Extracranial meningioma metastases (EMM) occur in 0.1% of intracranial meningioma patients and are more commonly seen in those with atypical and anaplastic histologies. While the lungs and pleura are the most common site of EMM, intraspinal and vertebral EMM also occur and are not well described in the literature. Although the presence of EMM can worsen prognosis, no standard of care has been established for EMM management. All patients treated for recurrent atypical/anaplastic meningiomas between January 1985 and July 2014 at Memorial Sloan Kettering Cancer Center were screened for intraspinal and vertebral EMM. Of these patients, 2 were identified as having recurrent meningioma complicated by vertebral or intraspinal EMM. A review of the literature was also conducted. The PubMed database was screened for intraspinal and vertebral EMM cases reported in the literature from 1985 to 2015. Nineteen articles were identified from the literature and included 24 individual cases with a total of 34 vertebral or intraspinal EMM. Forty-two percent (10/24) of patients with vertebral or intraspinal EMM had WHO Grade I tumors. Furthermore, 25% (6/24) of vertebral and intraspinal EMM occurred after the primary tumor but prior to any recurrence. This paper highlights that vertebral and intraspinal EMM can occur in patients with WHO Grade I meningiomas and can occur before tumor recurrence. This challenges the notion that EMM are seen primarily in high-grade atypical and anaplastic meningiomas 1).
Meningioma patients are characterised by long term deficits in neurocognitive functioning that can partly be attributed to the use of antiepileptic drugs and tumour location but not to the use of radiotherapy 2).
Current recommendations stress the need for cognitive parameters to be integrated in the evaluation of outcomes for intracranial meningioma surgery.
Patients with skull base (anterior and middle fossa) and convexity (anterior and posterior) meningiomas (n = 54) underwent neuropsychological examination prior to and 1 year after surgery. A control group (n = 52) of healthy volunteers matched for age, sex, and education underwent the same examination. Assessments included executive funtions, memory, and motor functions with standardized testing. Patients with convexity meningiomas were clinically assessed for parietal association cortex functions.
All patients performed significantly worse (p < 0.05) in most neurocognitive domains than controls. The skull base group showed more disturbances in memory than the convexity group (p < 0.05). The anterior convexity group showed more deficits in executive function than the posterior convexity group, which presented with parietal association cortex deficits. Verbal deficits were more pronounced in the left hemisphere than in the right hemisphere. Patients with a large tumor (> 4 cm) had more severe neurocognitive deficits than those with a small tumor (< 4 cm). Postoperatively, patients showed no deterioration in neurocognitive function. Instead, significant improvement (p < 0.05) was observed in some executive, motor, and parietal association cortex functions.
According to the authors' findings, intracranial meningiomas may cause neurocognitive deficits in patients. Surgery does not cause a deterioration in cognitive function; instead, it may lead to improvements in some functions. Permanent neuropsychological postoperative deficits should be interpreted as tumor-induced rather than due to surgery 3).
The ability of preoperative MRI-sequences to predict the consistency of intracranial meningiomas has not yet been clearly defined.
Romani et al., prospectively studied 110 meningioma patients operated on in a single center from March 1st to the 25th of May 2012. Demographic data, location and size of the tumor, peritumoral edema, T1 weighted image, T2WI, proton density weighted (PDWI), fluid-attenuated inversion recover (FLAIR) sequences, and arterial spin labeling (ASL) perfusion were studied and compared with the gray matter signal to predict meningioma consistency. Diffusion tensor imaging (DTI) with fractional anisotropy (FA) and mean diffusivity (MD) maps were included in the preoperative MRI. Meningioma consistency was evaluated by the operating surgeon who was unaware of the neuroradiological findings.
In univariate analysis, meningioma size (diameter > 2 cm) and supratentorial or sphenoidal wing location were more frequently associated with hard-consistency meningiomas (p < 0.05). In addition, isointense signal on MD maps (p = 0.009), hyperintense signal on FA maps, and FA value > 0.3 (p = 0.00001) were associated with hard-consistency tumors. Age and sex, T1WI, T2WI, PDWI, FLAIR, or ASL perfusion sequences and peritumoral edema were not significantly associated with meningioma consistency. In logistic regression analysis, the most accurate model (AUC: 0.9459) for predicting a hard-consistency meningioma shows that an isointense signal in MD-maps, a hyperintense signal in FA-maps, and an FA value of more than 0.3 have a significant predictive value.
FA value and MD and FA maps are useful for prediction of meningioma consistency and, therefore, may be considered in the preoperative routine MRI examination of all patients with intracranial meningiomas 4).
Although the optimal management of meningiomas would provide complete elimination of the lesion, this cannot always be accomplished safely through resection. Therefore, other therapeutic modalities, such as stereotactic radiosurgery (as primary or adjunctive therapy), have emerged 5).
Main goal of meningioma surgery is to obtain the complete tumor resection in order to reduce the recurrence rate but preserving or improving the patient's neurological functions 6)
In many cases this is a difficult achievement, because of the risk of damages to arteries, sinuses, cranial nerves or other neighbors relevant structures. Surgical morbidity and mortality are mainly related to tumor location and volume 7).
Stereotactic radiosurgery (SRS) has become a common treatment modality for intracranial meningiomas. Skull base meningiomas greater than 8 cm(3) in volume have been found to have worse outcomes following SRS. When symptomatic, patients with these tumors are often initially treated with resection. For tumors located in close proximity to eloquent structures or in patients unwilling or unable to undergo a resection, SRS may be an acceptable therapeutic approach.
Starke et al. review the SRS outcomes of skull base meningiomas greater than 8 cm(3) in volume, which corresponds to a lesion with an approximate diameter of 2.5 cm. The authors reviewed the data in a prospectively compiled database documenting the outcomes of 469 patients with skull base meningiomas treated with single-session Gamma Knife radiosurgery (GKRS). Seventy-five patients had tumors greater than 8 cm(3) in volume, which was defined as a large tumor. All patients had a minimum follow-up of 6 months, but patients were included if they had a complication at any time point. Thirty patients were treated with upfront GKRS, and 45 were treated following microsurgery. Patient and tumor characteristics were assessed to determine predictors of new or worsening neurological function and tumor progression following GKRS.
After a mean follow-up of 6.5 years (range 0.5-21 years), the tumor volume was unchanged in 37 patients (49%), decreased in 26 patients (35%), and increased in 12 patients (16%). Actuarial rates of progression-free survival at 3, 5, and 10 years were 90.3%, 88.6%, and 77.2%, respectively. Four patients had new or worsened edema following GKRS, but preexisting edema decreased in 3 patients. In Cox multivariable analysis, covariates associated with tumor progression were 1) presentation with any cranial nerve (CN) deficit from III to VI (hazard ratio [HR] 3.78, 95% CI 1.91-7.45; p < 0.001), history of radiotherapy (HR 12.06, 95% CI 2.04-71.27; p = 0.006), and tumor volume greater than 14 cm(3) (HR 6.86, 95% CI 0.88-53.36; p = 0.066). In those patients with detailed clinical follow-up (n = 64), neurological function was unchanged in 37 patients (58%), improved in 16 patients (25%), and deteriorated in 11 patients (17%). In multivariate analysis, the factors predictive of new or worsening neurological function were history of surgery (OR 3.00, 95% CI 1.13-7.95; p = 0.027), presentation with any CN deficit from III to VI (OR 3.94, 95% CI 1.49-10.24; p = 0.007), and decreasing maximal dose (OR 0.76, 95% CI 0.63-0.93; p = 0.007). Tumor progression was present in 64% of patients with new or worsening neurological decline.
Stereotactic radiosurgery affords a reasonable rate of tumor control for large skull base meningiomas and does so with a low incidence of neurological deficits. Those with a tumor less than 14 cm(3) in volume and without presenting CN deficit from III to VI were more likely to have effective tumor control 8).
Conventional open surgery of large meningiomas has proven to be challenging even in experienced hands. Intense retraction and dissection around neurovascular structures increase morbidity and mortality.
Large size of tumors, difficulties in resection and preexisting conditions are primary causes of a high rate of operative morbidity in elderly patients receiving meningioma removal 9).
Removal of an intracranial meningioma carries a higher risk of post-operative hemorrhage compared to surgery for other intracranial neoplasms.
21 patients (7.1 %) of 296 patients developed a post-operative intracranial hematoma requiring surgical evacuation. Age was significantly higher in the hematoma group 62.4 +/- 14.0 years compared to patients without post-operative hematoma 56.1 +/- 12.0 (p < 0.05; t-test). Patients older than 70 years had a six-fold increased risk to develop a post-operative hematoma (Chi2 test, 95% CI 1.949-13.224). Patients with post-operative hemorrhage had significant lower post-operative prothrombin time, fibrinogen and platelets immediately after surgery and lower platelets at day 1. None of the other parameters, including pre-operative routine coagulation values, differed significantly between patients with and without post-operative hemorrhage. Three patients with post-operative hematoma showed platelet dysfunction and three patients showed decreased FXIII activity. Of those patients with post-operative hemorrhage at three months follow up three patients (13%) succumbed from reasons not directly related to hemorrhage, one patient remained GOS 2 (4.3%), four patients (17.4%) were GOS 3 and 15 (65.4%) patients had favorable outcome (GOS 4 [one patient] and GOS5 [14 patients]). Meningioma surgery carries a higher risk for post-operative hematoma in the elderly. Thrombocytopenia and other hemostatic disorders were frequently associated with post-operative hemorrhage after meningioma surgery, while no surgical factors could be defined. Extending coagulation tests and specific replacement therapy may prevent hematoma formation and improve the patients outcome 10).
Five hundred and five operations for intracranial meningiomas were complicated by 18 postoperative hematomas (POH)–3.56%. The POH were more frequently encountered in older patients and/or patients with atherosclerosis, arterial hypertension and diabetes. Longer lasting operations especially cases with intraoperative fall of blood pressure were more often complicated by POH. The POH were more frequently observed following total excision than partial removal and after convexity meningioma operations than other locations. The outcome of the operations complicated by POH was related to the time of their clinical manifestation and removal 11).
Fourteen factors possibly correlated with early postoperative seizures in a cohort of 209 elderly patients who had undergone meningioma resection, as analyzed by multifactorial stepwise logistic regression. Phenobarbital sodium (0.1 g, intramuscularly) was administered to all 209 patients 30 min prior to undergoing surgery. All the patients had no previous history of seizures. The correlation of the 14 clinical factors (gender, tumor site, dyskinesia, peritumoral brain edema (PTBE), tumor diameter, pre- and postoperative prophylaxes, surgery time, tumor adhesion, circumscription, blood supply, intraoperative transfusion, original site of the tumor and dysphasia) was assessed in association with the risk for post-operative seizures. Tumor diameter, postoperative prophylactic antiepileptic drug (PPAD) administration, PTBE and tumor site were entered as risk factors into a mathematical regression model. The odds ratio (OR) of the tumor diameter was >1, and PPAD administration showed an OR >1, relative to a non-prophylactic group. A logistic regression equation was obtained and the sensitivity, specificity and misdiagnosis rates were 91.4, 74.3 and 25.7%, respectively. Tumor diameter, PPAD administration, PTBE and tumor site were closely correlated with early postoperative seizures; PTBE and PPAD administration were risk and protective factors, respectively 12).
Meningiomas are associated with the highest postoperative rate of venous thromboembolic events (VTE) among all intracranial tumors.
Intraoperative leg-elevation, intermittent pneumatic compression (IPC), early heparin administration and low-molecular-weight heparin (LMWH) 13).
All histologically proven intracranial meningiomas that underwent resection in a single centre between April 2009 and April 2014 were reviewed and classified according to the 2016 edition of the Classification of the Tumours of the CNS. Only patients who had two pre-operative scans that were at least 3 months apart were included in the study. Two authors performed the volumetric measurements using the Slicer 3D software independently and the inter-rater reliability was assessed. Multiple regression analyses of factors affecting the VGR and VDE of meningiomas were performed using the R statistical software with p < 0.05 considered to be statistically significant.
Of 548 patients who underwent resection of their meningiomas, 66 met the inclusion criteria. Sixteen cases met the exclusion criteria (NF2, spinal location, previous surgical or radiation treatment, significant intra-osseous component and poor quality imaging). Forty-two grade I and 8 grade II meningiomas were included in the analysis. The VGR was significantly higher for grade II meningiomas. Using receiver-operator characteristic (ROC) curve analysis, the optimal threshold that distinguishes between grade I and II meningiomas is 3 cm3/year. Higher histological grade, high initial tumour volume, MRI T2-signal hyperintensity and presence of oedema were found to be significant predictors of higher VGR.
Reliable tools now exist to evaluate and monitor volumetric growth of meningiomas. Grade II meningiomas have significantly higher volumetric growth rate (VGR) compared with grade I meningiomas and growth of more than 3 cm3/year is strongly suggestive of a higher grade meningioma. A larger, multi-centre prospective study to investigate the applicability of velocity of growth to predict the outcome of patients with meningioma is warranted 14).
Park et al. present a retrospective case series of 5 females at our institutions (age ranged 21-72 years, mean 54.6 years) diagnosed with LD of an intracranial meningioma after surgery between 1998 and 2013. A database search revealed 45 cases with LD of meningioma in the English literature. Characteristic features were analyzed and compared.
The incidence rate at our institutions of LD of meningioma was 0.9% (5/534). World Health Organization (WHO) grade was distributed as follows: I : 2, II : 2, and III : 1. Time to LD ranged from 2.5 months to 6.9 years; the patient with WHO grade III had the shortest interval to LD. The patient with an intraventricular meningioma (WHO grade II) had the second shortest interval to LD (1.7 years), and simultaneously revealed both LD and extraneuronal metastases. Four of 5 patients showed a disease progression, with the survival ranging from 1 month to 3.8 years after LD. Based on the literature, the initial tumor was an intraventricular meningioma in 9 patients, and their time to LD was shorter on average (mean 1.9 years). Histologically, 26 of 45 (58%) were initially diagnosed with a WHO grade II or III meningioma, and 6 of 19 patients (32%) with WHO grade I revealed malignant transformation.
This study shows that intraventricular location and histologically aggressive features seem to increase the chance of LD of meningioma 15).
A 42-year-old man presented with occasional headache. Neurological examination was negative. CT scans showed a mass lesion located in temporal region with homogeneous hyperdensity and foci calcification. The patients MRI studies demonstrated the lesion was hypointense on T1-weighted and T2-weighted MR images. After administration of Gd-DTPA, the lesion revealed neither enhancement nor dural tail sign. After gross total excision of the lesion was accomplished, histopathological examination confirmed the diagnosis of hyalinedegeneration-rich fibrous meningioma, which represented a distinctive pathologic manifestation.
This report illustrates common meningiomas possess the rare occurrence of uncommon neuroimaging characteristics and pathological features. According to radiological and pathological features, the causes of rare imaging characteristics were discussed 16).