An audit of immunohistochemical marker patterns in meningioma

Risk of intracranial meningioma in patients with acromegaly: a systematic review

Acromegaly is a rare endocrine disorder caused by hypersecretion of growth hormone (GH) from a pituitary adenoma. Elevated GH levels stimulate excess production of insulin-like growth factor 1 (IGF-1) which leads to the insidious onset of clinical manifestations. The most common primary central nervous system (CNS) tumors, meningiomas originate from the arachnoid layer of the meninges and are typically benign and slow-growing. Meningiomas are over twice as common in women as in men, with age-adjusted incidence (per 100,000 individuals) of 10.66 and 4.75, respectively. Several reports describe co-occurrence of meningiomas and acromegaly. We aimed to determine whether patients with acromegaly are at elevated risk for meningioma. Investigation of the literature showed that co-occurrence of a pituitary adenoma and a meningioma is a rare phenomenon, and the majority of cases involve GH-secreting adenomas. To the best of our knowledge, a systematic review examining the association between meningiomas and elevated GH levels (due to GH-secreting adenomas in acromegaly or exposure to exogenous GH) has never been conducted. The nature of the observed coexistence between acromegaly and meningioma -whether it reflects causation or mere co-association -is unclear, as is the pathophysiologic etiology.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022376998.

Use of progestogens and the risk of intracranial meningioma: national case-control study

OBJECTIVE

To assess the risk of intracranial meningioma associated with the use of selected progestogens.

DESIGN

National case-control study.

SETTING

French National Health Data System (ie, Système National des Données de Santé).

PARTICIPANTS

Of 108 366 women overall, 18 061 women living in France who had intracranial surgery for meningioma between 1 January 2009 and 31 December 2018 (restricted inclusion periods for intrauterine systems) were deemed to be in the case group. Each case was matched to five controls for year of birth and area of residence (90 305 controls).

MAIN OUTCOME MEASURES

Selected progestogens were used: progesterone, hydroxyprogesterone, dydrogesterone, medrogestone, medroxyprogesterone acetate, promegestone, dienogest, and intrauterine levonorgestrel. For each progestogen, use was defined by at least one dispensation within the year before the index date (within three years for 13.5 mg levonorgestrel intrauterine systems and five years for 52 mg). Conditional logistic regression was used to calculate odds ratio for each progestogen meningioma association.

RESULTS

Mean age was 57.6 years (standard deviation 12.8). Analyses showed excess risk of meningioma with use of medrogestone (42 exposed cases/18 061 cases (0.2%) v 79 exposed controls/90 305 controls (0.1%), odds ratio 3.49 (95% confidence interval 2.38 to 5.10)), medroxyprogesterone acetate (injectable, 9/18 061 (0.05%) v 11/90 305 (0.01%), 5.55 (2.27 to 13.56)), and promegestone (83/18 061 (0.5%) v 225/90 305 (0.2 %), 2.39 (1.85 to 3.09)). This excess risk was driven by prolonged use (≥one year). Results showed no excess risk of intracranial meningioma for progesterone, dydrogesterone, or levonorgestrel intrauterine systems. No conclusions could be drawn concerning dienogest or hydroxyprogesterone because of the small number of individuals who received these drugs. A highly increased risk of meningioma was observed for cyproterone acetate (891/18 061 (4.9%) v 256/90 305 (0.3%), odds ratio 19.21 (95% confidence interval 16.61 to 22.22)), nomegestrol acetate (925/18 061 (5.1%) v 1121/90 305 (1.2%), 4.93 (4.50 to 5.41)), and chlormadinone acetate (628/18 061 (3.5%) v 946/90 305 (1.0%), 3.87 (3.48 to 4.30)), which were used as positive controls for use.

CONCLUSIONS

Prolonged use of medrogestone, medroxyprogesterone acetate, and promegestone was found to increase the risk of intracranial meningioma. The increased risk associated with the use of injectable medroxyprogesterone acetate, a widely used contraceptive, and the safety of levonorgestrel intrauterine systems are important new findings.

Novel Advances in Treatment of Meningiomas: Prognostic and Therapeutic Implications

Meningiomas are the most frequent histotypes of tumors of the central nervous system. Their incidence is approximately 35% of all primary brain tumors. Although they have the status of benign lesions, meningiomas are often associated with a decreased quality of life due to focal neurological deficits that may be related. The optimal treatment is total resection. Histological grading is the most important prognostic factor. Recently, molecular alterations have been identified that are specifically related to particular phenotypes and, probably, are also responsible for grading, site, and prognostic trend. Meningiomas recur in 10-25% of cases. In these cases, and in patients with atypical or anaplastic meningiomas, the methods of approach are relatively insufficient. To date, data on the molecular biology, genetics, and epigenetics of meningiomas are insufficient. To achieve an optimal treatment strategy, it is necessary to identify the mechanisms that regulate tumor formation and progression. Combination therapies affecting multiple molecular targets are currently opening up and have significant promise as adjuvant therapeutic options. We review the most recent literature to identify studies investigating recent therapeutic treatments recently used for meningiomas.

Inhibition of the epigenetically activated miR-483-5p/IGF-2 pathway results in rapid loss of meningioma tumor cell viability

PURPOSE

Meningioma is the most common primary central nervous system tumor often causing serious complications, and presently no medical treatment is available. The goal of this study was to discover miRNAs dysregulated in meningioma, and explore miRNA-associated pathways amenable for therapeutic interventions.

METHODS

Small RNA sequencing was performed on meningioma tumor samples to study grade-dependent changes in microRNA expression. Gene expression was analyzed by chromatin marks, qRT-PCR and western blot. miRNA modulation, anti-IGF-2 neutralizing antibodies, and inhibitors against IGF1R were evaluated in a tumor-derived primary cultures of meningioma cells.

RESULTS

Meningioma tumor samples showed high, grade-dependent expression of miR-483-5p, associated with high mRNA and protein expression of its host gene IGF-2. Inhibition of miR-483-5p reduced the growth of cultured meningioma cells, whereas a miR-483 mimic increased cell proliferation. Similarly, inhibition of this pathway with anti-IGF-2 neutralizing antibodies reduced meningioma cell proliferation. Small molecule tyrosine kinase inhibitor blockade of the IGF-2 receptor (IGF1R) resulted in rapid loss of viability of cultured meningioma tumor-derived cells, suggesting that autocrine IGF-2 feedback is obligatory for meningioma tumor cell survival and growth. The observed IGF1R-inhibitory IC50 for GSK1838705A and ceritinib in cell-based assays along with the available pharmacokinetics data predicted that effective drug concentration could be achieved in vivo as a new medical treatment of meningioma.

CONCLUSION

Meningioma cell growth is critically dependent on autocrine miR-483/IGF-2 stimulation and the IGF-2 pathway provides a feasible meningioma treatment target.

Hormone Receptor Expression in Meningiomas: A Systematic Review

Meningiomas are, in most cases, low grade intracranial tumors. However, relapses are frequent. To date, only a few prognostic markers are described in the literature. Several studies have discussed the expression of progesterone, estrogen, androgen, and somatostatin receptors. The utility of analyzing these expressions for prognostic, theragnostic, and therapeutic purposes remains unclear. The aim of this study was to report the expression of these receptors, based on immunohistochemistry. Cochrane Collaboration guidelines and PRISMA statements were followed. We did an online search in PubMed using the MeSH database. References were selected if the investigations occurred from 1990 to 2022. 61 references were included (34 descriptive observational studies, 26 analytical observational studies, and one case report). In this review, we describe the expression of these receptors in function of age, sex, hormonal context, localization, histological subtype, grade, and recurrence.

Lateral ventricle meningiomas in children: clinicopathological and neuroradiological features

PURPOSE

Lateral ventricle meningiomas (LVM) in children are very rare. The current research is mostly limited to adults, and there are very few related studies on children. The purpose of this study was to analyze the clinicopathological and imaging features of lateral ventricle meningiomas in children.

METHODS

A retrospective analysis of five children with pathologically confirmed lateral ventricle meningioma was performed, and we collected clinical data, including clinicopathological data, treatment prognosis data, and imaging features (including tumor location, signal intensity, enhancement degree, intratumoral cyst, calcification, peritumoral edema, and associated hydrocephalus).

RESULTS

Among the 5 patients with LVM, 4 were male and 1 was female with an average age of 7.6 years (range 2 to 12 years). All CT scans showed slight hyperintensity or isodensity, and only 1 patient had calcification. Two patients demonstrated cyst changes. Four patients had varying degrees of peritumoral edema. The average tumor volume was 164.1 cm³ (1.4-314.9 cm³). All 5 patients with LVM were iso- or hypointense on T1WI. The T2WI signals had no obvious features. Four patients had a high signal on DWI (80%). The contrast-enhanced signals were mostly homogeneously strong (80%). MRI showed hydrocephalus in 3 patients. All patients underwent gross total resection, and they were followed up regularly after the operation. The average follow-up time was 47.4 months. No recurrence was found in any of the children. All patients were pathologically confirmed to have meningiomas, and WHO grades were all grade I.

CONCLUSION

Lateral ventricle meningiomas in children are very rare, and the imaging manifestations of the tumor have certain characteristics, but the clinical diagnosis is still difficult, and the diagnosis still requires pathological analysis.

Molecular diagnosis and treatment of meningiomas: an expert consensus (2022)

ABSTRACT

Meningiomas are the most common primary intracranial neoplasm with diverse pathological types and complicated clinical manifestations. The fifth edition of the WHO Classification of Tumors of the Central Nervous System (WHO CNS5), published in 2021, introduces major changes that advance the role of molecular diagnostics in meningiomas. To follow the revision of WHO CNS5, this expert consensus statement was formed jointly by the Group of Neuro-Oncology, Society of Neurosurgery, Chinese Medical Association together with neuropathologists and evidence-based experts. The consensus provides reference points to integrate key biomarkers into stratification and clinical decision making for meningioma patients.

REGISTRATION

Practice guideline REgistration for transPAREncy (PREPARE), IPGRP-2022CN234.

The evolution and ecology of benign tumors

Tumors are usually classified into two main categories - benign or malignant, with much more attention being devoted to the second category given that they are usually associated with more severe health issues (i.e., metastatic cancers). Here, we argue that the mechanistic distinction between benign and malignant tumors has narrowed our understanding of neoplastic processes. This review provides the first comprehensive discussion of benign tumors in the context of their evolution and ecology as well as interactions with their hosts. We compare the genetic and epigenetic profiles, cellular activities, and the involvement of viruses in benign and malignant tumors. We also address the impact of intra-tumoral cell composition and its relationship with the tumoral microenvironment. Lastly, we explore the differences in the distribution of benign and malignant neoplasia across the tree of life and provide examples on how benign tumors can also affect individual fitness and consequently the evolutionary trajectories of populations and species. Overall, our goal is to bring attention to the non-cancerous manifestations of tumors, at different scales, and to stimulate research on the evolutionary ecology of host-tumor interactions on a broader scale. Ultimately, we suggest that a better appreciation of the differences and similarities between benign and malignant tumors is fundamental to our understanding of malignancy both at mechanistic and evolutionary levels.

The risk of developing a meningioma during and after pregnancy

Pregnancy has been associated with diagnosis or growth of meningiomas in several case reports, which has led to the hypothesis that pregnancy may be a risk factor for meningiomas. The aim of this study was to test this hypothesis in a large population-based cohort study. Women born in Sweden 1958–2000 (N = 2,204,126) were identified and matched with the Medical Birth Register and the Cancer Register. The expected number of meningioma cases and risk ratios were calculated for parous and nulliparous women and compared to the observed number of cases. Compared to parous women, meningiomas were more common among nulliparous (SIR = 1.73; 95% CI 1.52–1.95). The number of meningioma cases detected during pregnancy was lower than the expected (SIR = 0.40; 95% CI 0.20–0.72). Moreover, no increased risk was found in the first-year post-partum (SIR = 1.04; 95% CI 0.74–1.41). Contrary to our hypothesis, there was no increased risk for diagnosing a meningioma during pregnancy or 1-year post-partum. A lower detection rate during pregnancy, may reflect under-utilization of diagnostic procedures, but the actual number of meningiomas was homogenously lower among parous than nulliparous women throughout the study period, indicating that pregnancy is not a risk factor for meningioma.

Increased Incidence of Intracranial Meningiomas in Patients With Acromegaly

BACKGROUND

An increased incidence of various neoplasms has been described in patients with acromegaly, and there is evidence to suggest that growth factors are risk factors for the development of meningiomas.

OBJECTIVE

To study if patients with acromegaly are more at risk for developing intracranial meningiomas.

METHODS

We conducted an observational study on 221 consecutive acromegalic patients recruited between January 1, 2000 and December 31, 2015, and 357 consecutive patients with a nonsomatotropic pituitary adenoma recruited between March 1, 2015 and December 31, 2016, in our institution. Patients underwent a gadolinium-enhanced 3D T1 brain magnetic resonance imaging to look for meningiomas. The proportion of meningiomas was compared between the 2 groups, and the standardized incidence ratio (SIR) was computed from the incidence rates of meningiomas observed in the population of acromegalic patients and compared to that of the general population given by the local registry of central nervous system tumors.

RESULTS

Patients with acromegaly had a significant risk for developing intracranial meningiomas as compared to patients without acromegaly (7.7% vs 2.2%, P = .005, OR = 3.45 [1.46; 8.15]). There was a significant increased incidence of intracranial meningiomas in patients with acromegaly (SIR = 126 [25; 367]) as compared to the general population.

CONCLUSION

Our study suggests strongly that patients with acromegaly are more at risk for developing intracranial meningiomas.

A Grade I Intracranial Meningioma with Metastasis to Multiple Vertebral Bodies: A Case Report and Literature Review

World Health Organization (WHO) grade I meningiomas are slow-growing and typically benign brain tumors that can often be easily removed by surgery and rarely become malignant. We report the case of a WHO grade I meningioma in a 67-year-old man with multiple extracranial metastases.

The relationship between vascular endothelial growth factor and histological grade in intracranial meningioma

Background

Meningioma is the most common benign intracranial neoplasm, accounting for 30% of all primary brain tumors. In 90% of cases, meningiomas are benign. Several aspects of molecular biology, including potential biomarkers, have been studied in attempts to better understand the natural history of meningiomas. Vascular endothelial growth factor (VEGF) is a biomarker responsible for inducing physiological and pathological angiogenesis. VEGF expression has been investigated as a potential predictor of several tumor aspects, including growth rate, recurrence rate, brain tissue invasion, peritumoral edema and surgical prognosis, and also as a marker of histological grade. However, there is no consensus in the literature with respect to the association between this biological factor and meningioma. We digitally analyzed immunohistochemical images using ImageJ software with the aim of correlating VEGF expression with tumor histology.

Methods

Tissue samples from patients presenting with meningioma who had undergone surgical removal between 2007 and 2016 at the Hospital de Clínicas de Porto Alegre (HCPA), in Southern Brazil, were analyzed to identify possible immunohistochemical associations between VEGF and histological grade and subtype.

Results

Seventy-six patients were included; 82% were female, mean age was 59.9 years (range: 18-91). No statistically significant associations were found between VEGF expression and histological grade or subtype (P = 0.310).

Conclusion

Our findings suggest that VEGF is frequently present in meningiomas regardless of histological grade and should not be used as a marker of severity or histological grade.

The Ki-67 Proliferation Index as a Marker of Time to Recurrence in Intracranial Meningioma

BACKGROUND

There are examples of incongruence between the WHO grade and clinical course in meningioma patients. This incongruence between WHO grade and recurrence has led to search for other prognostic histological markers.

OBJECTIVE

To study the correlation between the Ki-67 proliferative index (PI), risk of recurrence, and recurrence rates in meningioma patients.

METHODS

We prospectively collected pathological diagnosis of de novo consecutive meningiomas. In total, we followed 159 patients with clinical controls until recurrence, death, or emigration. We estimated the correlation between risk of recurrence and Ki-67 PI when adjusted for age at diagnosis, sex, WHO grade, extent of surgical resection, and tumor location. We estimated the cumulative incidence of recurrence when considering death without recurrence a competing risk. We report recurrence rates per 100 person-years.

RESULTS

A 1%-point increase of Ki-67 PI yielded a hazard ratio of 1.12 (95% CI: 1.01-1.24) in a multivariate analysis. The cumulative incidence of recurrence was 3% for Ki-67 0% to 4% vs 19% for Ki-67 > 4% meningiomas after 1 yr, but 24% vs 35%, respectively, after 10 yr. There was no significant difference in mean Ki-67 PI between nonrecurrent and recurrent meningioma in a 2-sample t-test (P = .08). The strongest relationship was detected between Ki-67 PI and time to recurrence: Ki-67 < 4% meningiomas recurred after median 4.8 yr, compared to 0.60 to 0.75 yr for patients with higher Ki-67 PI.

CONCLUSION

Ki-67 PI was a marker for time to recurrence rather than a predictor of recurrence. Ki-67 PI may be utilized for patient tailored follow-up.

New Insights into Expression of Hormonal Receptors by Meningiomas

OBJECTIVE

Meningiomas have a female predilection, which is even stronger for spinal than for intracranial meningiomas. The relationship between meningiomas and endogenous or exogenous sex hormones such as cyproterone acetate (CPA) is well documented, yet their underlying mechanism remains unknown. Clarification of the expression profile of hormonal receptors by meningiomas would help us to better understand their hormonal susceptibility.

METHODS

We used tissue microarray and immunohistochemistry to determine the receptor status of the 3 main sex hormones: androgen (AR), estrogen, and progesterone (PR) in 30 intracranial meningiomas, 30 spinal meningiomas, and 30 meningiomas developed on CPA.

RESULTS

AR status was positive in 73% of meningiomas in the intracranial group, 87% of meningiomas in the CPA group, and in all meningiomas in the spinal group. Estrogen status was positive in only 7% of meningiomas in the intracranial group and in only 3% of meningiomas in the CPA group but in 30% of meningiomas in the spinal group. PR status was positive in 90% of meningiomas in the intracranial group, in 97% of meningiomas in the CPA group, and in 87% of meningiomas in the spinal group. These specific hormonal receptor statuses based on immunoreactive score were reflected on staining intensities. Furthermore, AR and PR expression was correlated in each group.

CONCLUSIONS

Our study shows that intracranial meningiomas, spinal meningiomas, and meningiomas developed on CPA express specific hormonal receptor patterns. This result invites the scientific community to review the potential role of AR in the unbalanced sex ratio of meningiomas.

Surgical indications for pituitary tumors during pregnancy: a literature review

PURPOSE

Surgical indications for pituitary tumors during pregnancy are rare, and are derived from a balance between expected benefits, particularly for maternal benefits, and anesthetic/surgical risks.

METHODS

A literature review was performed to define the optimal surgical indications for pituitary adenomas (PA) and other pituitary tumors during pregnancy.

RESULTS

Main benefits are expected in case of critical visual impairment and/or life-threatening endocrine disturbances. Multidisciplinary patient management is systematically required although nonobstetric surgery presents a reasonable risk during pregnancy. The risks of congenital malformation during the first trimester and those of premature birth during the third trimester make the second trimester the optimal period for surgery. In prolactin-secreting, nonsecreting, GH- and TSH-secreting PAs, transsphenoidal surgery (TS) is recommended in cases involving severe visual impairment, characterized by severe visual field deficit, visual acuity impairment, and abnormal optical coherence tomography findings, and when no other medical alternatives are possible and/or sufficient. Uncontrolled and severe Cushing's disease (CD) during pregnancy increases both maternal and fetal morbimortality, thus justifying TS or sometimes dopamine agonist therapy as a safer alternative. Finally, metyrapone, ketoconazole, or bilateral adrenalectomy could be recommended in certain cases after the failure of medical therapies and/or TS. Surgery is also required for suprasellar meningiomas, craniopharyngiomas, and pituitary cysts in the case of severe visual deficit.

CONCLUSION

Surgical indications for pituitary tumors are rare during pregnancy; therefore, surgery should be avoided when possible. Further, the second trimester should be considered as the optimal surgical period. Severe visual disturbance and uncontrolled CD are the main surgical indications during pregnancy.

Companion animal models of neurological disease

Clinical translation of novel therapeutics that improve the survival and quality of life of patients with neurological disease remains a challenge, with many investigational drug and device candidates failing in advanced stage clinical trials. Naturally occurring inherited and acquired neurological diseases, such as epilepsy, inborn errors of metabolism, brain tumors, spinal cord injury, and stroke occur frequently in companion animals, and many of these share epidemiologic, pathophysiologic and clinical features with their human counterparts. As companion animals have a relatively abbreviated lifespan and genetic background, are immunocompetent, share their environment with human caregivers, and can be clinically managed using techniques and tools similar to those used in humans, they have tremendous potential for increasing the predictive value of preclinical drug and device studies. Here, we review comparative features of spontaneous neurological diseases in companion animals with an emphasis on neuroimaging methods and features, illustrate their historical use in translational studies, and discuss inherent limitations associated with each disease model. Integration of companion animals with naturally occurring disease into preclinical studies can complement and expand the knowledge gained from studies in other animal models, accelerate or improve the manner in which research is translated to the human clinic, and ultimately generate discoveries that will benefit the health of humans and animals.

A Practical Approach to the Differential Diagnosis of Intracranial Tumors: Gross, Histology, and Immunoprofile-based Algorithm

Intracranial tumors are a diverse group of conditions, both benign and malignant, primary and metastatic and always require detailed medical information, radiological reports and deep knowledge of the histological hallmarks and immunohistochemical profile of different types of tumors and tumor-like processes. Despite it clinically often being possible to differentiate between primary and metastatic tumors, based on the tumor location and age of the patient, histological variants and rare tumor entries should always be considered in the histological differential diagnosis. A thorough diagnostic algorithm based on the location of the tumor and its histological features, together with some common pitfalls in immunohistochemical profiling, based on the 2016 revised World Health Organization (WHO) classification of tumors of the central nervous system should be implemented in all cases. Such an algorithm is especially valuable in cases where only small tumor fragments are sent for morphological evaluation, such as in deep parenchyma tumors. In these instances where only small fragments of the tumor are present for histology, some key features, corresponding to the WHO grade, may easily be missed or underreported. Furthermore, the histological verification of the tumor entry is the first, often overlooked, step in defining the presence or absence of WHO grade-specific mutations.

Association of hormone replacement therapy with increased risk of meningioma in women: A hospital-based multicenter study with propensity score matching

AIM

There is no consensus regarding the association between hormone replacement therapy (HRT) and risk of meningioma so far. We conducted the first study among Chinese female patients to investigate the influence of HRT use on the risk of meningioma.

METHODS

We retrospectively collected records of diagnosis of meningioma for women aged 50 years and above during 2011-2016 and dispense of HRT prior to meningioma diagnosis in three tertiary hospitals in China. Meningioma cases were matched with controls at a ratio of 1:2 by using nearest neighbor propensity scores matching in order to balance the baseline characteristics between groups, which generated a total of 629 cases with 1258 controls.

RESULTS

We observed prior use of HRT associated with increased risk of meningioma (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.0-1.4) and the association was more prominent among women having multiple HRT dispenses and longer term exposure (OR, 1.3; 95% CI, 1.1-1.6), among those with combination therapy of estrogens and progestogens (OR, 1.3; 95% CI, 1.1-1.7) than monotherapy, and among progestogen users than estrogen users as for monotherapy. Furthermore, vaginal, subcutaneous implant seems to be associated with a higher risk of meningioma compared with oral administration although no significance had been reached.

CONCLUSION

This case-control study provides evidence that hormone use for an HRT purpose might constitute the development and growth of meningioma as an independent risk factor, especially for combination therapy and/or long-term users, which supports that meningioma might be a hormone-sensitive tumor.

Meningiomas Display a Specific Immunoexpression Pattern in a Rostrocaudal Gradient: An Analysis of 366 Patients

BACKGROUND

Meningiomas are heterogeneous, with differences in anatomical, histopathological, and clinical characteristics. Such spatial variability in meningioma biology is thought to result from differences in the expression of critical developmental regulators. We hypothesized that the variability in meningioma biology would follow gradients such as in embryology and tested a cohort of 366 meningiomas for histopathological and immunohistochemical gradients.

METHODS

The medical records from 366 patients treated for meningiomas from 2003 to 2016 were retrospectively analyzed for age, gender, anatomical localization, recurrence-free survival, overall survival, histopathological diagnosis, and immunohistochemistry findings for 6 markers: epithelial membrane antigen (EMA), progesterone receptor (PR), CD34, S100, p53, and Ki-67 labeling index.

RESULTS

EMA, PR, S100, p53, and CD34 were expressed in 94%, 73%, 49%, 26%, and 23% of the tumors, respectively. p53 expression correlated positively with Ki-67 and World Health Organization (WHO) grade (r_τ = 0.31 and r_τ = 0.4, respectively). PR positivity correlated inversely with S100, p53, Ki-67, and WHO grade (r_τ = -0.19, r_τ = -0.14, r_τ = -0.15, and r_τ = -0.16, respectively). All secretory meningiomas were positive for EMA and PR and negative for S100, and this pattern exhibited a rostrocaudal gradient. The overall proportion of EMA⁺PR⁺S100^- cases was significantly lower in the cranial vault (30.3%) than in the skull base (45.89%; P = 0.021). The proportion of WHO grade II-III tumors was greater in cranial vault than in skull base meningiomas.

CONCLUSIONS

Unsupervised methods detected an association between the anatomical location and tumor biology in meningiomas. Unlike the categorical associations that former studies had indicated, the present study revealed a rostrocaudal gradient in both the cranial vault and the skull base, correlating with human developmental biology.

Lumbar intraspinal microcystic/reticular schwannoma: Case report and literature review

RATIONALE

Microcystic/reticular schwannoma (MRS) is a rare histological variant of schwannoma which was initially described in 2008 with a predilection for the visceral organs. This distinct tumor had been reported to mainly affect gastrointestinal tract, subcutaneous and soft tissue, various glands and head and neck region. However, MRS involving spine is extremely rare.

PATIENT CONCERNS

The authors report the first case of MRS occurring in the lumbar (L) spinal canal of a 40-year-old male who presented with continuous pain and numbness in both feet for 2.5 years. Physical examination revealed weakness of lower extremities and hyperalgesia of both feet.

DIAGNOSES AND INTERVENTIONS

The findings of pre-operative investigation were suspicious for either a schwannoma or a spinal meningioma. Accordingly, total laminectomy, complete tumor resection, instrumentation and spinal fusion were performed. Post-operative histopathologic examination revealed a well-encapsulated neoplasm with reticular and microcystic growth pattern. Antoni A and Antoni B regions, Verocay bodies and hyalinized blood vessels were observed. And cytologic atypia, necrosis or mitosis was absent. Immunohistochemically, the tumor cells showed strong and diffuse positivity for S-100 as well as SOX 10. Therefore, a histopathological diagnosis of MRS was finally made.

OUTCOMES

The patient remains well with no evidence of recurrence at a 22-month follow-up.

LESSONS

This is the first case of MRS which is located in the L spinal canal. Awareness of this distinctive entity is helpful in preventing diagnostic pitfalls and making correct treatment strategies.

Progesterone Receptor Is Responsible for Benign Biology of Skull Base Meningioma

OBJECTIVE

Many studies have been performed to evaluate the roles of estrogen receptor and progesterone receptor (PGR) in meningiomas, but their influence on tumor behavior remains unclear.

METHODS

We retrospectively analyzed patients with meningioma who underwent surgical resection at our institute. Patients with data for immunohistochemical staining of estrogen receptor, PGR, and Ki-67 were included.

RESULTS

The study included 161 patients comprising 61 skull base and 100 non-skull base meningiomas. Histologically, the number of patients with World Health Organization (WHO) grade I, II, and III disease were 132 (82.0%), 22 (14.7%), and 7 (4.4%), respectively. Tumor recurrence was observed in 21 (13.0%). Negative PGR, high Ki-67 index, incomplete resection, and WHO grade II or III were significantly correlated with tumor recurrence and shorter recurrence-free survival. Skull base meningiomas were difficult to remove entirely; 31 patients (50.8%) with skull base and 77 patients (77.0%) with non-skull base meningiomas had overall complete removal (P = 0.0006). Ki-67 indices, proportion of WHO grade II or III, and recurrence rate or recurrence-free survival did not differ between the tumor locations. The only difference was the proportion of patients with positive PGR, which was significantly higher for skull base meningiomas (61.5 ± 33.4% vs. 42.2 ± 35.7%, P = 0.0009).

CONCLUSIONS

Although skull base meningiomas are often incompletely resected, there were no differences in recurrence-free survival or recurrence rate between skull base and non-skull base meningiomas. As the Ki-67 index and WHO grade were not different between these locations, the high rate of positive PGR may be responsible for the benign biology of skull base meningiomas.

Expression and clinical value of EGFR in human meningiomas

Background

Meningiomas are common intracranial tumors in humans that frequently recur despite having a predominantly benign nature. Even though these tumors have been shown to commonly express EGFR/c-erbB1 (epidermal growth factor receptor), results from previous studies are uncertain regarding the expression of either intracellular or extracellular domains, cellular localization, activation state, relations to malignancy grade, and prognosis.

Aims

This study was designed to investigate the expression of the intracellular and extracellular domains of EGFR and of the activated receptor as well as its ligands EGF and TGFα in a large series of meningiomas with long follow-up data, and investigate if there exists an association between antibody expression and clinical and histological data.

Methods

A series of 186 meningiomas consecutively operated within a 10-year period was included. Tissue microarrays were constructed and immunohistochemically analyzed with antibodies targeting intracellular and extracellular domains of EGFR, phosphorylated receptor, and EGF and TGFα. Expression levels were recorded as a staining index (SI).

Results

Positive immunoreactivity was observed for all antibodies in most cases. There was in general high SIs for the intracellular domain of EGFR, phosphorylated EGFR, EGF, and TGFα but lower for the extracellular domain. Normal meninges were negative for all antibodies. Higher SIs for the phosphorylated EGFR were observed in grade II tumors compared with grade I (p = 0.018). Survival or recurrence was significantly decreased in the time to recurrence analysis (TTR) with high SI-scores of the extracellular domain in a univariable survival analysis (HR 1.152, CI (1.036–1.280, p = 0.009)). This was not significant in a multivariable analysis. Expression of the other antigens did not affect survival.

Conclusion

EGFR is overexpressed and in an activated state in human meningiomas. High levels of ligands also support this growth factor receptor system to be involved in meningioma tumorigenesis. EGFR may be a potential candidate for targeted therapy.

An analysis of prognostic factors associated with recurrence in the treatment of atypical meningiomas

Background

There has been increased reporting of atypical meningioma (grade II) since the World Health Organization reclassification in 2000, and the use of postoperative radiation therapy (RT) in the treatment of these tumors is controversial. We evaluated patients treated at our institution to identify patient subgroups with increased risk of recurrence that may benefit from adjuvant RT.

Methods and materials

We retrospectively assessed 50 patients treated for World Health Organization grade II meningiomas between March 2000 and February 2013. Sex, race, age of diagnosis, tumor location, performance status, size of tumor, MIB-1 index, resection status, and RT were recorded. Patient follow-up, recurrence, and vital status were measured to assess 3-year overall survival (OS) and recurrence free survival (RFS).

Results

The median follow-up was 37 months (range, 1-148). Female sex was associated with decreased RFS compared with male sex (86.1% vs 100%, P = .047). Subtotal resection demonstrated both inferior RFS (67.5% vs 96.6%, P = .025) and OS compared with gross total resection (70.0% vs 100%, P < .001). Tumors >4.5 cm had worse RFS than tumors ≤4.5 cm (85.4% vs 100%, P = .025). Patient OS was lower in tumors with an MIB-1 index >5% than ≤5% (89.7% vs 100%, P = .008). Eastern Cooperative Oncology Group 2-4 negatively impacted OS relative to patients with an Eastern Cooperative Oncology Group 0-1 (66.7% vs 100%, P < .001).

Conclusions

Significantly higher rates of recurrence occurred in female sex, subtotal resection, and tumors larger than 4.5 cm. Further studies are needed to confirm these findings and determine whether patients without any of these risk factors can undergo surgical resection without adjuvant radiation therapy.

Correlation of leptin receptor expression with BMI in differential grades of human meningiomas

Meningioma is one of the most common primary brain tumor, especially in postmenopausal women. The most important risk factors include radiation, primary head injury or genetic alterations, however it is currently unclear why postmenopausal women are predominantly affected. The aim of the present study was to evaluate leptin receptor (LEPR) expression and body mass index (BMI) in patients with meningiomas of differential grades. Specimens of 158 meningiomas were classified as either G1 (low-grade meningiomas, n=114) or G2/G3 (high-grade meningiomas, n=44). Immunohistochemistry was performed to assess LEPR expression. The mean BMIs of the female and male patient groups were 28.43±5.29 and 23.93±4.66, respectively. Mean BMI was significantly higher in the female group, by ~4.50 kg/m2. Patient age significantly correlated with LEPR expression, with the highly positive (++) and positive (+) groups having mean ages of 62.3±12.07 and 52.3±13.04, respectively. A strong positive correlation (r=0.73) was observed between leptin receptor expression and BMI, with the LEPR (++) group having a mean BMI of 30.11±4.49, compared to 22.12±2.48 for the LEPR (+) group. Furthermore, in the low-grade meningioma group, mean BMI was higher in female patients than male patients (28.13±5.54 and 25.38±4.57, respectively; P=0.01). Additionally, there was strong positive correlation between BMI and leptin receptor expression in the low-grade meningioma group (r=0.69). For the high-grade meningioma group, mean BMI was 29.49±4.26 and 21.76±3.98 in female and male patients, respectively, and LEPR expression strongly correlated with BMI in this group (r=0.80). The present study demonstrates a correlation between patient BMI, age, and LEPR expression status in low- and high-grade meningiomas. Our results indicate that in addition to endogenous hormones, such as estrogen or progesterone, or fatty tissue-associated proinflammatory cytokines, LEPR expression status may be a risk factor for meningioma growth and progression.

The Role of Mifepristone in Meningiomas Management: A Systematic Review of the Literature

OBJECTIVES

We performed a systematic literature review to analyze the clinical application and the safety of mifepristone, a prominent antiprogesterone agent, in meningioma patients.

MATERIALS AND METHODS

A systematic search was performed through Medline, Cochrane, and clinicaltrials.gov databases from 1960 to 2014. Study Selection. Studies were selected through a PICO approach. Population was meningioma patients, meningioma cells cultures, and animal models. Intervention was mifepristone administration. Control was placebo administration or any other drug tested. Outcomes were clinical and radiological responsiveness, safety profile, and cell growth inhibition.

RESULTS

A total of 7 preclinical and 6 clinical studies and one abstract were included. Encouraging results were found in preclinical studies. Concerning clinical studies, the response rate to mifepristone in terms of radiological regression and symptomatic improvement/stability in patients with inoperable meningioma was low. In meningiomatosis, favorable preliminary results were recorded. The safety profile was good. Limitations were as follows. The tumoral expression of progesterone receptors was not analyzed systematically in every study considered.

CONCLUSIONS

No clear evidence exists to recommend mifepristone in inoperable meningiomas. Preliminary encouraging results were found in diffuse meningiomatosis. Mifepristone is a well-tolerated treatment. Patients' selection and hormonal profile analysis in meningiomas are fundamental for a better understanding of its benefit. Multicenter placebo-controlled trials are required.

Canine brain tumours: a model for the human disease?

Canine brain tumours are becoming established as naturally occurring models of disease to advance diagnostic and therapeutic understanding successfully. The size and structure of the dog's brain, histopathology and molecular characteristics of canine brain tumours, as well as the presence of an intact immune system, all support the potential success of this model. The limited success of current therapeutic regimens such as surgery and radiation for dogs with intracranial tumours means that there can be tremendous mutual benefit from collaboration with our human counterparts resulting in the development of new treatments. The similarities and differences between the canine and human diseases are described in this article, emphasizing both the importance and limitations of canines in brain tumour research. Recent clinical veterinary therapeutic trials are also described to demonstrate the areas of research in which canines have already been utilized and to highlight the important potential benefits of translational research to companion dogs.

Evidence for involvement of steroid receptors and coactivators in neuroepithelial and meningothelial tumors

Steroid receptors such as androgen receptor (AR) and estrogen receptors (ER) ER-α and ER-β, and their receptor coactivators (steroid receptor coactivator, SRC) are widely localized in the brain. Although previous studies have investigated the expression of steroid receptors in brain tumors like astrocytoma, the studies on the expression of steroid receptors and SRCs in other brain tumors are lacking. Here, we investigated the expression of AR, ERs, and SRCs in neuroepithelial (medulloblastoma, ependymoma, oligodendroglioma) and meningothelial meningioma using tissue microarray immunohistochemistry. Compared to normal brain tissue, we found that the expression of SRC-1, SRC-3, and ER-α significantly decreased in meningothelial tumor and neuroepithelial tumor, suggesting that the SRC-1/SRC-3 levels may be regulated by ER-α. Moreover, the levels of AR strongly correlated to the levels of ER-β. Furthermore, correlation was also detected between SRC-3 and AR in neuroepithelial tumor, and between ER-α and ER-β in meningothelial tumor. In addition, the decreased ratio of SRC-1/SRC-3 was associated with an increase of ER-β in neuroepithelial tumor. These results indicate that expressions of different steroid receptors and activators may be tumor type dependent. While AR, ER-α, and ER-β may be involved in the pathogenesis of meningothelial tumor, SRCs/ER-β axis and SRC-3/AR axis may play a role in the pathogenesis of neuroepithelial tumor.

Pathology and molecular genetics of meningioma: recent advances

Meningiomas are the most common intracranial primary neoplasm in adults. Although the spectrum of clinical and molecular genetic issues regarding meningiomas remains undefined, novel genetic alterations that are associated with tumor morphology, malignancy, or location have recently been discovered. This review focuses on recent advances in understanding of the heterogenous pathology of meningiomas, particularly on associations between the clinical, histological, etiological, epidemiological, and molecular genetical aspects of the neoplasm.

Successful treatment of multiple intracranial meningiomas with the antiprogesterone receptor agent mifepristone (RU486)

BACKGROUND

Meningiomas are the most frequent primary brain tumor in adults. Evidence suggests that female sex hormones play a role in the meningioma tumorigenesis. In particular, progesterone, has a receptor (PR) that is highly expressed in the majority of grade I meningiomas. Multiple meningiomas (diffuse meningiomatosis) are less frequent, but have a higher female predominance and a higher PR expression. They are, therefore, attractive candidates for anti-PR therapy.

METHODS

We treated three consecutive women with multiple meningiomas with mifepristone (RU 486). It is a synthetic steroid with high affinity for both progesterone and glucocorticoid receptors.

RESULTS

The treatment was well tolerated, and we observed an important and long-lasting clinical (3/3) and radiological response (2/3) or stabilisation. All the three patients are now stable after five to nine years of treatment.

CONCLUSIONS

These encouraging results strongly support a prospective clinical trial in this preselected population.