could be fatal if surgery and radiotherapy fail to control its intracranial extension.

[Sphenoorbital meningiomas: results in long-term treatment]

BACKGROUND

The purpose of this study was to present the findings on growth patterns in a large surgical series of sphenoorbital meningiomas.

PATIENTS AND METHODS

A retrospective analysis was performed on 77 patients (61 f) harboring sphenoorbital meningiomas, who underwent surgery between 1991 and 2009. The standard surgical approach consisted of pterional craniotomy and extradural resection of any infiltrated bone. The intradural and orbital tumor was resected, with complete reconstruction of the dura while the lateral bone was partially reconstructed. The follow-up period ranged from 6 to 130 months (mean: 57.9 months).

RESULTS

Total macroscopic resection was achieved in 42 patients. Fifty-eight meningiomas extended to the orbital roof and/or lateral orbital wall, 42 involved the extraconal space, and 11 the intraconal space. Sixty-three tumors involved the superior orbital fissure, 54 the optic canal, and 24 the inferior orbital fissure. Seventeen tumors infiltrated the cavernous sinus and 37 involved the anterior clinoid process. The rate of minor morbidity was 14.3% (slight deficits) and the rate of major morbidity was 4% (significant deficits). Subtotal resections were performed on 35 patients because there was intraorbital tumor (n=8); tumor in the cavernous sinus (n=12); tumor invading the superior orbital fissure (n=12); and tumor of the skull base (n=3). Nine patients underwent postoperative three-dimensional conformal radiotherapy, which resulted in stable tumor volume at follow-up in eight patients. Tumor recurrence was identified in ten patients (12.9%) postoperatively (range of follow-up: 10-47 months).

CONCLUSION

The goal of surgery is complete tumor removal without morbidity. Exact analysis of tumor growth and possible involvement of pertinent structures are mandatory in planning the procedure.

Desmoplastic fibroma of the skull

Desmoplastic fibroma is a primary bone tumour which occurs exceedingly rarely in the cranial bones. We report a histopathologically confirmed example in a 21 year old man with a painless swelling over the sagittal suture. In the light of our experience and reports of previous examples, we review the features of the condition and its management.

Primary intraosseous meningioma

✓Primary intraosseous meningiomas are a subtype of primary extradural meningiomas and constitute fewer than 2% of meningiomas overall, but they represent approximately two thirds of all extradural meningiomas. These types of meningiomas originate within the bones of the skull and thus can have a clinical presentation and radiographic differential diagnosis that is different from those for intradural meningiomas.

Primary intraosseous meningiomas are classified based on their location and histopathological characteristics. Treatment primarily involves resection with wide margins if possible. Very little literature exists regarding the use of adjuvant therapies such as radiation and chemotherapy for these tumors. In fact, the literature regarding primary intra-osseous meningiomas consists mostly of clinical case reports and case series. This literature is reviewed and summarized in this article.

Dural involvement in primary extradural meningiomas of the cranial vault

Object

The authors retrospectively analyzed a consecutive series of patients with cranial vault primary extradural meningioma (PEM), with particular regard to the tumor’s dural involvement. The pertinent literature was reviewed.

Methods

Clinical data were retrospectively obtained in a consecutive series of 16 patients treated for a PEM at two institutions between 1992 and 2004. The authors created a classification system based on dural involvement of the tumors.

Nine women and six men (mean age 55 years) presented with a painless, slowly progressive swelling. Preoperative magnetic resonance (MR) imaging revealed dural enhancement at the site of tumor in 11 patients. On surgical inspection, the tumor infiltrated the dura in all but three patients. Histological examination of tissue samples demonstrated tumor infiltration of the dura in all 14 patients in whom the dura had been resected. Three recurrent tumors were observed on follow-up examination during a mean period of 5.8 years (range 1.5–13 years) and required extirpation. In addition to one patient in whom there was histological evidence of malignancy, the other two cases involved two patients in whom no apparent dural involvement was observed during the first surgery. In a review of the literature, the authors found that histological examination showed dural involvement in 22%; the dura was not histologically evaluated in the remaining patients (78%). Postoperative follow-up data exceeding 2 years were only provided in two of the reported cases.

Conclusions

Tumor infiltration of the dura should be assumed in PEMs of the cranial vault, and resection of the dura at the site of craniotomy is recommended to prevent tumor recurrence.

Management of meningiomas en plaque of the sphenoid wing

Object

The authors present their findings on growth patterns in a large series of surgically treated meningiomas en plaque of the sphenoid wing.

Methods

A retrospective case analysis was performed in 67 patients (53 of whom were female) harboring meningiomas en plaque originating from the sphenoid wing, who underwent surgery between 1991 and 2002. The standard surgical approach consisted of pterional craniotomy and extradural resection of any infiltrated bone. The intracranial tumor was removed, and the dura mater and bone were reconstructed. The follow-up period ranged from 6 to 118 months (mean 45.7 months).

Total macroscopic resection was achieved in 40 patients. Forty-eight meningiomas extended to the orbital roof and/or the lateral orbital wall, 34 involved the extraconal space, and eight the intraconal space. Fifty-four tumors involved the superior orbital fissure, 46 the optic canal, and 21 the inferior orbital fissure. Twelve tumors infiltrated the cavernous sinus and 27 involved the anterior clinoid process. There were no deaths in this group of patients; the rate of minor morbidity was 11.9% and the rate of major morbidity was 3%. Subtotal resections were performed in 27 patients because there was intraorbital tumor (eight patients), tumor in the cavernous sinus (nine patients), tumor beyond the tentorial notch (three patients), tumor invading the superior orbital fissure (four patients), and tumor of the skull base (three patients). Five patients underwent postoperative three-dimensional conformal radiotherapy, which resulted in stable tumor volume at follow up. Tumor recurrence was identified in seven patients (10.4%) postoperatively (range of follow up 13–47 months).

Conclusions

The goal of surgery is complete tumor removal without morbidity. An exact analysis of tumor growth and its involvement of different structures is mandatory before performing surgery.

Primary extradural meningiomas: a report on nine cases and review of the literature from the era of computerized tomography scanning

OBJECT

Primary meningiomas arising outside the intracranial compartment (primary extradural meningiomas [PEMs]) are rare tumors. To develop a better understanding of these tumors and to establish a comprehensive classification scheme for them, the authors analyzed a series of patients treated at the M. D. Anderson Cancer Center (MDACC) and reviewed all cases reported in the English-language literature since the inception of the use of computerized tomography (CT) scanning.

METHODS

Clinical records, results of radiographic studies, and histological slides were reviewed for all cases of PEM at MDACC. Demographic features, symptoms, tumor location, histological grade, and patient outcome were assessed in all cases. A comprehensive literature search identified 168 PEMs in 142 patients reported during the CT era. These reports were also analyzed for common features. Tumors for both data sets were classified as purely extracalvarial (Type I), purely calvarial (Type II), and calvarial with extracalvarial extension (Type III). Type II and Type III tumors were further categorized as convexity (C) or skull base (B) lesions. The incidence of PEMs at MDACC was 1.6%, which was consistent with the rate reported in the literature. In both data sets, the male/female ratio was nearly 1:1. The most common presenting symptom was a gradually expanding mass. The age of patients at diagnosis of PEM was bimodal, peaking during the second decade and during the fifth to seventh decades. In all MDACC cases and in 90% of those reported in the literature the PEMs were located in the head and neck. The majority of tumors originated in the skull (70%). In the MDACC series and in the literature review, the majority (67% and 89%, respectively) of tumors were histologically benign. Although fewer PEMs were malignant or atypical (33% at MDACC and 11% in the literature), their incidence was higher than that observed for primary intracranial meningiomas. Distant metastasis was not a common feature reported for patients with PEMs (6% in the literature). Outcome data were available in 96 of the cases culled from the CT-era literature. The combination of the MDACC data and the data obtained from the literature demonstrated that patients with benign Type IIB or Type IIIB lesions were more likely to experience recurrence than patients with benign Type IIC or Type IIIC tumors (26% compared with 0%, p < 0.05). The more aggressive atypical and malignant tumors were associated with a statistically significant higher death rate (29%) relative to benign tumors (4.8% death rate, p < 0.004).

CONCLUSIONS

Defining a tumor as a PEM is dependent on the tumor's relation to the dura mater and the extent and direction of its growth. Classification of PEMs as calvarial or extracalvarial and as convexity or skull base lesions correlates well with clinical outcome.

Primary meningeal fibrosarcoma: a particular neuroradiological presentation

Primary meningeal fibrosarcoma is a rare malignant tumor of the central nervous system. About seventeen cases have been reported in the literature since 1980. We present the case of a patient whose initial neuroradiological manifestation of primary meningeal fibrosarcoma was an en plaque meningioma. Fifteen months later, he developed a dramatic clinical deterioration and coma. CT scan revealed a large frontal lesion. The mass was completely removed and histological examination was characteristic of meningeal fibrosarcoma.