Expression of androgen and progesterone receptors in primary human meningiomas

Nomogram for predicting cardiovascular disease mortality in patients with meningioma: a competing risk analysis

Cancer patients may have increased risk of cardiovascular mortality than general population. We designed this study to investigate the incidence and risk factors of cardiovascular mortality in meningioma patients. Meningioma patients recorded in Surveillance Epidemiology and End Results (SEER) database between 2004 and 2016 were eligible for this study. The standardized mortality ratio (SMR) was calculated to present the relative risk of cardiovascular mortality (ICD-10 codes I00-I99) in meningioma patients compared with general population. Fine-Gray subdistribution proportional hazards regression was performed to identify risk factors of cardiovascular mortality and construct nomogram for predicting cardiovascular-specific survival in meningioma patients. Among 94,067 meningioma patients included in this study, 6145 (6.5%) and 16549 (17.6%) patients died due to cardiovascular diseases and other causes, respectively. The cardiovascular disease-related SMR of included meningioma patients was 25.31 compared with the general population. Results of multivariate competing risk analysis showed that age, male gender, race, marital status, insurance status, tumor size, tumor location, histologic type, and surgery options were risk factors of cardiovascular mortality. The C-index of our constructed nomogram for predicting cardiovascular specific survival was 0.730 (0.712-0.748) and 0.726 (0.696-0.756) in training cohort and validation cohort, respectively. Incorporating demographic and clinical variables, the nomogram we constructed is effective in predicting cardiovascular mortality in meningioma patients and could guide physicians to reasonably control clinical risk factors of cardiovascular mortality in meningioma patients.

Respective roles of Pik3ca mutations and cyproterone acetate impregnation in mouse meningioma tumorigenesis

Despite their rarity, PIK3CA mutations in meningiomas have raised interest as potentially targetable, ubiquitous mutations owing to their presence in sporadic benign and malignant tumors but also in hormone-related cases. Using new genetically engineered mouse models, we here demonstrate that Pik3ca mutations in postnatal meningeal cells are sufficient to promote meningioma formation but also tumor progression in mice. Conversely, hormone impregnation, whether alone or in association with Pik3ca and Nf2 mutations, fails to induce meningioma tumorigenesis while promoting breast tumor formation. We then confirm in vitro the effect of Pik3ca mutations but not hormone impregnation on the proliferation of primary cultures of mouse meningeal cells. Finally, we show by exome analysis of breast tumors and meninges that hormone impregnation promotes breast tumor formation without additional somatic oncogenic mutation but is associated with an increased mutational burden on Pik3ca-mutant background. Taken together, these results tend to suggest a prominent role of Pik3ca mutations over hormone impregnation in meningioma tumorigenesis, the exact effect of the latter is still to be discovered.

Identification of key genes and pathways associated with resting mast cells in meningioma

BACKGROUND

To identify candidate key genes and pathways related to resting mast cells in meningioma and the underlying molecular mechanisms of meningioma.

METHODS

Gene expression profiles of the used microarray datasets were obtained from the Gene Expression Omnibus (GEO) database. GO and KEGG pathway enrichments of DEGs were analyzed using the ClusterProfiler package in R. The protein-protein interaction network (PPI), and TF-miRNA- mRNA co-expression networks were constructed. Further, the difference in immune infiltration was investigated using the CIBERSORT algorithm.

RESULTS

A total of 1499 DEGs were identified between tumor and normal controls. The analysis of the immune cell infiltration landscape showed that the probability of distribution of memory B cells, regulatory T cells (Tregs), and resting mast cells in tumor samples were significantly higher than those in the controls. Moreover, through WGCNA analysis, the module related to resting mast cells contained 158 DEGs, and KEGG pathway analysis revealed that the DEGs were dominant in the TNF signaling pathway, cytokine-cytokine receptor interaction, and IL-17 signaling pathway. Survival analysis of hub genes related to resting mast cells showed that the risk model was constructed based on 9 key genes. The TF-miRNA- mRNA co-regulation network, including MYC-miR-145-5p, TNFAIP3-miR-29c-3p, and TNFAIP3-hsa-miR-335-3p, were obtained. Further, 36 nodes and 197 interactions in the PPI network were identified.

CONCLUSION

The results of this study revealed candidate key genes, miRNAs, and pathways related to resting mast cells involved in meningioma development, providing potential therapeutic targets for meningioma treatment.

Metabolomic Profile of Aggressive Meningiomas by Using High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance

Meningiomas are in most cases benign brain tumors. The WHO 2016 classification defines three grades of meningiomas. This classification had a prognosis value because grade III meningiomas have a worse prognosis value compared to grades I and II meningiomas. However, some benign or atypical meningiomas can have a clinical aggressive behavior. There are currently no reliable markers which allow distinguishing between the meningiomas with a good prognosis and those which may recur. High-resolution magic angle spinning (HRMAS) spectrometry is a noninvasive method able to determine the metabolite profile of a tissue sample. We retrospectively analyzed 62 meningioma samples by using HRMAS spectrometry (43 metabolites). We described a metabolic profile defined by a high concentration for acetate, threonine, N-acetyl-lysine, hydroxybutyrate, myoinositol, ascorbate, scylloinositol, and total choline and a low concentration for aspartate, glucose, isoleucine, valine, adenosine, arginine, and alanine. This metabolomic signature was associated with poor prognosis histological markers [Ki-67 ≥ 40%, high histological grade and negative progesterone receptor (PR) expression]. We also described a similar metabolomic spectrum between grade III and grade I meningiomas. Moreover, all grade I meningiomas with a low Ki-67 expression and a positive PR expression did not have the same metabolomic profile. Metabolomic analysis could be used to determine an aggressive meningioma in order to discuss a personalized treatment. Further studies are needed to confirm these results and to correlate this metabolic profile with survival data.

Grade III meningioma with gastro-intestinal tract and brain metastases: case report and review of the literature

BACKGROUND

Meningioma is the most common adult primary intracranial tumor. Malignant meningioma is a rare variant of meningioma. The prognosis for the patients with these tumors is poor, due to the tumor's capacity for relapse and to develop distant metastases. These tumors can present the same evolutionary course as aggressive carcinoma.

CASE DESCRIPTION

We report the case of distant brain and gastro-intestinal tract (GIT) metastases. A 78-year-old patient developed malignant meningioma with a Ki-67 proliferative index of 40%. According to guidelines, surgery followed by postoperative radiotherapy (RT) was performed. Three months after the end of RT, he presented histologically proven meningioma distant brain and GIT metastases.

CONCLUSIONS

To our knowledge, this is the first case of meningioma GIT metastases. Also, we report the difficulty to confirm the diagnosis of meningioma metastases. Indeed, malignant meningioma has the same histopathological features as melanoma or carcinoma. The standard of care for the management of malignant meningioma is gross total surgery followed by postoperative radiotherapy. Metastatic meningioma is uncommon and no guidelines for the management of recurrent or metastatic meningioma have yet been published. However, several studies reported systemic therapeutic options such as antibody against VEGF, somatostatin analogs, PDGF-R, and VEGF-R tyrosine kinase inhibitors, in the case of recurrent or metastatic meningioma. We also made a review of the actual literature of systemic treatment options for metastatic meningioma.

The Role of Endonasal Endoscopic Optic Nerve Decompression as the Initial Management of Primary Optic Nerve Sheath Meningiomas

Background  The management of optic nerve sheath meningiomas (ONSMs) remains controversial. Surgical decompression through traditional resective techniques has been associated with significant morbidity. While radiation therapy, the current modality of choice is not exempt of risks. Transnasal endoscopic optic nerve decompression (EOND) offers a direct route to the orbit, optic canal, and orbital apex, providing a minimally invasive alternative. Objective  The main objective of this article is to assess EOND as the initial management of symptomatic patients with primary ONSM. Methods  Patients with ONSMs without a history of radiotherapy who underwent EOND were retrospectively reviewed. Postoperative imaging, duration of follow-up, and visual outcomes at the last ophthalmology visit were assessed. Results  Four women (age range 25-63 years) with primary ONSMs that underwent EOND were identified. All patients displayed subjective and objective baseline signs of vision loss. Additionally, baseline proptosis, diplopia, optic nerve atrophy, and ocular pain were identified. In none of the cases, the optic nerve sheath was breached. Following EOND, all patients deferred treatment with adjuvant radiotherapy. At a mean postoperative follow-up of 14 months, all patients were clinically stable without evidence of disease progression on imaging or physical examination. At last ophthalmologic evaluation, three out of four showed objective improvements from baseline visual acuity and visual field (remaining patient had baseline optic nerve atrophy). Conclusion  These results suggest that EOND could be a viable initial treatment modality of selected primary ONSM cases. Further studies are warranted to determine long-term efficacy and its role in a stepwise progression of management, preceding radiotherapy.

Progesterone Receptor Synthesis in Human Meningiomas: Relation to the Estrogen-Induced Proteins pS2 and Cathepsin-D and Influence of Epidermal Growth Factor, Forskolin and Phorbol Ester in vitro

Autonomous expression of progesterone receptors (PR) in human meningiomas is well established. To evaluate whether, similar to progesterone receptors, other estrogen-inducible proteins are also autonomously expressed in meningiomas, concentrations of pS2 and cathepsin-D (Cath-D) were measured in 52 meningiomas. No pS2 protein was detectable in 52/52 tested meningiomas. The Cath-D protein was measurable in all 52 meningiomas, but the mean concentration of Cath-D in meningioma cytosols was 2.4-fold lower than that of a group of 54 breast tumors (p < 0.001). These results indicate that autonomous expression is a PR-related rather than an estrogen receptor-related phenomenon and, consequently, that estradiol is probably not responsible for PR synthesis in human meningiomas. To evaluate the role of other, non-estradiol-dependent signalling pathways in PR synthesis, the effects of EGF, Forskolin and phorbol ester on PR synthesis were tested in vitro. No PR was detectable after the addition of EGF to six different primary cultures. Forskolin and TPA addition caused a morphological change in meningioma cells, but did not induce PR or pS2 synthesis in two different primary meningioma cultures. We conclude that PR synthesis in human meningiomas cannot be triggered by switching on the signalling pathways activated by these growth factors.

Diagnosis and Treatment of Orbital Optic Nerve Sheath Meningioma

BACKGROUND

Primary and secondary optic nerve sheath meningiomas (ONSMs) are neoplasms that account for a large proportion of optic nerve and orbital tumors. The diagnosis is not always straightforward and is based on the appropriate clinical findings and neuroimaging. Biopsy or surgical intervention may occasionally be necessary but is associated with significant morbidity.

METHODS

Issues related to clinical signs and symptoms, diagnosis, natural history, and treatment strategies are reviewed based on a review of published literature.

RESULTS

Diagnosis is usually based on radiographic and clinical findings. Biopsies are not obtained in most cases, thus adding further to the bias of possible misdiagnosis in all reported case series that do not have the benefit of histopathologic confirmation. Natural history typically shows inexorable progression in most cases, although long periods of stability are occasionally reported. Treatment options include observation, radiation alone, surgery alone, and combined radiation and surgery. The optimum timing of interventional therapy and radiation are evolving.

CONCLUSIONS

After serial examination documents new decline in acuity and/or visual field, fractionated radiotherapy appears most likely to preserve visual function and is a valid treatment approach for primary orbital ONSM. Tumor enlargement, as determined by serial imaging, may also provide an indication to begin radiotherapy.

An Overview of Anterior Skull Base Meningiomas and the Endoscopic Endonasal Approach

Meningiomas represent 30% of all primary brain tumors. Anterior skull base meningiomas represent 8.8% of all meningiomas. Surgical resection is a main treatment option for tumors that are symptomatic and/or growing. Recurrence is directly related to the extent of resection of the tumor, the dural attachment, and pathologic bone. Endoscopic endonasal approaches represent an important addition to the treatment armamentarium for skull base meningiomas. This article provides an overview of meningiomas, with a focus on those of the anterior skull base and their management.

Mast cells in meningiomas and brain inflammation

Background

Research focus in neuro-oncology has shifted in the last decades towards the exploration of tumor infiltration by a variety of immune cells and their products. T cells, macrophages, B cells, and mast cells (MCs) have been identified.

Methods

A systematic review of the literature was conducted by searching PubMed, EMBASE, Google Scholar, and Turning Research into Practice (TRIP) for the presence of MCs in meningiomas using the terms meningioma, inflammation and mast cells.

Results

MCs have been detected in various tumors of the central nervous system (CNS), such as gliomas, including glioblastoma multiforme, hemangioblastomas, and meningiomas as well as metastatic brain tumors. MCs were present in as many as 90 % of all high-grade meningiomas mainly found in the perivascular areas of the tumor. A correlation between peritumoral edema and MCs was found.

Interpretation

Accumulation of MCs in meningiomas could contribute to the aggressiveness of tumors and to brain inflammation that may be involved in the pathogenesis of additional disorders.

Long-term natural history of neurofibromatosis Type 2-associated intracranial tumors

OBJECT

Neurofibromatosis Type 2 (NF2) is a heritable tumor predisposition syndrome that leads to the development of multiple intracranial tumors, including meningiomas and schwannomas. Because the natural history of these tumors has not been determined, their optimal management has not been established. To define the natural history of NF2-associated intracranial tumors and to optimize management strategies, the authors evaluated long-term clinical and radiographic data in patients with NF2.

METHODS

Consecutive NF2 patients with a minimum of 4 years of serial clinical and MRI follow-up were analyzed.

RESULTS

Seventeen patients, 9 males and 8 females, were included in this analysis (mean follow-up 9.5±4.8 years, range 4.0-20.7 years). The mean age at initial evaluation was 33.2±15.5 years (range 12.3-57.6 years). Patients harbored 182 intracranial neoplasms, 164 of which were assessable for growth rate analysis (18 vestibular schwannomas [VSs], 11 nonvestibular cranial nerve [CN] schwannomas, and 135 meningiomas) and 152 of which were assessable for growth pattern analysis (15 VSs, 9 nonvestibular CN schwannomas, and 128 meningiomas). New tumors developed in patients over the course of the imaging follow-up: 66 meningiomas, 2 VSs, and 2 nonvestibular CN schwannomas. Overall, 45 tumors (29.6%) exhibited linear growth, 17 tumors (11.2%) exhibited exponential growth, and 90 tumors (59.2%) displayed a saltatory growth pattern characterized by alternating periods of growth and quiescence (mean quiescent period 2.3±2.1 years, range 0.4-11.7 years). Further, the saltatory pattern was the most frequently identified growth pattern for each tumor type: meningiomas 60.9%, VSs 46.7%, and nonvestibular schwannoma 55.6%. A younger age at the onset of NF2-related symptoms (p=0.01) and female sex (p=0.05) were associated with an increased growth rate in meningiomas. The identification of saltatory growth in meningiomas increased with the duration of follow-up (p=0.01).

CONCLUSIONS

Neurofibromatosis Type 2-associated intracranial tumors most frequently demonstrated a saltatory growth pattern. Because new tumors can develop in NF2 patients over their lifetime and because radiographic progression and symptom formation are unpredictable, resection may be best reserved for symptom-producing tumors. Moreover, establishing the efficacy of nonsurgical therapeutic interventions must be based on long-term follow-up (several years).

Molecular biology of unreresectable meningiomas: implications for new treatments and review of the literature

Even though meningiomas are most often benign tumors, they can be locally invasive and can develop in locations that prevent surgical treatment. The molecular and biologic factors underlying meningioma development are only now beginning to be understood. Genetic factors such as mutations in the neurofibromatosis-2 gene and in chromosomes 1, 9, and 10 play important roles in meningioma development and may be responsible for atypical tumors in some cases. Cellular factors such as telomerase activation and tyrosine kinase receptor mutations may also play an important role. Finally, autocrine and paracrine factors including epidermal growth factor receptor, platelet-derived growth factor-1, and fibroblast growth factor have been implicated in the development of some tumors. Although the relationship between the various factors implicated in tumor development is unknown, understanding these factors will be critical in the treatment of malignant or surgically inaccessible tumors.

Epidemiology and etiology of meningioma

Although most meningiomas are encapsulated and benign tumors with limited numbers of genetic aberrations, their intracranial location often leads to serious and potentially lethal consequences. They are the most frequently diagnosed primary brain tumor accounting for 33.8% of all primary brain and central nervous system tumors reported in the United States between 2002 and 2006. Inherited susceptibility to meningioma is suggested both by family history and candidate gene studies in DNA repair genes. People with certain mutations in the neurofibromatosis gene (NF2) have a very substantial increased risk for meningioma. High dose ionizing radiation exposure is an established risk factor for meningioma, and lower doses may also increase risk, but which types and doses are controversial or understudied. Because women are twice as likely as men to develop meningiomas and these tumors harbor hormone receptors, an etiologic role for hormones (both endogenous and exogenous) has been hypothesized. The extent to which immunologic factors influence meningioma etiology has been largely unexplored. Growing emphasis on brain tumor research coupled with the advent of new genetic and molecular epidemiologic tools in genetic and molecular epidemiology promise hope for advancing knowledge about the causes of intra-cranial meningioma. In this review, we highlight current knowledge about meningioma epidemiology and etiology and suggest future research directions.

The association of breast cancer and meningioma in men and women

OBJECTIVE

An association between breast cancer and intracranial meningioma has been described in women. We sought to determine whether this connection exists in men as well, hypothesizing that causes unrelated to sex may be responsible.

METHODS

We queried state cancer registries that recorded data on breast cancer and meningioma. International Classification of Diseases for Oncology codes for breast cancer and meningioma were used. The incidence rate of the second primary tumor was compared between identified meningioma and breast cancer cohorts and the general population for each sex.

RESULTS

Five state registries collected data on men and women from 1995 to 2003. The incidence of meningioma was 2.6 and 0.96 (cases per 100,000) for women and men, respectively, during this period. The incidence of breast cancer was 61 and 0.69 (cases per 100,000) for women and men, respectively, during this period. One man and 439 women were diagnosed with both diseases. The standardized incidence ratio was used to determine the magnitude of association between breast cancer and meningioma. During the study period, the standardized incidence ratio indicated a stronger than expected association between breast cancer and meningioma in women, regardless of which disease was diagnosed first. In every year except one, the standardized incidence ratio indicated no association between breast cancer and meningioma in men, regardless of which disease was diagnosed first.

CONCLUSION

Our results support a strong association between meningioma and breast cancer in women. Conversely, we were unable to show as strong an association in men. This suggests that the connection between these diseases may be dependent on sex.

Gonadotropin-releasing hormone (GnRH) and its receptor in human meningiomas

OBJECTIVE

Meningiomas are the most common neoplasms of the central nervous system and are more frequent in women than in men. Many studies have been conducted to determine whether the progesterone receptor (PR) and estrogen receptor (ER) are present or absent in meningiomas. No previous studies, however, have investigated the status (presence or absence) of gonadotropin-releasing hormone (GnRH) and its receptor (GnRH-R), two major factors related to PR and ER, in meningiomas. This study aims to determine the status of GnRH and GnRH-R and to elucidate the correlations of GnRH and GnRH-R with PR, ER, and clinical features in meningiomas.

METHODS

Eighty-two specimens of human meningiomas were obtained for immunohistochemical analysis with anti-GnRH, anti-GnRH-R, anti-PR, anti-ER, and anti-Ki-67 (MIB-1) antibodies, and for RT-PCR analysis of the mRNA expressions of GnRH and GnRH-R. Correlations of GnRH and GnRH-R with PR, ER, Ki-67, and clinical features such as age, sex, tumor grade, and tumor histology were assessed.

RESULTS

Seventy-eight (95.1%) of the 82 meningiomas reacted positively in the cytoplasm for the GnRH-R. Forty-nine (59.8%) of the 82 cases reacted positively in the cytoplasm for the GnRH. The positive immunoreactivity for GnRH-R and GnRH was confirmed by the RT-PCR analyses of mRNA. Forty-seven (96%) of the 49 cases with positive immunoreactivity for GnRH-R also had positive immunoreactivity for GnRH. PR expression was higher in the tumors positive for GnRH-R (p=0.002), and a significantly higher proportion of tumors from male patients exhibited positive immunoreactivity for GnRH (p=0.02). No significant correlations were found between the status of GnRH-R or GnRH with other clinicopathological features.

CONCLUSION

Over half of meningiomas may be regulated by GnRH-GnRH-R expression in an autocrine fashion. This unique expression profile of GnRH and GnRH-R may open the way to the development of GnRH analogs as a treatment tool in the future.

Specific genes expressed in association with progesterone receptors in meningioma

An association between hormones and meningioma has been postulated. No data exist that examine gene expression in meningioma by hormone receptor status. The data are surgical specimens from 31 meningioma patients undergoing neurosurgical resection at Brigham and Women's Hospital from March 15, 2004 to May 10, 2005. Progesterone and estrogen hormone receptors (PR and ER, respectively) were measured via immunohistochemistry and compared with gene expression profiling results. The sample is 77% female with a mean age of 55.7 years. Eighty percent were grade 1 and the mean MIB was 6.2, whereas 33% and 84% were ER+ and PR+, respectively. Gene expression seemed more strongly associated with PR status than with ER status. Genes on the long arm of chromosome 22 and near the neurofibromatosis type 2 (NF2) gene (22q12) were most frequently noted to have expression variation, with significant up-regulation in PR+ versus PR- lesions, suggesting a higher rate of 22q loss in PR- lesions. Pathway analyses indicated that genes in collagen and extracellular matrix pathways were most likely to be differentially expressed by PR status. These data, although preliminary, are the first to examine gene expression for meningioma cases by hormone receptor status and indicate a stronger association with PR than with ER status. PR status is related to the expression of genes near the NF2 gene, mutations in which have been identified as the initial event in many meningiomas. These findings suggest that PR status may be a clinical marker for genetic subgroups of meningioma and warrant further examination in a larger data set.

Meningiomas: causes and risk factors

Meningiomas are among the most common primary intracranial tumors. Although the vast majority of these tumors are considered histologically benign, the incidence of complications can be high. Few studies have investigated the causes and risk factors for meningioma; this review highlights the current state of knowledge. Gaining a better understanding of the origin of this disease is essential so that treatments and outcomes can be improved and prevention strategies can be developed.

Exogenous hormone use and meningioma risk: what do we tell our patients?

The decision to commence or continue use of hormone replacement therapy or oral contraceptives in women presumed or known to be diagnosed with intracranial meningioma is a common clinical question in neurosurgery. A review of the English-language literature was undertaken to examine the association between the use of exogenous hormones and meningioma risk. Seven publications were identified, 6 of which met criteria for inclusion. No randomized clinical trial data were available, hence, results were collected from 2 population-based case-control studies, 2 hospital-based case-control studies, 1 nested case-control study drawn from a large national cohort, and 1 retrospective cohort study. At present, there is no statistical evidence of an increased risk of meningioma among users of oral contraceptives. Although not definitive, available data suggest an association between the use of hormone replacement therapy and increased meningioma risk. Further evaluation of exogenous hormone use in women with meningioma is needed with particular attention to stratification by hormone (ie, estrogen and/or progesterone) composition, duration of and age at use as well as tumor receptor subtype.

Progesterone and estrogen receptors: opposing prognostic indicators in meningiomas

OBJECT

The preponderance of progesterone receptors (PRs) and the scarcity of estrogen receptors (ERs) in meningiomas are well known. The expression of PRs may relate to tumor grade and recurrence. Cytogenetic abnormalities are associated with aggressive behavior, recurrence, and progression. In this study, the authors focus on the prognostic implications of hormone receptors in meningiomas to help determine the clinical and biological aggressiveness of tumors and their correlations with cytogenetic abnormalities.

METHODS

Two hundred thirty-nine patients with meningiomas were separated into three groups. Group 1 (PR-positive group) comprised patients whose meningiomas displayed expression of PRs alone. Group 2 (receptor-negative group) included patients whose lesions did not have receptors for either progesterone or estrogen. Group 3 (ER-positive group) included patients whose tumors displayed expression of ERs. Clinical and histological findings, proliferative indices, tumor recurrence, and cytogenetic findings were analyzed by performing the Fisher exact test. Compared with the receptor-negative (Group 2) and ER-positive (Group 3) groups, the PR-positive group (Group 1) had a statistically significant lower proliferative index and a smaller number of patients in whom there were aggressive histopathological findings or changes in karyotype. In Groups 1, 2, and 3, the percentages of cases with aggressive histopathological findings were 10, 31, and 33%, respectively; the percentages of cases with chromosomal abnormalities were 50, 84, and 86%, respectively; and the percentages of cases in which there initially was no residual tumor but recurrence was documented were 5, 30, and 27%, respectively. A statistically significant increase in the involvement of chromosomes 14 and 22 was identified in receptor-negative and ER-positive de novo meningiomas, when compared with the PR-positive group. Abnormalities on chromosome 19 were statistically significantly higher in receptor-negative meningiomas than in PR-positive tumors.

CONCLUSIONS

The expression of the PR alone in meningiomas signals a favorable clinical and biological outcome. A lack of receptors or the presence of ERs in meningiomas correlates with an accumulation of qualitative and quantitative karyotype abnormalities, a higher proportional involvement of chromosomes 14 and 22 in de novo tumors, and an increasing potential for aggressive clinical behavior, progression, and recurrence of these lesions. Sex hormone receptor status should routinely be studied for its prognostic value, especially in female patients, and should be taken into account in tumor grading. The initial receptor status of a tumor may change in progression or recurrence of tumor.

Meningioma Mimicking Puerperal Psychosis

BACKGROUND

Meningiomas are slow-growing benign brain tumors. They can be sensitive to sex hormones, increasing in size with pregnancy and leading to clinical presentation either before or immediately after delivery. Initial symptoms and signs can present in the antenatal as well as the postnatal period.

CASE

A patient presented with confusion associated with complaints of déjà vu and auditory hallucinations on day 1 postcesarean delivery. Meningioma was diagnosed by computed tomography and treated successfully with steroids, anticonvulsant, and craniotomy.

CONCLUSION

It is imperative to perform a thorough neurologic examination in a patient who presents with atypical psychiatric symptoms in the antenatal or postpartum period. Neuroimaging should be performed in the presence of any neurologic abnormality to exclude intracranial lesions such as meningioma.

Epidemiology of intracranial meningioma

Meningiomas are the most frequently reported primary intracranial neoplasms, accounting for approximately 25% of all such lesions diagnosed in the United States. Few studies have examined the risk factors associated with a diagnosis of meningioma with two categories of exposure, hormones (both endogenous and exogenous) and radiation, most strongly associated with meningioma risk. Limited data are also available on long-term outcomes for meningioma patients, although it is clear that the disease is associated with significant morbidity and mortality. Recent legislation passed in the United States (The Benign Brain Tumor Cancer Registries Amendment Act [H.R. 5204]) mandates registration of benign brain tumors such as meningioma. This will increase the focus on this disease over the coming years as well as likely increase the reported prevalence of the disease. The increased emphasis on research dedicated to the study of brain tumors coupled with the advent of new tools in genetic and molecular epidemiology make the current era an ideal time to advance knowledge for intracranial meningioma. This review highlights current knowledge of meningioma epidemiology and new directions for research efforts in this field.

Female predominance in meningiomas can not be explained by differences in progesterone, estrogen, or androgen receptor expression

The female predominance in meningioma incidence and association between meningioma and breast cancer suggest that growth of meningiomas is hormone-dependent. There are several discrepancies in literature about the proliferative effect of sex hormones on meningiomas. This study aims to evaluate the hormone receptor status of meningiomas and assess its relation to age, sex, histological grade, recurrence, and proliferation activity. The material was based on consecutive patients operated for meningioma at Tampere University Hospital in 1989-1999. The occurrence of progesterone, estrogen and androgen receptor in patients with primary and recurrent meningiomas was studied immunohistochemically by using specific monoclonal antibodies. Hormonal status was determined in 510 tumor samples. 443 samples were from primary meningiomas and 67 from recurrent tumors. Of the samples, 455 were benign (WHO grade I), 49 atypical (grade II), and 6 malignant (grade III). Of the primary tumor samples, 88% were progesterone receptor positive, 40% were positive for estrogen and 39% for androgen receptors. Grade I meningiomas had significantly higher incidence for estrogen and androgen receptors than higher grade meningiomas. Estrogen positive tumor samples had significantly higher proliferation index than estrogen negative samples. No difference in expression of sex hormone receptors was observed by sexes or age group. Estrogen and androgen receptors may have more influence on the pathogenesis of meningiomas than earlier thought. The higher incidence of meningiomas in women can not be explained by differences of sex hormone receptor expression.

Secretory meningioma: immunohistochemical findings and evaluation of mast cell infiltration

Secretory meningiomas constitute a relatively rare subtype of meningiomas, accounting for only 1.1% at our institution, with a 6:1 predominance of female patients. This study aimed to obtain more information about the immunohistochemical characteristics of this histological entity, and to analyse the effects of histological factors such as the presence of mast cells on the radiological evidence of surrounding tumour oedema that frequently occurred in this subtype of meningioma. Fourteen cases of secretory meningioma were examined. Relevant clinical information was obtained from the patient files. Peritumoural oedema was determined either by CT or MRI scans and graded as small, moderate and severe. In order to perform the quantitative evaluation of mast cells in secretory meningiomas in a comparison with other meningiomas, 14 non-secretory meningiomas were randomly selected and used as a control group. The immunohistochemical staining of carcinoembryonic antigen was positive within the secretory droplets and the cells surrounding them in all cases. Ki 67 (MIB 1) proliferative index mean values were 2.4%, indicating low expression in all secretory meningiomas. Moreover, from our statistical analysis, there is no clear-cut pattern of various types of cytokeratins emerging in secretory meningiomas. The secretory meningiomas were characterized by a significantly increased number of mast cells as compared with non-secretory meningiomas of different grades. As the present clinical findings and laboratory results could not confirm a correlation between mast cell density and radiological evidence of oedema, further studies of mediators are warranted.

Surgical management of tuberculum sellae meningioma in a patient with a twin pregnancy: case report

BACKGROUND

Meningioma in twin pregnancy is rare. The tumor has an accelerated growth during the pregnancy and may enlarge or become symptomatic during this period. This relationship makes management of patients with this tumor quite challenging.

CASE DESCRIPTION

We describe a case of a rapidly deteriorating 35-year-old woman harboring an extensive tuberculum sellae meningioma who underwent craniotomy during the 24th week of pregnancy because of rapid deterioration. The surgical procedure and postoperative period were relatively uneventful.

CONCLUSION

To the best of our knowledge, this is the first reported case of surgical management of a meningioma in a patient carrying a twin pregnancy (one missed abortus). When indicated, craniotomy is a safe and effective treatment option for huge frontobasal tumors during the second trimester of pregnancy.

Progesterone-receptor index in meningiomas: correlation with clinico-pathological parameters and review of the literature

For recurrent and untreatable meningiomas alternative therapies, such as anti-progesterone treatment, have been sought. However, the few clinical studies have not determined progesterone receptor (PgR) expression in most cases, and studies correlating quantitative PgR expression (PgR index) with clinico-pathological variables are scarce. The aim of our study was to assess the PgR indices in a consecutive series of meningiomas and correlate these values with clinico-pathological parameters. We analyzed immunohistochemically 82 consecutive meningioma specimens (73 primary and nine recurrent tumors) for PgR and Ki-67 antigen (MIB-1). The male/female ratio was 1:1.7, and median age at the time of surgery was 57 years (range 29-77 years). The series comprised 55 grade I (subtyped as 36 meningothelial, seven fibrous, nine transitional, two psammomatous, and one angiomatous), 23 grade II, and one grade III meningiomas. Nuclear immunostaining for PgR was positive in 56 meningioma specimens (71%). PgR index was 21.4+/-2.8% (mean +/- SE; range 0-79%). Significantly higher expression was found in male patients in the age group <50 years than in those > or = 60 years and in grade I meningothelial meningiomas than in fibrous and transitional subtypes. There was a trend to lower PgR indices in non-benign meningiomas. Cell proliferation rate (MIB-1 index) was 4.4 +/- 0.4% (mean +/- SE; range 0.3-15.4%). Significantly higher MIB-1 indices were found in male than female patients,in recurrent than primary and in grade II than grade I meningiomas. We observed a trend to higher PgR indices in meningiomas with MIB-1 index <5%. In sum, the highest PgR index in our series was observed in patients under the age of 50 years with WHO grade I meningiomas of the meningothelial subtype and low cell proliferation indices. If hormonal therapy has a direct action on the PgR, these patients should respond best to anti-progesterone treatment. We conclude that PgR index is variable in meningioma, depending on clinical parameters and histopathological features. Stratification of anti-progesterone therapy trials on the basis of PgR index should be considered.

Meningiomas: Updating Basic Science, Management, and Outcome

BACKGROUND

Meningiomas are biologically complex and clinically and surgically challenging. These features, combined with the rewarding potential for cure, make them of great interest to neurologists, neurosurgeons, and neuroscientists alike.

REVIEW SUMMARY

Initially, we review the clinical context of meningiomas, particularly recent changes in histopathological classification, diagnosis, and neuroimaging. Secondly, the underlying basic science as it has evolved over the last decades is summarized. The status of areas recently of intense interest, such as steroid hormone receptors and oncogenic viruses is described. Additionally, emerging areas of great promise, such as cytogenetics and molecular biology are presented. Lastly, we describe recent advances in management. In particular, skull-base surgery, image-guided surgery, and advances in radiotherapy are emphasized. The possible impact of basic research on management and outcome is also outlined.

CONCLUSIONS

Although usually benign and amenable to cure, meningiomas still present significant diagnostic and treatment challenges. Advances in basic science, surgery, and adjuvant therapy are widening the potential for safe, effective, evidence-based management leading to even better outcomes

Hormone receptors in non-malignant meningiomas correlate with apoptosis, cell proliferation and recurrence-free survival

AIMS

A retrospective immunohistochemical and statistical analysis of patients with non-malignant meningiomas was undertaken to determine the correlation of steroid hormone receptor status with apoptosis, tumour cell proliferation, clinicopathological characteristics and prediction of recurrence.

METHODS AND RESULTS

Paraffin sections from 51 primary intracranial totally resected benign and atypical meningiomas were immunohistochemically evaluated for the expression of progesterone (PR), oestrogen (ER) and androgen (AR) receptors, apoptotic rate, Bcl-2, p53 and Ki67 antigens. In addition to the above parameters, the mitotic index and the patients' clinicopathological data were statistically correlated and entered in a recurrence-free survival analysis. A high level of apoptotic cell death was associated with loss of PR expression by logistic regression analysis (P = 0.016). An inverse correlation existed between the mitotic index and PR counts (P = 0.009), while high Ki67 values correlated with increased ARs (P = 0.041). Atypical meningiomas had a lower ER staining score (P = 0.036). Multivariate analysis indicated that the absence of PR and large tumour size were significant factors for shorter disease-free intervals.

CONCLUSIONS

The results suggest that ER expression is lost or reduced in atypical meningiomas, whereas loss of PR expression is an indicator of increased apoptosis and early recurrence. PRs and ARs may also influence tumour cell proliferation.

Luteinizing hormone-releasing hormone agonists and meningioma: a treatment dilemma

The relative contraindication of hormonal therapy for patients with prostate cancer and a history of meningioma has not been widely emphasized. Using immunohistochemistry to determine the presence of hormone receptors in meningioma specimens proved potentially valuable in 2 patients with biochemical recurrence after prostatectomy who were being considered for androgen deprivation therapy. These cases also highlight the need for caution against assuming that skull-based intracranial growths in patients receiving hormonal therapy for prostate cancer are metastatic lesions rather than hormonally induced primary tumors.

Meningioma associated with intraosseous lipoma

Intraosseous lipomas of the skull are quite rare and only eight cases have been reported. The lipoma in our case was different from that in others in that it showed remarkable proliferation of collagen tissue. This is the first report of meningioma occurring after removal of an intraosseous lipoma of the skull. This report concerns a rare case of a 32-year-old female who developed a huge convexity meningioma 11 years after successful removal of intraosseous lipoma of the left frontoparietal bone. The meningioma originated from the convexity where the lipoma had been, and extended intracranially to the sphenoid ridge. The patient underwent surgical exploration showing that the meningioma had invaded the frontoparietal convexity bone and was firmly attached to the coronal suture with a large dural defect. This rare coincidence suggests that proliferative changes of the intraosseous lipoma and meningeal neoplasm may be the result of the same, as yet unknown, mechanism.

Expression of androgen receptor in meningiomas

In order to investigate the expression of androgen receptor (AR) in meningiomas and its relation to tumor proliferative potential, we examined the expression of AR and proliferating cell nuclear antigen (PCNA) by avidine-biotin complex immunohistochemistry in 39 cases of meningiomas. Of the 39 cases of meningiomas, 20(51%) showed positive AR immunoreactivity. The AR expression positivity rates were 31% (6/19) in benign meningiomas, 58% (7/12) in atypical meningiomas, 87.5% (7/8) in malignant meningiomas, respectively. In addition to the tumor cells, cells of microvascular endothelial proliferation were frequently AR positive. Malignant meningiomas had a significantly higher percentage of AR positive cells compared with atypical and benign meningiomas (P < 0.05). The mean proliferating cell nuclear antigen labeling index (PCNA LI) was significantly higher in the malignant meningiomas when compared with atypical meningiomas (P < 0.05) and benign meningiomas (P < 0.05). AR positive meningiomas had higher PCNA LI than AR negative meningiomas (P < 0.05). The expression of AR in tumor tissues was significantly related with PCNA LI. These data indicated that AR in the meningiomas was correlated with histological grade and AR might participate in the growth of these tumors and tumor angiogenesis. The measurement of AR in these tumors may indirectly represent tumor growth potential.

Expression of estrogen receptors alpha and beta in human meningiomas

The predominance of meningiomas in females, their accelerated growth during the luteal phase of the menstrual cycle and during pregnancy; and the association between meningiomas and breast cancer has led to a number of studies examining the potential role of steroids on the growth of meningiomas. It is generally agreed that the majority of meningiomas possess the progesterone and androgen receptor. There are numerous discrepancies in the literature among the results for estrogen receptor (ER). The aim of this study was to examine the expression of ER-alpha mRNA and the recently described novel ER, ER-beta in meningiomas. Using reverse transcription and polymerase chain reaction (RT-PCR) Southern blot analysis thirty-four meningiomas were examined for the presence of ER-alpha and ER-beta. Forty-four percent of meningiomas showed a strong band for ER-beta mRNA and sixty-eight percent of meningiomas showed a strong band for ER-alpha mRNA. The involvement of ER-beta in meningioma biology should be examined further, given the differences in the ER-alpha and ER-beta gene products.

Juxtaorbital en plaque meningiomas. Report of four cases and review of literature

Juxtaorbital spheroid wing or ridge meningiomas are the most common of the basal meningiomas. These are at times meningiomas en plaque, which in most patients do not have significant intracranial component. This article reviews the literature on en-plaque meningiomas and discusses the role of MR imaging and CT in the diagnosis of en-plaque meningiomas of the paraorbital region. The role of fat-suppression, gadolinium-enhanced, T1-weighted MR imaging is emphasized.

Formation of autocrine loops in human cerebral meningioma tissue by leukemia inhibitor factor, interleukin-6, and oncostatin M: inhibition of meningioma cell growth in vitro by recombinant oncostatin M

OBJECT

It has been demonstrated that growth of cerebral meningiomas found in humans is controlled by a variety of factors, including growth factors, aminergic agents, neuropeptides, and steroids. To further our knowledge of this process, the authors investigated the presence and function of the cytokines leukemia inhibitory factor (LIF), interleukin-6 (IL-6), and oncostatin M (OSM) on meningioma cell proliferation.

METHODS

Active transcription of LIF, IL-6, and OSM, their related receptors (LIF-R, IL-6-R, and gp130), and the consecutive signal-transducing molecules (STAT 1, STAT 3, and STAT 5a) were analyzed in reverse transcriptase-polymerase chain reaction experiments. The presence of endogenous LIF, IL-6, and OSM proteins was demonstrated in the supernatant of cultured meningioma cells using the enzyme-linked immunosorbent assay and Western blot experiments, thus indicating an autocrine signaling pathway for all three cytokines. The biological function of all three cytokines was evaluated by studying their effects on meningioma cell growth. Recombinant LIF and IL-6 showed no significant growth modulating effects; however, recombinant OSM decreased meningioma cell growth by 66%. The antiproliferative potency of OSM was demonstrated by cell count experiments, the [3H]thymidine incorporation assay, and cell cycle analysis.

CONCLUSIONS

These in vitro data support the concept that growth of meningioma cells may be modulated by cytokines, and they also indicate that recombinant OSM may be one future candidate for use in the adjuvant treatment of inoperable and recurrent meningiomas.

Familial meningioma: analysis of expression of neurofibromatosis 2 protein Merlin. Report of two cases

Meningiomas are primarily benign brain tumors thought to arise through multistep tumorigenesis, involving both the activation of oncogenes and the loss of tumor suppressor genes. The recently isolated neurofibromatosis 2 (NF2) tumor suppressor gene has been found to be mutated in a large proportion of meningiomas. Almost all cases of familial meningioma occur in association with NF2. Familial meningioma in isolation from NF2 (sporadic) is exceedingly rare, with only 14 reports since 1959. The authors report the existence of a family lacking any stigmata of NF2, in which two members had spinal meningiomas. Tumor specimens were subjected to immunocytochemical analysis for the NF2 protein product Merlin, which has been implicated in the tumorigenesis of meningioma. Merlin immunoreactivity was present in both tumor specimens, implying that the NF2 tumor suppressor gene was not deleted in these tumors. This supports the hypothesis that a second tumor suppressor gene locus, other than NF2, acts in the formation of familial sporadic meningioma. The results are discussed in the context of putative oncogenic mechanisms of familial meningiomas.

Immunohistochemical analysis of progesterone receptor and Ki-67 labeling index in astrocytic tumors

BACKGROUND

Intracranial tumors such as meningiomas express steroid hormone receptors but little is known regarding progesterone receptor (PR) in astrocytic tumors. The authors evaluated expression of PR in 86 astrocytic tumors in relation to tumor proliferative potential.

METHODS

Paraffin embedded tumor sections were stained with polyclonal antiprogesterone antibody by the peroxidase-antiperoxidase method and with monoclonal MIB-1-Ki-67 antibody by avidin-biotin complex immunohistochemistry.

RESULTS

Sixty-three of the 86 astrocytic tumors (73%) showed positive PR immunoreactivity. PR expression was observed in 4 of 9 pilocytic astrocytomas, 13 of 24 Grade 2 astrocytomas, 15 of 20 anaplastic astrocytomas, and 31 of 33 glioblastomas. In addition to the tumor cells, cells of microvascular endothelial proliferation and the smooth muscle of tumor vessel walls were frequently PR positive. Glioblastomas had a significantly higher percentage of PR positive cells compared with anaplastic (P < 0.0008) and low grade (P < 0.0001) astrocytomas. Patients with PR positive astrocytomas were of an older age than patients with PR negative astrocytomas (48.71 +/- 21.95 years vs. 37.09 +/- 24.69 years; P < 0.04). The mean Ki-67 labeling index (LI) was significantly higher in the high grade (3-4) astrocytomas compared with low grade (1-2) astrocytomas (P < 0.0001). PR positive astrocytic tumors had higher Ki-67 LI than PR negative tumors. PR expression was not correlated with tumor recurrence and patient survival.

CONCLUSIONS

The current study suggests that PR in the astrocytic tumors correlates with histologic grade and PR may participate in the growth of these tumors and tumor angiogenesis. The measurement of PR in these tumors may indirectly represent tumor growth potential.

Constitutive co-expression of estrogen and progesterone receptor mRNA in human meningiomas by RT-PCR and response of in vitro cell cultures to steroid hormones

Although it is well recognised that human meningiomas are rich in progesterone receptor (PgR), controversy has existed about the presence of the estrogen receptor (ER) in these tumours. We have investigated the presence of both ER and PgR in a series of 20 human meningiomas, spanning the main histological groups, using reverse transcription linked PCR (RT-PCR). Total RNA was extracted from whole tissues and reverse transcribed to yield cDNA. This was amplified using primers specifically designed to detect ER and PgR. All samples co-expressed ER and PgR mRNA, irrespective of tumour classification, patient age or sex. In general, transcripts for PgR appeared considerably stronger than those for ER, and although this was a purely qualitative study, it suggests increased expression of PgR. Addition of exogenous 17beta-estradiol or progesterone to meningioma cell cultures showed that 2/4 cultures responded to these steroids. Our results confirm that human meningiomas do express gene transcripts for ER, and that previous failures to detect ER in these tumours may be due to the lack of sensitivity of the techniques employed. However, these receptors may not be functional in all tumours.

Brain edema in meningiomas is associated with increased vascular endothelial growth factor expression

OBJECTIVE

Vascular permeability factor/vascular endothelial growth factor (VPF/VEGF), an endothelial cell-specific cytokine, induces proliferation of endothelial cells and increases vascular permeability dramatically. All gliomas secrete significant amounts of VEGF, whereas meningiomas are variable in expression. Thus, we sought to determine whether the extent of VPF/VEGF expression in meningiomas correlated with differences in brain edema associated with these tumors.

METHODS

Meningioma tissue samples from 37 patients (15 men, average age 65 +/- 13 yr; 22 women, average age 60 +/- 10 yr) who underwent surgery at or were referred to the University of Alabama Hospital were examined retrospectively for the extent of expression of immunoreactive VPF/VEGF. Additionally, peritumoral edema was assessed on a blinded basis radiographically from preoperative magnetic resonance imaging scans. Selected specimens were examined by in situ hybridization to document the source of VPF/VEGF.

RESULTS

The predominant meningioma subclassifications were transitional (57%) or meningothelial (27%) subtypes. VPF/VEGF immunoreactivity ranged from 0 to 3.5, with a median value of 2 on a subjective 5-point scale; magnetic resonance imaging-assessed edema ranged in extent from 0 to 4 (subjective 5-point scale), with a median value of 2.5. The correlation of determination (R2) of magnetic resonance imaging-assessed tumor edema rating and VPF/VEGF staining intensity rating was 0.6087 (r = 0.78; P = 0.0001). In situ hybridization localized VPF/VEGF messenger ribonucleic acid in meningioma cells and not in normal parenchymal brain cells.

CONCLUSION

These data suggest that meningioma-associated edema may be a result of the capacity of meningioma cells to produce VPF/VEGF locally, leading to increased tumor neovascularization and enhanced vascular permeability.

Formation of autocrine loops in human cerebral meningioma tissue by leukemia inhibitor factor, interleukin-6, and oncostatin M: inhibition of meningioma cell growth in vitro by recombinant oncostatin M

It has been demonstrated that growth of cerebral meningiomas found in humans is controlled by a variety of factors, including growth factors, aminergic agents, neuropeptides, and steroids. The authors investigated the presence and function of the cytokines leukemia inhibitory factor (LIF), interleukin-6 (IL-6), and oncostatin M (OSM) on meningioma cell proliferation.

Active transcription of LIF, IL-6, OSM, their related receptors (LIF-R, IL-6-R, gp130), and the consecutive signal-transducing molecules (STAT 1, STAT 3, and STAT 5a) were analyzed in reverse transcriptase-polymerase chain reaction experiments.

The presence of endogenous LIF, IL-6, and OSM proteins was demonstrated in the supernatant of cultured meningioma cells using enzyme-linked immunosorbent assay and Western blot experiments, thus indicating an autocrine signaling pathway for all three cytokines.

The biological function of all three cytokines was evaluated by studying their effects on meningioma cell growth. Recombinant LIF and IL-6 showed no significant growth modulating effects; however, recombinant OSM decreased meningioma cell growth by 66%. The antiproliferative potency of OSM was demonstrated by cell count experiments, [3H]thymidine incorporation assay, and cell cycle analysis. These in vitro data support the concept that growth of meningioma cells may be modulated by cytokines and also indicates that recombinant OSM may be one of the future candidates for use in the adjuvant treatment of inoperable and recurrent meningiomas.

Progesterone and estrogen receptors in meningiomas: prognostic considerations

Meningiomas often contain steroid hormone receptors, but the correlation of receptor presence with patient outcome or mitotic index is unclear. Intracranial meningiomas from 70 patients (27 males and 43 females, mean age 52.9 + 1.7 years [mean +/- standard error of the mean], range 15-78 years) were evaluated immunocytochemically for female sex hormone receptors using specific monoclonal antibodies. Prognostic correlations were determined using statistical analyses that included clinical and histological variables. Twenty-eight tumors were benign, 27 had atypical features, and 15 were malignant. Thirty tumors were meningotheliomatous, 11 were fibroblastic, 28 were transitional, and one was secretory. Twenty-nine of the 70 primary tumors recurred (mean interval to recurrence 50.1 +/- 10 months). The mean progression-free follow-up period for patients without recurrence was 82.1 +/- 7.7 months. Nuclear staining for the progesterone receptor (PR) was found in 58 cases (83%) and PR status was scored as 0 (0% nuclei positive), 1 (< 1%), 2 (1-9%), 3 (10-49%), or 4 (> 50%). Only six tumors (8.6%) contained nuclear estrogen receptor (ER) staining, which was limited to a small number of nuclei (< 1%). Fisher's exact test (two-tailed) showed an inverse correlation between tumor grade and PR staining score (p < or = 0.001), with 96% of benign and 40% of malignant meningiomas containing PR-positive nuclei. No correlation between age or histological subtype and PR score was detected. Meningiomas from female patients had more PRs (p < or = 0.05). Analysis of variance revealed that the mitotic index (total counts of mitoses per 10 high-power fields) for tumors with 0 PR staining (18 +/- 4.4) was higher (p < or = 0.0001) than for those with PR scores of 1 to 4 (4.3 +/- 1.9, 5.1 +/- 2, 2.2 +/- 0.8, and 1.7 +/- 0.9, respectively). Univariate analysis indicated that the absence of PR, high mitotic index, and higher tumor grade were significant factors for shorter disease-free intervals. Multivariate analysis showed that a three-factor interaction model, with a PR score of 0, mitotic index greater than 6, and malignant tumor grade, was a highly significant predictor (p < or = 0.0001) for worse outcome in patients harboring meningiomas. These data indicate that the presence of PRs, even in a small number of tumor cells, is a favorable prognostic factor for meningiomas.

Epidemiology and etiology of intracranial meningiomas: a review

The frequency of meningiomas has been the topic of relatively few reports. Hospital-based brain tumor series indicate that the incidence is approximately 20% of all intracranial tumors; population-based studies indicate an overall incidence of 2.3/100,000. Although intracranial tumors as a whole show a higher prevalence in males than in females, meningiomas have a 2:1 female-to-male ratio. Between Caucasians and Africans, African-Americans, and Asians, certain differences also have been noted. Meningiomas in children are rare and differ from those in adults and other childhood tumors; they are even more rare in infants. Several features indicating etiologic factors have been identified, among which are ionizing radiation, head injury, hormones, and other receptor binding sites, genetic factors, and viruses. The most common source of exposure of the head to ionizing radiation is dental radiographic examination. Since 1922, head trauma has been considered a possible risk factor, but recent large studies do not support this link. Several factors have prompted studies of estrogens and progestogens as risk factors for meningiomas. Other studies have sought to determine if certain individuals have an inherited predisposition for developing a meningioma and/or if viruses, which may act alone or with other mutagens, figure into the formation of a meningioma. The most promising studies are those of cytogenetics, and future elucidation of factors associated with the loss of one copy of chromosome 22, another phenomenon that has been identified in meningiomas, may lead to screening tests and gene therapy.

The biology of meningiomas

Meningiomas, long neglected as a subject for biological studies, are now being examined more widely as their potential for clinical recurrence and malignancy has been recognized. Most laboratory studies have focused on descriptive analyses of the content of various molecules in ex vivo specimens removed at surgery. Perturbative experiments using cultured cells are possible, but they are complicated by senescence of the cells. The respective importance of the sex steroids (estrogen, progesterone, and androgens), classical growth factors, angiogenic factors, and proteolytic enzymes in the biological behavior of meningiomas is now apparent and is coming under more detailed scrutiny. As general theories of neoplasia crystallize in other systems, the ability of meningiomas to proliferate, invade, and provoke neovascularization will be better understood.

Immunohistochemical detection of progesterone receptors and the correlation with Ki-67 labeling indices in paraffin-embedded sections of meningiomas

Female sex steroids may play a role in the proliferation of meningiomas. We investigated the progesterone receptor (PgR) immunoreactivities and the Ki-67 labeling indices in the formalin-fixed, paraffin-embedded sections of meningiomas from 39 patients. After autoclave pretreatment of the sections (which were immersed in a citrate buffer), the sections were incubated with the monoclonal antibody for the PgR and the MIB-1 monoclonal antibody for the Ki-67 antigen. In the meningiomas studied, the immunoreactivity for the PgR was moderately to strongly positive in 51%, weakly positive in 21%, and negative in 28%. The nuclear staining for the PgR was clear, and no tumors were positive for the estrogen receptor. The Ki-67 labeling indices of the PgR-positive meningiomas (mean +/- standard deviation, 2.35 +/- 2.12%) were significantly lower than those of the PgR-negative meningiomas (6.53 +/- 4.83%) (P < 0.05). Two meningiomas that had recurred more than once showed high Ki-67 labeling indices and negative immunostaining for the PgR. These findings indicate that the PgR status may be closely related to the growth potentials of the meningiomas. Our results confirm that the immunodetection of the PgR and the Ki-67 antigen on the paraffin sections of meningiomas provides a practical tool for estimating the biological behavior of the meningiomas.

Meningioma In Congenital Adrenal Hyperplasia

A diversity of malignancies have been reported in patients with congenital adrenal hyperplasia. We report a case of multiple meningiomas, tumors which are more common in females and reported to have sex steroid receptors, in a 46,XX male (severe female hermaphrodite raised as a male) with 21-hydroxylase deficiency. The patient has been treated with glucocorticoids since 3 years of age and testosterone since puberty.

Androgen receptor expression in meningiomas

The predominance of meningiomas in females, the accelerated growth of these tumors during the luteal phase of the menstrual cycle and during pregnancy, and the association between meningiomas and breast cancer have led to a number of studies examining the potential role of steroids in the growth of meningiomas. The possibility that androgens play a role in meningioma proliferation has been suggested by a small number of investigators. The aim of this study was to examine the expression of androgen receptor messenger ribonucleic acid (mRNA) and correlate it using immunochemistry with the nuclear localization of androgen receptor in a large number of meningiomas. Thirty-nine meningiomas were examined by Northern blot analysis for the presence of measurable amounts of androgen receptor mRNA and eight of these were analyzed by immunohistochemistry for receptor protein. Sixty-seven percent of the meningiomas expressed androgen receptor mRNA. There was a marked predominance of women among the patients whose tumors expressed androgen receptor; 69% were women and 31% were men. The immunohistochemical data correlated with Northern blot analysis of mRNA. The staining was predominantly nuclear, suggesting that the androgen receptor resides in a location that can activate gene expression.