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: neuroradiological (MRI, CT) and macroscopic intraoperative appearance. A case report

Differential diagnosis of intracranial cystic meningiomas may present difficulties in about 10-15% of cases where anatomo-pathological alterations such as intratumoral necrosis, cystic cavity, hemorrhage or lipomatous infiltration are present. These alterations are responsible for an unusual radiological appearance which may suggest a false diagnosis. We describe a case of meningioma with a cystic appearance in which MRI was more helpful than CT, because it suggested an extra-axial meningiomatous lesion and thus allowed more precise surgical planning.     

Acrodermatitis enteropathica-like rash and enterocolitis

Primary intracranial melanomas are rare and occur mainly in young adults. Originating from leptomeningeal melanoblasts and extending into the parenchyma, the tumours closely resemble meningiomas, from which they are radiologically difficult to distinguish despite progress in neuroimaging. Definitive diagnosis is usually made on histopathological examination, though confirmed only after post-mortem examination in some cases. Prolonged disease-free periods, and in rare cases long-term survival, are possible following successful total surgical excision. This case presented with typical clinical features but, at 79 years old, an unusual age.     

Upregulation of 5''-AMP-activated protein kinase is responsible for the increase in myocardial fatty acid oxidation rates following birth in the newborn rabbit

Eighteen patients with intracranial skull base tumours diagnosed at CT or MR as neuromas or meningiomas were studied with positron emission tomography (PET) using L-(methyl-11C) methionine. Compared with normal cerebellar tissue, the uptake of methionine in the tumours increased more rapidly and reached a higher level, and showed a slow decline after a peak occurring about 5 min after the injection. All the meningiomas exhibited considerably higher accumulation of the tracer compared with the surrounding cerebellar tissue, which made the tumour easy to identify and to demarcate from the surrounding cerebellar tissue, which made the tumour easy to identify and to demarcate from the surrounding structures (tumour to cerebellum ratios 2.62-5.37, mean 3.63). The uptake was homogeneous in all meningiomas, which were all of the syncytial type. The neuromas showed lower contrast against the cerebellum (tumour to cerebellum ratios 1.1-1.87, mean 1.48). Some neuromas displayed an irregular pattern with regions of decreased tracer uptake corresponding to small cystic areas within the neuroma. There was no overlap in methionine uptake between the two tumour groups. The results indicate that PET-methionine may contribute to the evaluation, treatment planning and follow-up of patients with skull base meningiomas and neuromas.     

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.     

Radiation-induced intracranial meningiomas

Based on the analysis of 112 cases a clinical characterization has been done of intracranial meningiomas developed secondary to X-ray irradiation of the head for fungus disease of skull integuments. X-ray irradiation increases the risk of intracranial meningioma development up to 4-fold. Radiation-induced intracranial meningiomas are characterized by particular features of clinical manifestations, by preponderance of hyperdense forms, by being of large size, as well as by a high frequency of changes in the adjacent bone presenting as hyperostosis, usuration, and destruction. The above meningiomas are notable for a high specific weight of anaplastic varieties.     

A case of thoracic meningioma presenting paraplegia at 4.5 years after removal of a falx meningioma

A case of a thoracic meningioma presenting paraplegia 4.5 years after removal of a falx meningioma is reported. A 73-year-old woman, complaining of diplopia, was admitted to our department. Neurological examination revealed right abducens palsy. CT demonstrated a well-enhanced right frontal mass beneath the falx. The mass was totally removed under right frontal craniotomy. Its histology was transitional meningioma with rich fibroblasts. 4.5 years after craniotomy, she complained of progressing gait disturbance and nocturnal leg pain. Neurological examination revealed paraplegia, complete loss of leg sensation, loss of patellar and ankle reflex, bilateral positive Babinski reflex and urinary disturbance. Rectal function and anal reflex were preserved. Thoracic MRI demonstrated an intradural extramedullary mass which was well enhanced with Gd-DTPA at Th6-7. Under laminectomy, the mass was totally removed. Its histology was transitional meningioma with rich psammoma bodies and whirl formations. 4 months after removal, her palsy and sensory loss were almost completely recovered. We were able to find 15 cases of combined intracranial and spinal meningiomas in the literature. A young woman of neurofibromatosis suffered from tentorial, intraventricular and C1-2 meningiomas. Of 15 cases without neurofibromatosis including our case, 4 cases were of young boys and 11 cases were of women. Their initial symptoms originated from intracranial meningiomas in 8 cases. Multiple intracranial meningiomas were revealed in only 4 cases. In 9 cases, one case presented a combination of one intracranial meningioma and one spinal meningioma. Histology of intracranial meningioma was almost the same that of spinal meningioma in almost half of the 10 cases. These findings suggest the multi sentricity theory of multiple meningiomas originating in other neuroaxial compartments. Severe spinal dysfunction was recovered after removal in our case. Rectal function and anal reflex were preserved. These anorectal findings suggest that spinal dysfunction is either complete or incomplete. Motor evoked potentials are hopeful tools which can select reversible spinal motor dysfunctions.     

Cytogenetic analysis of aggressive meningiomas: possible diagnostic and prognostic implications

BACKGROUND: Published karyotypes from aggressive (atypical and malignant) meningiomas are few, but suggest clonal evolution from benign tumors with monosomy 22 to aggressive forms with additional abnormalities. The goal of this study was to identify the most frequent karyotypic abnormalities associated with aggressive histopathology and biologic behavior. METHODS: Eight intracranial meningiomas exhibiting histologically atypical features at the time of intraoperative diagnosis were chosen for cytogenetic analysis. The study set was comprised entirely of histologically atypical meningiomas. Four were considered malignant; three on the basis of brain invasion and one due to extracranial metastases. None was histologically anaplastic. RESULTS: Chromosomal abnormalities were demonstrated in 6 cases (75%), 5 of which were complex (63%). Loss of chromosome 22 was identified in two cases, both of which were associated with additional aberrations. Abnormalities most frequently involved chromosomes 1 (63%), 3 (50%), and 6 (63%). Four cases (50%) had dicentric or ring chromosomes. An additional 47 previously reported karyotypes from atypical and malignant meningiomas were reviewed. Comparison with published karyotypes of 200 histologically benign meningiomas served to underscore the increased frequency of complex karyotypes, chromosome 1, 3, and 6 abnormalities, and telomeric associations in the aggressive tumors. Apparently normal karyotypes as well as monosomy 22 alone were more frequently associated with benign, nonatypical histopathology. CONCLUSIONS: These findings suggest a possible role for cytogenetic analysis in determining the prognosis and perhaps in refining the diagnosis of atypical or aggressive meningiomas. Further studies are necessary to determine the significance of complex karyotypes, chromosome 1, 3, and 6 abnormalities, and telomeric associations, particularly whether they portend a more aggressive clinical course in meningiomas lacking features of histologic atypia.     

Neurocysticercosis in children: clinical and radiological analysis and prognostic factors in 54 patients

INTRODUCTION AND MATERIAL: We studied 54 patients younger than 17 years of age with neurocysticercosis to determine the clinical manifestations, neuroimaging findings, and prognostic factors of this condition. RESULTS: Seizures were present in 48 patients, representing the most common clinical manifestation. Forty-eight patients had a normal neurological examination, and only 3 patients had clinical evidence of increased intracranial pressure. CT scan of the brain revealed parenchymal brain cysticerci in 52 patients; one patient had a pure subarachnoid form of the disease and the remaining patient had a mixed (subarachnoid and parenchymal) form. The most common CT finding in patients with parenchymal neurocysticercosis was a single colloidal cyst (19 cases). All patients with seizures were treated with anti-epileptic drugs with an excellent rate of seizure-control. In addition, 23 patients received albendazole that caused resolution of cystic lesions in 19 cases. Anti-epileptic drugs were withdrawn in 13 patients who remained free of seizures during two years. However, 9 (69%) of these patients had recurrent seizures. CONCLUSION: This evidence is in contrast with the reported benign course of neurocysticercosis in children, since most patients had seizure relapses despite therapy.     

Combined neck dissection and postoperative radiation therapy in the management of the high-risk neck: a matched-pair analysis

PURPOSE: Our purpose was to determine the sensitivity, specificity, and receiver operator characteristic (ROC) curve of a fast screening MR protocol in children and adolescents with suspected intracranial tumors. METHODS: One hundred forty-one patients (mean age, 9.7 years; range, 2 months to 23.5 years) with suspected brain tumor were entered in a case-control study. Eighty-seven patients had intracranial tumors (31 suprasellar/hypothalamic, 27 supratentorial, 26 infratentorial, and three pineal) and 54 patients in the control group had other disorders. Two neuroradiologists reviewed blindly a detailed three-sequence conventional protocol (acquisition time, 8 minutes 27 seconds) and a two-sequence fast screening MR protocol (acquisition time, 4 minutes 44 seconds). RESULTS: Sensitivity and specificity of the fast screening protocol for intracranial tumors was 100% and 92.6%, respectively. The areas under the ROC curves were 0.966 for the fast screening and 0.980 for the conventional MR protocol. No diagnostic performance difference was found between the ROC curves using the Az index. A kappa statistic of .93 for both examinations indicated excellent interobserver agreement. Additional MR sequences and other neuroimaging studies were not deemed necessary to exclude the presence of an intracranial tumor. CONCLUSION: A fast dual-plane brain MR protocol may be adequate to screen children and adolescents thought to have an intracranial tumor. The less than 5 minute acquisition time allows a complete examination (including preparation) to be performed in 10 to 15 minutes. Future studies are recommended before this time-efficient neuroimaging examination is incorporated into clinical practice.     

The role of neuroimaging in the initial management of patients with minor head injury

STUDY OBJECTIVE: To determine whether omitting neuroimaging in the primary assessment of patients with minor head injuries in the emergency department is safe. DESIGN: Prospective cohort study. SETTING: University hospital, Copenhagen County Hospital, Glostrup, Denmark. PARTICIPANTS: The study group consisted of 2,204 patients presenting to the ED after sustaining minor head injuries. Only patients able to talk and walk were included. MEASUREMENTS AND MAIN RESULTS: The decision to admit was based exclusively on clinical guidelines in which the findings in the ED were of highest priority. Seven patients (0.3%) had a skull radiograph; computed tomography was not used in the primary evaluation. Four hundred thirty patients (19.5%) were admitted. After hospitalization, four patients developed intracranial complications. One required surgery, two required hyperventilation, and one was observed. Follow-up demonstrated that no patient with an intracranial complication had been missed. CONCLUSION: We found it safe to exclude neuroimaging in the primary assessment of patients with minor head injuries in the ED, and to rely instead on clinical criteria.     

Meningiomas of the temporal bone

Meningiomas should be considered in the differential diagnosis of otologic tumors arising from the middle ear and mastoid. It is generally recognized that meningiomas may invade the temporal bone via direct extension from the intracranial space (secondary). It is not generally recognized that meningiomas can develop initially in the middle ear cleft (primary). Representative cases of primary and secondary meningiomas of the temporal bone are described and clinical aspects of diagnosis surgical management are discussed. In order to assess the pathogenesis of meningiomas of the temporal bone, histological studies were done on 200 temporal bone specimens. In certain specimens, ectopic arachnoid granulations, from which primary meningiomas may originate, were identified and described, according to location. One specimen was most unusual in that it contained ectopic glial as well as arachnoidal tissue.     

Effects of gamma knife radiosurgery for brain tumors: clinical evaluation

BACKGROUND: Gamma knife radiosurgery is a safe and effective alternative to microsurgery in the management of selected intracranial lesions. In our initial three-year experience with gamma knife radiosurgery, 431 patients were treated using this method. This report presents the treatment results for three different types of brain tumors: benign meningiomas, malignant metastases and gliomas. METHODS: A retrospective study was performed to analyze a consecutive series of 71 meningiomas, 31 metastatic tumors and 21 gliomas treated by gamma knife radiosurgery between March 1993 and May 1996. The treatment results were investigated using regular magnetic resonance examinations and tumor volume measurement at six-month intervals to observe sequential changes of the tumors. Patients with meningiomas were further divided into three groups according to the peripheral radiation doses: high-dose (20-17 Gy, n = 18), medium-dose (16-15 Gy, n = 33) and low-dose (14-12 Gy, n = 20). The Generalized Estimation Equation was applied to compare treatment results in these three groups with different doses and tumor volumes. RESULTS: Volume measurements of the 71 meningiomas showed that 76% decreased in size, 16% stabilized and 8% increased in size. The volumes increased most frequently in the early stage (6-12 months) after treatment and subsequently regressed after the twelfth month. The tumor control rate for meningiomas in our three-year follow-up was over 90%. For meningiomas, the statistical analysis showed that both the radiation dose and tumor volume were significantly related to the development of adverse radiation effects (p < 0.05). In metastatic tumors, rapid tumor regression after radiosurgery was found in 87% of the patients. In gliomas, radiosurgery effectively inhibited tumor growth in selected patients with small, circumscribed, less infiltrative tumors. Ependymomas and low-grade astrocytomas had more favorable outcomes than other gliomas. CONCLUSIONS: Gamma knife radiosurgery is effective for controlling tumor growth in benign meningiomas for up to three years after surgery. In selected cases of malignant metastasis and gliomas, most patients appeared to benefit from the treatment with symptomatic improvement and prolonged survival. Treatment strategy and dose selection in radiosurgery should be adjusted to optimize tumor control and avoid adverse radiation effects.     

The pattern-evoked potential in compression of the anterior visual pathways

Pattern evoked responses have been recorded in 19 patients with compression of the optic nerve, chiasm or tract, verified at operation. These included 4 patients with orbital tumours, 5 with intracranial meningiomas, 2 with craniopharyngiomas and 8 with pituitary tumours. The evoked response was abnormal in all except one of these patients. The pattern of abnormalities in the response, however, differed from that in the earlier series of patients with primary demyelinating disease. The incidence of delayed responses was much lower, and the magnitude of the delays was smaller. Absent responses were particularly characteristic of patients with intracranial meningiomas. Tumours arising in the region of the sella turcica were associated with a high incidence of abnormalities of the waveform of the response, and asymmetry of the field of the occipital evoked potential was especially characteristic of this group. Most, but not all, asymmetric cases were associated with field defects.     

Perceptual similarity of shapes generated from Fourier descriptors

BACKGROUND: Growth rates and tumor aggressiveness of meningiomas are thought to be closely related to brain edema development. However, histopathologic data alone are not consistently accurate predictors of the behavior and clinical course of a meningioma. METHODS: The authors examined 57 histologically proven intracranial meningiomas to identify factors, including growth fractions determined by MIB-1 immunostaining, that may influence the development of meningioma-associated peritumoral brain edema. There were 54 benign, 2 atypical, and 1 anaplastic meningiomas. The MIB-1 staining index (SI) percentage was defined as the number of MIB-1 positive cells divided by the total number of tumor cells in a 1.037-square millimeter area on the slide. The extent of peritumoral brain edema was determined using preoperative magnetic resonance imaging. The extent of edema was classified as Grade 0,1, or 2 (GR0, GR1, or GR2), in order of increasing severity. RESULTS: The MIB-1 SIs of the 57 cases ranged from 0.06-6.8% (median, 0.80%). There were 26 GR0, 20 GR1, and 11 GR2 edema cases. The MIB-1 SI rose in order of increasing edema severity. There was a statistically significant correlation between the MIB-1 SI and the extent of brain edema (P<0.0001), and also between the tumor size and the extent of brain edema (P=0.001). Meningothelial and atypical/anaplastic meningiomas were associated with peritumoral brain edema more often than any other subtype (P<0.005). CONCLUSIONS: Growth fractions, as determined by MIB-1 immunostaining, rise with increasing severity of peritumoral brain edema, indicating a close relationship between tumor aggressiveness and edema development.     

The importance of pial blood supply to the development of peritumoral brain edema in meningiomas

In a retrospective analysis, the authors studied the pial and dural blood supplies in 74 intracranial meningiomas and quantified their associated peritumoral brain edema (PTBE). The extent and localization of pial blush in relation to the total tumor volume were determined angiographically. The amount of edema and tumor size were calculated using computerized tomography. The edema-tumor volume ratio was defined as Edema Index (EI). There were 49 meningiomas with PTBE; of those tumors, 46 were supplied by pial vessels, and three were supplied exclusively by dural vessels. Tumors without PTBE showed no pial blush. The mean EI in meningiomas with pial blush was significantly larger (EI = 3) than in meningiomas without pial supply (EI = 1.1; p < 0.0001). Meningiomas with a smaller pial supply than dural supply had a significantly smaller mean EI than tumors with a pial supply equal to or greater than the dural supply (EI = 2.9 vs. EI = 3.7; p < 0.015). In 69.9% of cases with pial blood supply, major portions of the edema were located adjacent to the tumor region supplied by pial vessels. Edema index differences among tumors of different subgroups, as defined by size or histology, were significantly related to the pial supply in each subset. Thus, pial blood supply may be associated with the development of PTBE in meningiomas.     

Somatostatin receptor imaging in intracranial tumours

The somatostatin analogue [111In-DTPA-d-Phe1]-octreotide (111In-octreotide) allows scintigraphic visualization of somatostatin receptor-expressing tissue. While it is well known that a large variety of tissues express somatostatin receptors and 111In-octreotide scintigraphy has a clearly defined role in various neuroendocrine diseases, the clinical value of 111In-octreotide scintigraphy in brain tumours is still under clinical investigation. In 124 patients with 141 brain lesions (63 meningiomas, 24 pituitary adenomas, 10 gliomas WHO class I and II, 12 gliomas WHO class III and IV, 11 neurinomas and 2 neurofibromas, 7 metastases and 12 other varieties: three non-Hodgkin B-cell lymphomas, two epidermoids, one abscess, one angioleiomyoma, one chordoma, one haemangiopericytoma, one osteosarcoma, one plasmacytoma and one pseudocyst), 111In-octreotide scintigraphy was performed 4-6 and 24 h after i.v. injection of 110-220 MBq 111In-octreotide. Planar images of the head in four views with a 128x128 matrix and single-photon emission tomographic images (64x64 matrix) were acquired, and lesions were graded according to qualitative tracer uptake. Fifty-nine of the 63 meningiomas showed moderate to intense tracer uptake. Nine of 24 pituitary adenomas were visible; the remaining 15 did not show any tracer uptake. None of the class I and II gliomas with an intact blood-brain barrier were detected whereas 11/12 class III and IV gliomas showed 111In-octreotide uptake. None of the neurinomas or neurofibromas were positive. Five of seven metastases were classified as positive, as were the osteosarcoma, two of three non-Hodgkin B-cell lymphomas, one abscess, one angioleiomyoma, one chordoma and one haemangiopericytoma. The other varieties (one non-Hodgkin B-cell lymphoma, two epidermoids, one plasmacytoma and one pseudocyst) did not show 111In-octreotide uptake. The results demonstrate that a large variety of intracranial lesions express somatostatin receptors and therefore can be visualized by [111In-DTPA-d-Phe1]-octreotide scintigraphy. This technique can be valuable in the differentiation between meningiomas and pituitary adenomas, based on qualitative tracer uptake. [111In-DTPA-d-Phe1]-octreotide scintigraphy allows differentiation between meningiomas and neurinomas or neurofibromas and therefore provides complementary information to computed tomography or magnetic resonance imaging. Furthermore, this technique allows differentiation between scar tissue and recurrent meningiomas postoperatively and can help in non-invasive tumour differentiation of multiple intracranial lesions, which can be of value in defining the most adequate therapeutic strategy.     

Multiple neoplasms of the salivary gland and the lung

Intracranial adenoid cystic carcinoma is uncommon. We report two unusual cases of intracranial adenoid cystic carcinoma. The first patient presented with a steroid-responsive optic neuropathy from an orbital mass that simulated orbital pseudotumor, and subsequently developed intracranial involvement, presumably by contiguous perineural spread. The second patient presented with proptosis of the left eye, right facial weakness and numbness, and an intracranial mass, presumably from hematogenous metastatic spread.     

Stereotactic radiosurgery for tentorial meningiomas

Radical microsurgical resection is the procedure of choice for tentorial meningiomas. Despite advances in microsurgery, tentorial meningiomas continue to challenge surgeons and patients. To evaluate the response of tentorial meningiomas, we evaluated 41 patients who had Gamma knife stereotactic radiosurgery during a 9 year period. Patient age varied from 32 to 79 years. Headache, trigeminal neuralgia, or facial paraesthesia were the most common presenting symptoms. Sensory deficits in the distribution of the trigeminal nerve were the most common finding. Eighteen patients (44%) had undergone between 1 and 5 (mean, 1.9) resections prior to radiosurgery; 23 had tumors diagnosed by neuroimaging. The average tumor diameter in this series was 20 mm. The maximum tumor dose varied from 24 to 40 Gy (mean, 30.5 Gy), and the tumor margin dose varied from 12 to 20 Gy (mean, 15.3 Gy). During the average follow-up interval of 3 years (range, 1-8 years), 19 patients had clinical improvement, 20 remained stable, and 2 patients deteriorated. Follow-up imaging showed a reduction in tumor size in 18 patients, no further tumor growth in 22, and an increase in tumor size in one (overall tumor control rate of 98%). Stereotactic radiosurgery using the Gamma Knife was a safe and effective primary or adjuvant treatment for patients with tentorial meningiomas.     

Evaluation of intracranial cysts by intraoperative MR

Eleven patients with intracranial cystic collections were evaluated in the open-bore intraoperative MR system. In each case, the cystic collection or the surrounding cerebrospinal fluid (CSF) space was injected with .02 to .5 cc of .5 mol/l gadopentetate dimeglumine. Serial imaging was performed using T1-weighted imaging. In seven patients, free communication was demonstrated between the cystic collection and the surrounding CSF spaces. In four cases, the cyst did not communicate with the CSF; two of these were drained in the intraoperative MR system with reduction in symptoms. One patient developed an aseptic meningitis 10 days after the study, which was successfully treated with steroids; no other complications were noted. We conclude that the communication of intracranial cystic collections with the cisterns and ventricles can be safely and effectively elucidated with gadolinium injection in the intraoperative MR system.