Cystic meningiomas. Report of seven cases

Cystic meningiomas: A complex diagnostic challenge and clinicopathological insights from a unique case presentation

Meningiomas present diverse clinical and radiological characteristics, with cystic formations constituting a lesser subset but posing significant diagnostic hurdles. We explore the complexities of cystic meningiomas through a distinctive case, highlighting the challenges in diagnosis and management due to their variable presentations. A 54-year-old female from Bengaluru, Karnataka, initially presented with transient memory disturbances. Brain MRI revealed a sizable left frontal cystic lesion exerting a mass effect and midline shift. However, rapid neurological decline led to an urgent surgical intervention via decompressive craniectomy unveiling unique intraoperative findings and with subsequent histopathological documentation of a Grade WHO 1 cystic meningioma. Cystic meningiomas present intricate diagnostic challenges resembling other intracranial lesions. Various classification systems attempt to categorize these tumors based on their imaging and histopathological characteristics. Despite this, atypical clinical manifestations often lead to misdiagnoses, necessitating a comprehensive approach to differential diagnosis. Further research is crucial to unravel the mechanisms underlying these tumors' cystic changes for improved diagnostic accuracy and tailored therapeutic interventions.

Rare clinical entity of cystic meningioma in an elderly patient: A case report and review of the literature

INTRODUCTION AND IMPORTANCE

Meningiomas, the most prevalent extra-axial neoplasm, are frequent tumors of the central nervous system that make up around 15 % of all intracranial malignancies. Although atypical and malignant meningiomas do exist, benign meningiomas make up the majority of cases. On both computed tomography and magnetic resonance imaging, a well-circumscribed, homogeneously enhancing, extra-axial mass is a typical imaging feature. An associated cyst is a rare imaging characteristic that may make it challenging to differentiate the tumor from a primary intra-axial glial neoplasm. Peritumoral edema can also lead to false positive results.

CASE PRESENTATION

A 64-year-old female patient presented to the emergency department of our hospital due to difficulty of the speech with a 3-week duration associated with unilateral headache, gait unsteadiness, and urinary incomitance. Neuroimaging of the brain by magnetic resonance imaging (MRI) with and without gadolinium contrast revealed an extra-axial cystic lesion located in the left fronto-temporal area, measuring about 4 cm × 4 cm × 4 cm. The patient underwent a craniotomy for removal of the lesion and the resected tissue was sent to pathology. Histopathological assessment revealed a pure cystic meningioma.

CLINICAL DISCUSSION

Cystic meningioma's preoperative diagnosis is not often easy to make. Compared to CT screening, brain MRI with gadolinium offers a higher diagnostic yield. To confirm the category and subtype of the tumor, a histopathological assessment of the tumor cells should always be performed.

CONCLUSION

Although its rare, cystic meningioma should be considered in the differential diagnosis of cystic brain lesions.

Intracranial cystic meningiomas: A series of six patients

OBJECTIVE

Although meningiomas are the most common primary non-glial intracranial tumors, cystic meningiomas are quite rare. This study presents six cases in order to discuss the radiological and pathological features of cystic meningiomas.

PATIENTS AND METHODS

Six patients with cystic meningiomas were included in the study. All patients underwent a cranial computed tomography scan and magnetic resonance imaging (MRI) evaluation, pre- and postoperatively.

RESULTS

All patients presented with long standing headache dating back at least two years. There was no gender predominance in our series. Radiological evaluation revealed two parasagittal and two convexity meningiomas located at the frontal region. Two lesions were located at the tuberculum sellae and the foramen magnum. All of the tumors were totally excised (Simpson Grade I or II). Pathology results included meningothelial meningioma in three patients, angiomatous meningioma in two patients, and metaplastic meningioma in one patient. In two patients, the cystic meningiomas were resected with the use of sodium fluorescein (Na-Fl) under a YELLOW 560nm microscope filter. Na-Fl was found to be very useful in demonstrating the brain-tumor interface, and it was especially effective in resecting the cyst wall of the peritumoural cystic meningiomas. None of the patients had any complications, and no recurrences were noted in any of the patients within the mean follow-up period of 51 months (range: 16-102 months).

CONCLUSION

It is important to note MRI changes specific to cystic meningioma and include meningiomas in the differential diagnosis of intracranial cystic lesions. The use of sodium fluorescein (Na-Fl) under a YELLOW 560nm microscope filter is a useful tool to differentiate the brain-tumor interface, as well as to identify the cyst wall in order to fully resect the tumor with the cystic component to avoid recurrence and achieve better clinical results.

A case report on cystic meningioma in cerebellopontine angle and recommendations for management

RATIONALE

Cystic meningioma located at the cerebellopontine angle (CPA) is an extremely rare occurrence. It is frequently misdiagnosed preoperatively. Little is known about the clinical features and outcome of this rare disease.

PATIENT CONCERNS

A 70-year-old male presenting with progressive headache and gait disturbance.

DIAGNOSIS

According to the symptoms, signs, and Gd-enhanced magnetic resonance images (MRI), a preoperative diagnosis of hemangioblastoma located in left CPA was made. Finally, the histological examination revealed a meningioma.

INTERVENTIONS

A complete resection, including the part of the solid mass together with cyst, was performed.

OUTCOMES

The postoperative course of the patient was uneventful, and no residual or recurrent tumor was found during the 24-month follow-up period.

LESSONS

Cystic meningioma should be included in the differential diagnosis of a CPA mass with atypical radiologic features, such as a large cyst and enhanced mural nodule. By summarizing the related literature, we found that the most common pathological subtype of CPA cystic meningioma is the clear cell subtype, which belongs to WHO grade II. Gross total resection including the enhanced cyst wall is extremely important. A close follow-up is necessary because of the high recurrence rate in this subset of meningioma.

Cystic Meningiomas: Correlation between Radiologic and Histopathologic Features

Background

Tumors with cysts often correlate with gliomas, metastatic tumors, or hemangioblastomas, which require differentiation.

Methods

Thirty-eight cases of cyst associated-meningioma based on preoperative radiologic studies and histologic confirmations were reviewed from November 1998 to July 2017.

Results

A total of 395 cases of meningioma were observed in the 20 years, and surgical treatment of intracranial meningioma was performed in 120 cases. Thirty-eight (9.6%) cases of cyst associated meningiomas were analyzed. Nauta type I was the most common type of cyst (39.5%) and the most frequent histopathological subtype was meningothelial type (36.8%).

Conclusion

Statistically there were no significant associations between meningioma histopathological type and associated cysts; however, the rate of World Health Organization grade II was higher in cyst associated meningiomas than in unrelated meningiomas. This correlation was weak, in accordance with the meningioma grade.

Cystic meningioma: radiological, histological, and surgical particularities in 43 patients

BACKGROUND

The presence of cysts is a rare occurrence for intracranial meningiomas in adults. We report our experience in a large consecutive series of cystic meningiomas.

METHOD

We prospectively collected data for a dedicated database of cystic meningioma cases between January 2004 and December 2011 in two tertiary neurosurgical centers. Studied data included preoperative imaging, surgical records, and pathology reports.

RESULTS

Among 1214 surgeries for intracranial meningioma, we identified 43 cases of cystic meningioma, corresponding to an incidence of 3.5 %. The most common localization was the hemispheric convexity (17/43 cases). Twenty-eight patients had intratumoral cysts, nine peritumoral, and five mixed intra and extratumoral. In 29 patients with available diffusion imaging, ADC coefficients were significantly lower in grade II-III tumors compared to grade I (p = 0.01). Complete resection of the cystic components was possible in 27/43 patients (63 %); partial resection in 4/43 (9 %); in 6/43 (14 %) cyst resection was not possible but multiple biopsies were performed from the cystic walls; in another 6/43 (14 %) the cystic wall was not identified during surgery. Cells with neoplastic features were identified within the cyst walls at pathology in 26/43 cases (60 %). All patients were followed-up for 24 months; long-term follow-up was available only in 32 patients for an average period of 49 months (range, 36-96 months). No recurrence requiring surgery was observed.

CONCLUSIONS

Cystic meningiomas are rare. Cells with neoplastic features are often identified within the cyst walls. Complete cyst resection is recommendable when considered technically feasible and safe.

A canine case with cystic meningioma showing miraculous reduction of the cystic lesion

A 12-year-old spayed female Labrador retriever was presented with forebrain signs. Brain MRI revealed a huge cystic lesion with the thickened falx in the frontal region. The brain parenchyma surrounding the lesion showed significant signs of a mass effect and also increased intracranial pressure. However, the dog suddenly became lucid after about two weeks, and an MRI scan one month after the initial study revealed a dramatically shrunken cystic lesion. The dog survived for over a year until it was euthanized for other reasons, and the brain lesion was diagnosed as a cystic meningioma histologically. To the authors’ knowledge, this is the first report that described the reduction of the cystic lesion of a cystic meningioma in dogs.

Cystic meningioma: diagnostic difficulties and utility of MRI in diagnosis and management

We report the case of a patient presenting with convulsions in the emergency department. A CT examination revealed a mixed solid and cystic frontal peripheral mass. The intra-axial or extra-axial location and the differentiation between primary or secondary origin were not evident so MRI was performed. The most probable diagnosis was cystic meningioma with intratumoural cysts. Based on MRI findings, the neurosurgeon resected the mass together with its cystic components. The histological report verified the diagnosis and the patient had an excellent outcome.

Cystic meningioma simulating arachnoid cyst: report of an unusual case

The purpose of this paper is to show an unusual case of meningioma simulating arachnoid cyst on CT scan and MRI, diagnosed in a 63-year-old woman evaluated for headache and vision disorders. The meningioma shown is predominantly cystic with a small mural nodule enhancing after gadolinium and exhibiting diffusion restriction. Cystic portion of the tumor is hypodense on CT, and evidences fluid signal intensity on T1- and T2-weighted MR imaging.

Do aggressive imaging features correlate with advanced histopathological grade in meningiomas?

Atypical and malignant meningiomas are more likely to recur than benign meningiomas. We aimed to distinguish atypical and malignant meningiomas from benign meningiomas based on imaging findings. Between 2004 and 2007, a total of 75 patients with resected intracranial meningiomas were retrospectively reviewed. Histopathological grades were assigned as benign and atypical/malignant meningiomas according to the World Health Organization (WHO) classification. All patients received preoperative CT scans and MRI studies. Six aggressive imaging features were evaluated and compared between the two groups: (i) intratumoral cystic change; (ii) hyperostosis of the adjacent skull; (iii) bony destruction; (iv) extracranial tumor extension through the skull base foramina; (v) arterial encasement; and (vi) peritumoral brain edema. There were 59 benign and 16 atypical/malignant meningiomas. Only intratumoral cystic change and extracranial tumor extension through the skull base foramina were more prevalent in atypical/malignant meningiomas (p=0.001). Hence, these two imaging features might be potential markers of atypical/malignant meningiomas.

MRI findings of intracranial cystic meningiomas

AIM

To report the magnetic resonance imaging (MRI) features of intracranial cystic meningiomas and compare these features in intra- and peritumoural cyst groups.

MATERIALS AND METHODS

Fourteen cases of peritumoural cystic meningiomas were compared with 18 cases of intratumoural cystic meningiomas. All patients were examined using non-enhanced and contrast-enhanced MRI. Tumour location, tumour size, signal intensity, enhancement characteristics, and cystic changes were assessed. The MRI features were compared between the intra- and peritumoural cyst groups.

RESULTS

Most cystic meningiomas comprised two or more cysts. The solid parts of the tumours showed moderate or marked enhancement after the injection of contrast material. An enhanced cyst wall was found in six out of 14 cases in the peritumoural cyst group, but not in the intratumoural cyst group. Peritumoural cystic meningiomas were predominately located in the cerebral falx, whereas the intratumoural cystic meningiomas were predominantly found in frontal convexity (X(2)=7.434, p=0.024). The cysts were larger in the peritumoural cyst group than in the intratumoural cyst group (t=5.274, p=0.0258). Peritumoural oedema was more commonly found in the intratumoural cyst group (X(2)=6.863, p=0.008). Cystic meningiomas with solid parts located inside the cyst are reported for the first time.

CONCLUSION

Cystic meningiomas, although uncommon, should be differentiated from other cystic intracranial lesions. Peri- and intratumoural cystic meningiomas have distinct MRI features. The present study provides the first report of two lesions with solid parts located inside the cyst, as well as one lesion with a calcified solid nodule and haemorrhage within the cyst.

Cystic meninigioma

To study the clinical characteristics of cystic meningiomas, we analyzed retrospectively 21 patients with cystic meningiomas and reviewed the literature with regard to clinical presentation, imaging features, preoperative diagnosis, surgical findings, and histopathological results. The cysts were classified into intratumoral and peritumoral cysts based on their relationship to the tumor, and also according to the classification method described by Nauta. For the 21 patients in our group, there were seven peritumoral cysts and 14 intratumoral cysts. Various pathophysiological mechanisms contribute to the formation of cystic meningiomas. The diagnosis of cystic meningiomas based on CT scan can be problematic, and differentiation from glioma or metastasis may be difficult. MRI scans show low signal intensity areas within the mass on T1-weighted images and high signal intensity areas on T2-weighted images, and the solid parts of tumors are contrast-enhanced after gadolinium administration. MRI with gadolinium enhancement dramatically increases the diagnostic accuracy for cystic meningiomas and provides critical information for their surgical care. Total surgical resection of cystic meningioma is ideal, but special attention should be paid to the cyst walls.

Clinical and histopathological analysis of cystic meningiomas

Between 1993 and 2003, we treated 21 patients with cystic meningioma (of 365 with meningioma, 5.5%). We grouped these patients according to classifications by Nauta and Rengachary and analyzed them by gender, age, tumor location, clinical manifestations, MRI features and histopathology. The mean duration of symptoms was relatively short at 1.6 months. There were five atypical and 16 benign meningiomas on histopathology. In type I and II cystic meningiomas, with intratumoral cysts, all cyst walls enhanced on MRI and had tumor cells in the cyst wall on histopathology. In type III and IV cystic meningiomas, with peritumoral cysts, the cyst wall did not enhance on MRI and only one case (type III) had tumor cells in the cyst wall on histopathology. We suggest that when the cyst wall shows contrast enhancement on imaging, the cyst wall should be completely removed at surgery. If there is no contrast enhancement, multiple biopsies of the cyst wall should be taken to assess the presence of tumor cells in the cyst wall.

Atypical Meningioma With Large Cyst-Case Report-

A 29-year-old male presented with loss of consciousness and generalized seizure, followed by right hemiparesis and speech disturbance. Computed tomography and magnetic resonance imaging showed a solid, enhanced tumor with a cyst in the left frontal area with surrounding edema and mild mass effect. The cyst wall was also enhanced. The preoperative diagnosis was cystic falx meningioma. The tumor was totally resected, but most of the cyst wall adhered tightly to the surrounding brain and could not be removed. Histological examination revealed atypical meningioma and tumor cells in the cyst wall. The patient received local radiotherapy to the residual cyst wall with a total dose of 50 Gy.

Magnetic resonance imaging and diffusion-weighted images of cystic meningioma

BACKGROUND AND PURPOSE

Cystic meningiomas are quite rare, accounting for between 2% and 4% of all intracranial meningiomas. To better understand all the types of cystic meningiomas with magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI) and histopathology, we attempted to correlate the MRI and DWI features of cystic meningiomas with the histopathological findings.

METHODS

We collected 15 cases of cystic meningiomas diagnosed between 1993 and 2000 (5 men and 10 women, 41-80 years old). Fifteen patients had conventional MRI and 14 patients had CT scan. DWI was also performed in three patients. Apparent diffusion coefficient (ADC) images were also done. In the classification of cystic meningiomas, we adopted Worthington's classification, which divides cystic meningiomas into five groups.

RESULTS

Tumor resection was performed in all patients. Tumor locations were as follows: convexity (10), falx (2), pterion (2) and lateral ventricle (1). Regarding the types of cystic lesion, type I (3), type II (3), type III (3), type IV (1) and type V (5) were found. Histopathologically, there were six atypical, four meningothelial, two malignant, one fibroblastic, one angiomatous and one transitional. Intratumoral cystic meningiomas were more common in atypical types. Peritumoral cystic meningiomas were more common in meningothelial and atypical types. The cystic portion of the three cystic meningiomas was hypointense or mildly hyperintense on DWI. ADC ratio (ADCR) of DWI for cyst part of two type I cystic meningiomas was 1.25 and 0.82; for cyst part of one type III was 4.04.

CONCLUSIONS

It is important to recognize the neuroimaging features of the cystic meningiomas. Conventional MRI and DWI may play an important role in the preoperative radiological evaluation and the recognition of these types of cysts for proper surgical treatment.

Suprasellar cystic meningioma: unusual presentation and review of the literature

We report on a case of suprasellar cystic meningioma. The magnetic resonance imaging of this tumor resembled that of a craniopharyngioma. The definitive diagnosis of meningioma was made only after histopathological confirmation. We conclude that preoperative studies are often equivocal. The possibility of meningioma should be considered in the diagnosis of any intracranial neoplasms with radiological and surgical evidence of a cystic lesion.

Intracerebral cyst associated with meningioma

A 27-year-old male had experienced an episode of severe headache and nausea, sometimes accompanied by an inability to name objects. Magnetic resonance imaging showed a huge cyst within the left temporal lobe and a high degree of brain shift by it. A small round mass, which appeared to be a mural nodule, was located in the tip of left middle fossa. It was highly enhancing together with its attached dura mater, but the cyst wall was not enhanced. Sphenoid ridge meningioma with an associated intracerebral cyst or cystic glioma invading the dura mater was suspected. During surgery the small tumor was found to be arising from the sphenoid ridge and evaginating into the tip of the temporal lobe. The intracerebral cyst had a smooth surface and the tumor was visible outside the cyst through its wall. The tumor was totally removed, but the cyst wall was left without excision. Postoperatively he had no symptoms. Histological examination showed a microcystic meningioma. It is stressed that differentiations of cystic meningiomas from other cystic tumors and, of intratumoral from extratumoral cystic meningiomas using radiological, operative or histological findings are important.

Cystic meningiomas resembling glial tumors

BACKGROUND

Meningiomas can be associated with peripheral or intratumoral cysts. Meningiomas with intratumoral cysts, also called "true cystic" meningiomas, are rare and can frequently be confused with glial or metastatic tumors.

METHODS

We report three cases of "true cystic" meningiomas and discuss the preoperative evaluation, etiology, and surgical treatment of these cystic lesions with reference to the literature.

RESULTS

Magnetic resonance imaging (MRI) and computed tomography (CT) studies usually display a cystic lesion close to the dura with or without enhancement of the cyst wall. Multiplanar MRI scans are very useful to show the presence of a solid tumor or some dural enhancement. Some cases of "true cystic" meningiomas however, are still erroneously preoperatively diagnosed. Complete surgical removal of the tumors and of the entire cyst wall was performed in our cases. Despite the absence of a typical ring enhancement of the cystic lesion in two cases, histopathologic studies displayed the presence of tumor cells on the cyst wall of both cases.

CONCLUSIONS

Tumor cells can be present on the cyst wall and therefore can be one of the causes of tumor recurrence if not totally removed. Accurate preoperative radiologic diagnosis (multiplanar MR images) and intraoperative histopathologic studies are fundamental in that they will definitely influence the surgical strategy and outcome.

Cystic meningiomas in children: a diagnostic challenge

Two cases of cystic meningioma in children are presented. The MR imaging features of each case presented difficulties in differential diagnosis because of the cystic nature of the neoplasms and their location. Cystic areas in meningiomas are encountered more frequently in children than in adults. Meningioma must be included in the differential diagnosis of cystic intracranial tumors in children.

Cystic meningioma

Meningiomas are usually solid tumours. Cystic changes in meningiomas are rare. These cysts may occur extratumoural, peritumoural or intratumoural. Diagnostic difficulties arise in cases of cystic meningiomas. Nine cases of cystic meningiomas were operated on in the past 6 years at the department of neurosurgery University of Alexandra. The mean age of patients was 46.2 years. Male to female ratio was 1/2. Less oedema was observed in extratumoural cysts, and more oedema in intratumoural cysts. The fluid contained was dark brown or dirty yellow in intratumoural cysts (type C), xanthochromic in peritumoural cysts surrounded by tumour tissue (Type B), or clear fluid in extratumoural cysts (Type A). Based on these two observations it is proposed that the cyst fluid and peritumoral oedema may represent variable degrees of degeneration or secretion by tumour cells. Pre-operatively diagnostic criteria are presented.

Meningioma in children: a report of nine cases and a review of the literature

BACKGROUND

Meningioma is a common tumor of the central nervous system in adults, accounting for 10%-20% of all primary intracranial tumors. It is rare in children, with an incidence of 2.19% (0.85%-2.3%). Although there are numerous case reports in the literature, no firm conclusions can be drawn. For this report we accumulated, reviewed, and analyzed reports in the literature from 1960-93.

METHODS

A total of 318 patients with meningioma were managed in King Faisal Specialist Hospital and Research Centre from 1981-93. Nine of these patients (2.8%) were children aged 16 years or less. These cases were analyzed retrospectively with regard to age, sex, clinical presentation, radiologic finding, pathologic findings, management and outcome.

RESULTS

Childhood meningioma represented 2.8% of all meningioma cases and 2.2% of all central nervous system tumors seen in children. There were six males and three females. The average age at presentation was 10.1 years (range 1-16 years). There were four cases of meningioma in the orbit an one each in the temporal region, foramen magnum, tentorial region, subfrontal base, sellar region and ethmoidal air sinus. There were two cases of multiple meningioma. Meningothelial meningioma was the type most frequently seen.

CONCLUSION

Meningioma is rare in children and males are affected more than females. Tumor locations that are rare in adults are more common in children. The meningothelial type is most frequently seen. Prognosis is poor compared with that in adults, as the tumors tend to grow more rapidly and to a larger size, undergo malignant changes, and have a greater rate of recurrence. Whenever feasible, every effort should be made to achieve total resection of the tumor at the first attempt. If radiation therapy is used in children it should be limited to those who have recurrent tumors so as to minimize organic and psychologic complications.

Cystic meningiomas

BACKGROUND

Meningiomas are generally solid tumors and are easily diagnosed by CT scans and MRI scans. Rarely are these tumors associated with cysts that can cause a confusion in the pre- and intraoperative diagnosis. Cysts associated with meningiomas may be intratumoral or peritumoral.

METHODS

The authors conducted a retrospective study of the seventeen meningiomas, out of a total number of 232, which were associated with cysts. The cysts were classified based on their relationship to the tumor. The patients' sex, age group, location of the tumor, and pathological type of tumor were also analyzed.

RESULTS

The 17 cases of cystic meningioma formed 7.3% of the meningiomas seen between 1984 and 1993. Eleven of these were intratumoral and 6 peritumoral. One case had both intra- and peritumoral cysts. The tumors were found mostly in the fourth and fifth decades of life. Histologically, all the peritumoral cysts except one were associated with meningotheliomatous meningiomas. Tumors with peritumoral cysts were more common in males. Intratumoral cysts, more common in females, were angioblastic or meningotheliomatous on histopathology. Only one case was an anaplastic meningioma.

CONCLUSION

Cysts associated with meningiomas, although uncommon, are certainly not rare. The peritumoral and the intratumoral cysts form distinct subtypes needing separate consideration. Cystic meningiomas are only rarely malignant.

Cystic meningiomas: a review

Cystic meningiomas are uncommon tumors that are easily confused with metastatic or glial tumors that have cystic components. We have retrospectively reviewed all of the meningiomas operated on at the University of Puerto Rico in a 5-year period (1989-1993) and found only five cystic meningiomas (4.3% of total meningiomas). There is still debate about the etiology of the cyst wall; thus, multiple biopsies and frozen sections are recommended. Magnetic resonance imaging has improved diagnostic accuracy with its ability to demonstrate the dural attachment of the tumor.

Meningiomas

This article reviews the recent literature on the pathogenesis and pathology of meningiomas, contemporary techniques of surgical resection, and new nonsurgical treatments, including radiation and hormone therapy. Factors predisposing to meningioma formation include female sex, previous ionizing radiation, and Type 2 neurofibromatosis. The first factor may act through the expression of sex hormone receptors, especially the progesterone receptor, in these tumors; the other two probably act by causing a deletion on Chromosome 22. The pathological classifications of meningiomas include the traditional division into histological subtypes and the World Health Organization classification that selects characteristics that may lead to recurrence. There is an increasing emphasis on proliferative indices and other characteristics that may predict aggressive behavior in these tumors. On computed tomography, meningiomas are enhancing, well-marginated, dural-based lesions that may have considerable surrounding edema; the cause of the edema is uncertain but may result from secretory products of the tumor. Magnetic resonance imaging with enhancement will demonstrate these lesions accurately and can be used for three-dimensional reconstruction as well. Computed tomography and magnetic resonance imaging have largely replaced angiography in the preoperative diagnosis of meningiomas, but angiographic embolization may be a useful operative adjunct. Although meningioma surgery is sometimes thought of as benign and curative, the reported surgical mortality rate is as high as 14.3% and the reported 10-year survival rate after surgery varies from 43 to 77%. Surgery has advanced most in the management of suprasellar, cavernous sinus, clivus, tentorial, and posterior fossa meningiomas, because new approaches and a better understanding of anatomy have allowed more radical resection. There is still substantial morbidity associated with surgery in these regions, however, and the long-term recurrence rates are still unknown for these new radical techniques. For convexity, parasagittal, lateral sphenoid wing, and olfactory groove meningiomas, complete resection should be the goal and operative morbidity appears to be low. There is a high recurrence rate after surgery. With apparent total removal, the recurrence rate varies from 9 to 20% at 10 years, with subtotal resection varying from 18.4 to 50%. The degree of resection appears to be most important in recurrence, but histopathological features are also important. Recently, radiation therapy has been recognized as a useful adjunct to surgery, and with radiosurgical techniques may become more important in the future. Antiprogesterone therapy appears to have had some success as well, and it or other hormonal therapy may be another future option for residual or recurrent meningiomas.

Magnetic resonance imaging and pathological correlates of meningiomas

We examined the relationships between specific magnetic resonance imaging features and certain gross and microscopic characteristics of meningiomas, including vascularity, gross texture (consistency), and venous sinus involvement. Magnetic resonance imaging scans, surgery reports, and the histopathological findings of tumors were examined retrospectively in 54 patients. Sinus involvement was accurately predicted on T1-weighted images in 9 of 10 cases (P = 0.001) and tumors with cystic changes in 3 of 3 cases. T1-weighted images were not useful for predicting vascularity unless actual flow voids could be visualized (five of six cases). There was no correlation between T1 signal intensity, tumor consistency, or histological findings. In tumors without detectable vascularity on T1-weighted images, hyperintensity relative to gray matter on T2-weighted images was correlated with increased vascularity (P = 0.004). Tumors with soft consistency (P = 0.007), cellular atypia, invasion, angioblastic, or melanocytic components were also hyperintense, compared with gray matter on T2-weighted images (P = 0.0266). Aggressive meningiomas were found to be more vascular (P = 0.045). No correlation was found between the degree of surrounding edema or contrast enhancement with histopathological findings, vascularity, or consistency.

Cystic meningioma: report of three patients

Three patients with cystic meningioma are reported. The computed tomographic scans or magnetic resonance images of these tumors resembled those of a glial or metastatic tumor with cystic or necrotic changes. There is no definitive method for preoperatively differentiating cystic meningiomas from the more common malignant glioma. Angiographic evaluation and collaboration with a neuropathologist are important for the recognition of these potentially curable neoplasms.

Cystic meningiomas

Five cases of meningiomas associated with cysts are reported. In a review of the literature the authors stress the importance and difficulty of the preoperative accurate diagnosis and the differential diagnosis from other cystic tumours to avoid misdiagnosis.

Cerebral meningiomas in children

Cerebral meningiomas are rare tumors in children that represent 1.4% of CNS tumors and 1.5% of intracranial meningiomas. We have analyzed 197 cases of cerebral meningiomas under 16: 178 cases were taken from the available literature and 19 from our series. When comparing pediatric meningiomas with those of adults, we noted some differences. Before the age of 16 there is a slight preference for males; the intraventricular variety is more frequent; cystic meningiomas and the absence of dural attachment are more frequent findings; the neuroradiological diagnosis is more difficult.

Paediatric intracranial meningiomas

Intracranial meningiomas are rare before the age of 16 years. Of 1397 intracranial meningiomas operated on by our service up to 1987, 19 (1.3%) were diagnosed before this age. In the literature accessible to us we have found another 274 cases. An analysis of the literature shows that intracranial meningiomas in paediatric patients differ from those in adults in the following respects: a slight predilection for males, a high frequency within the ventricular system, more frequent presence of intra- and peri-lesional cysts and more frequent absence of dural attachment. In addition, the neuroradiologic diagnosis of nature is more difficult in paediatric patients.

Cystic changes in intracranial meningiomas. A review

A survey on cystic meningiomas is given based upon the analysis of 85 cases in the literature and an additional three of our own. In these three cases the computerized tomography appearance led to an incorrect preoperative diagnosis of necrotic glioma or metastatic lesion. The tumours were totally removed and the definitive diagnosis of meningioma was histologically confirmed. In reviewing the literature, we found 85 cases of intracranial meningiomas with cystic changes reported. Their pathological and radiological findings are discussed.

Cystic meningiomas

Twenty-two cases of unusual intracranial meningioma associated with a cyst are reported and 144 published cases reviewed. The complex mechanisms leading to the formation of the cyst within the meningioma are analyzed on the basis of the surgical and histopathological evidence. The neuroradiological features (Computed Tomography and Angiography) which supply a correct preoperative diagnosis are discussed. It is clear from the literature how difficult preoperative diagnosis is, being possible only in 38% of cases with CT scanning and in 13% with angiography. It is necessary to remove not only the solid portion of the meningioma but also the cyst wall in order to prevent a recurrence. This is technically difficult for the type II intratumoural variety of Nauta's classification.

CT-findings in cystic meningiomas

Cystic meningiomas are rare, about 10% occurring in children. Only 61 cases have been reported in the literature. Based on 6 of our own cases and the reports in the literature typical CT-findings are described and differentiating features from other cystic mass lesions discussed. If a tumour on CT shows a cystic component, is smoothly outlined, enhances markedly and is attached to the dura, then a preoperative diagnosis of cystic meningioma should be taken into account. This holds especially true if the patient is a child.

Intraventricular meningioma. A review of 10 cases of the National Hospital, Queen Square (1974-1985) with reference to the literature

Ten patients with histologically verified intraventricular meningiomas were treated between 1974 and 1985. There were eight female and two male patients, ranging in age from 25 to 72 years with a mean age of 45.5 years. Headache and disturbed mentation were the most common presenting symptoms whereas corticospinal disturbance, altered mentation and homonymous hemianopia were the most common signs on formal neurological examination. Papilloedema was demonstrable in 50% of cases and evidence of dysphasia was apparent in 60% of patients with lesions affecting their dominant hemisphere. A single instance of drop attack occurred in a patient harbouring a third ventricular meningioma. Computed tomography, with and without contrast enhancement, and angiography were employed in all cases and proved highly sensitive and specific for tumour localisation and tissue diagnosis. In addition, angiography proved invaluable in demonstrating both vascular supply and the effects imposed upon the surrounding cerebral vasculature by tumour mass and hydrocephalus. Nine tumours occurred in the lateral ventricular trigone of which 5 were left-sided. A tenth tumour was located in the third ventricle. Twelve resections were performed in 10 patients. One patient was found to have a highly malignant cystic meningioma which recurred within 10 weeks of the original surgery and proved fatal shortly thereafter. A second patient whose initial resection was subtotal had a recurrence 3 years postoperatively which was totally resected. Lesions were approached most commonly through the posterior middle or posterior inferior temporal gyri. On 3 occasions a right posterior middle frontal gyrus approach was used and in one case a posterior parieto-occipital cortical incision was employed.(ABSTRACT TRUNCATED AT 250 WORDS)