Estrogen and progesterone receptors in acoustic neuromas

Large vestibular schwannomas presenting in the late state of pregnancy: a case report and literature review

Vestibular schwannomas in pregnancy have rarely been reported, and there is a lack of in-depth discussion on the experience of management of massive acoustic neuromas in pregnancy. Herein, we present a pregnant woman with a giant vestibular schwannoma and obstructive hydrocephalus who presented at 30 weeks of gestation. She was initially misdiagnosed as having a pregnancy-related reaction of headache, dizziness, and vomiting that had occurred 2 months earlier. After observation at home, her symptoms progressed at 30 weeks of gestation, and imaging findings revealed a brain tumor in the CPA region with secondary cerebella tonsil herniation and obstructive hydrocephalus, and she was transferred to our center for treatment. Consequently, we relieved her hydrocephalus with a ventriculoperitoneal shunt (V-P shunt) and used corticosteroids to simulate fetal maturation. After 10 days, her mental condition deteriorated, and her right limb muscle strength gradually decreased until grade 0 (MMT Grading). Finally, under a joint consultation with the Department of Neurosurgery, Obstetrics, and Anesthesiology, she underwent a cesarean section under general anesthesia and first-stage tumor removal at 31 weeks of gestation. Upon discharge, the previously observed neurological deficits, which were reversible and had manifested during her gestational period, had been successfully resolved, and the fetus had been conserved. The neuroimaging confirmed the complete tumor removal, while the neuropathologic examination revealed a vestibular schwannoma. Therefore, we recommend early diagnosis and treatment for these patients, especially people with headaches, vomiting, and sudden hearing loss during pregnancy. Herein, we concluded that our cases provide a valuable experience in the latest acceptable time frame for the operation to prevent irreversible neurological impairment and premature delivery in late pregnancy.

Tumor Microenvironment in Sporadic Vestibular Schwannoma: A Systematic, Narrative Review

Although diagnosis and treatment of vestibular schwannomas (VSs) improved in recent years, no factors have yet been identified as being capable of predicting tumor growth. Molecular rearrangements occur in neoplasms before any macroscopic morphological changes become visible, and the former are the underlying cause of disease behavior. Tumor microenvironment (TME) encompasses cellular and non-cellular elements interacting together, resulting in a complex and dynamic key of tumorigenesis, drug response, and treatment outcome. The aim of this systematic, narrative review was to assess the level of knowledge on TME implicated in the biology, behavior, and prognosis of sporadic VSs. A search (updated to November 2022) was run in Scopus, PubMed, and Web of Science electronic databases according to the PRISMA guidelines, retrieving 624 titles. After full-text evaluation and application of inclusion/exclusion criteria, 37 articles were included. VS microenvironment is determined by the interplay of a dynamic ecosystem of stromal and immune cells which produce and remodel extracellular matrix, vascular networks, and promote tumor growth. However, evidence is still conflicting. Further studies will enhance our understanding of VS biology by investigating TME-related biomarkers able to predict tumor growth and recognize immunological and molecular factors that could be potential therapeutic targets for medical treatment.

Immunohistochemical Expression of Progesterone Receptors in Nonmeningothelial Central Nervous System Tumors

INTRODUCTION

Immunostaining of progesterone receptors (PRs) has been described as a prognostic factor related to recurrences in meningiomas. However, its expression in other primary intracranial tumors has been poorly studied. In this paper, we compare the pattern of expression of the receptor in meningiomas with that of nonmeningothelial intracranial tumors to evaluate its value in the diagnosis of the former.

MATERIALS AND METHODS

A total of 42 nonmeningothelial intracranial tumors (21 glioblastomas, 4 anaplastic oligodendrogliomas, 4 oligodendrogliomas, 1 pilomyxoid astrocytoma, 3 ependymomas, 8 schwannomas, 1 chordoid chordoma) and 32 meningiomas (1 rhabdoid, 1 papillary, 5 atypical, 7 with histologic features of more aggressive behavior, 1 microcyst, 8 meningothelial, 7 transitional, 2 fibroblastic) were studied for PR by immunohistochemistry.

RESULTS

About 73.8% of the nonmeningothelial tumors and 100% of the meningiomas were positive for the receptor, the difference being statistically significant (P=0.0017). The mean percentage of positive tumor cells per high-power field was frequently higher than 30% in meningiomas and lower than 10% in nonmeningothelial tumors (P=0.0001).

CONCLUSIONS

Although we detected that immunostaining for the PR is more frequently observed in meningiomas, we confirmed its expression in diverse nonmeningothelial primary intracranial tumors. Immunohistochemistry for PR would be useful in the diagnosis of meningioma only when its positivity shows a mean higher than 30% of the positive tumor cells per high-power field.

Immunohistochemical investigation of hormone receptors and vascular endothelial growth factor concentration in vestibular schwannoma

OBJECTIVES

To determine if a relationship exists between the presence of estrogen receptors (ER), progesterone receptors (PR), or vascular endothelial growth factor (VEGF) and the size, growth rate, and behavior of vestibular schwannoma tumors.

DESIGN

Nine tumor samples from young female patients with large vestibular schwannoma tumors were preselected because they were presumed to be faster growing, more aggressive tumors. Immunohistochemical staining was performed using monoclonal mouse antibodies to ER, PR, and VEGF.

RESULTS

The mean age of the study sample was 32.3 years, mean tumor size was 3.2 cm, and the average growth rate was 0.4 cm per 2 months. The results of immunohistochemical staining for ER and PR in all nine samples were unequivocally negative. Eight of nine tumor samples stained positive for VEGF, with five demonstrating low intensity and three demonstrating moderate intensity staining.

CONCLUSIONS

There is histopathological evidence for the expression of VEGF in vestibular schwannomas but not for ER and PR. Further studies are necessary to determine the role of VEGF and other molecular pathways in the growth of vestibular schwannomas and the application of anti-VEGF therapy as a potential treatment option in the future.

Estrogen receptor expression in sporadic vestibular schwannomas

HYPOTHESIS

We hypothesize that vestibular schwannomas (VSs) exhibit up-regulation of estrogen receptor (ER) at the protein level compared with control great auricular nerve (GAN).

BACKGROUND

It has been reported in the literature that VS occur more commonly in women and tend to be larger and more vascular in women, and growth rate can accelerate during pregnancy. The literature contains widely divergent results on ER expression in VS, however, varying from no detectable levels to detection of ER in all samples.

METHODS

Sixteen sporadic VS specimens were immediately snap-frozen after microsurgical excision and analyzed for phosphorylated and total levels of ERα with Western blot analysis. ERα expression levels were normalized to actin; then, relative expression to GAN was determined.

RESULTS

All VS specimens exhibited expression of both phosphorylated and total ERα. Total ERα expression in VS is equivalent to or slightly up-regulated compared with GAN. VS specimens exhibited more pronounced up-regulation of phosphorylated (i.e., activated) levels of ERα compared with GAN.

CONCLUSION

We have demonstrated that ERα expression in VS is equivalent to GAN. The phosphorylated form of the receptor is up-regulated compared with GAN, however, indicating a higher level of ERα activation in sporadic VS compared with normal nerve. Further investigation into antiestrogen therapy for VS is warranted.

Molecular biology of familial and sporadic vestibular schwannomas: implications for novel therapeutics

Vestibular schwannomas (VSs) are benign tumors arising from the sheath of cranial nerve VIII. The pathogenesis underlying most familial and sporadic VSs has been linked to a mutation in a single gene, the neurofibromin 2 (NF2) gene located on chromosome 22, band q11-13.1. In this review, the authors summarized what is known about the epidemiology of NF2 mutations and patients with VSs. The authors also discuss the function of the NF2 gene product, merlin, and describe the known and hypothetical effects of genetic mutations that lead to merlin dysfunction on a broad variety of cellular and histological end points. A better understanding of the molecular pathobiology of VSs may lead to novel therapeutics to augment current modalities of treatment while minimizing morbidity.

Expression of estrogen and progesterone receptors in vestibular schwannomas and their clinical significance

Objective

The objective was to determine the expression of estrogen and progesterone receptors in vestibular schwannomas as well as to determine predictive factors for estrogen and progesterone receptor positivity.

Materials and methods

The study included 100 cases of vestibular schwannomas operated from January 2006 to June 2009. The clinical details were noted from the medical case files. Formaldehyde-fixed parafiin-embedded archival vestibular schwannomas specimens were used for the immunohistochemical assessment of estrogen and progesterone receptors.

Results

Neither estrogen nor progesterone receptors could be detected in any of our cases by means of well known immunohistochemical method using well documented monoclonal antibodies. In the control specimens, a strongly positive reaction could be seen.

Conclusion

No estrogen and progesterone receptor could be found in any of our 100 cases of vestibular schwannomas. Hence our study does not support a causative role of estrogen and progesterone in the growth of vestibular schwannoma as well as hormonal manipulation in the treatment of this tumor.

Vestibular schwannoma quantitative polymerase chain reaction expression of estrogen and progesterone receptors

OBJECTIVES/HYPOTHESIS

Determine the role of estrogen receptor (ER) and progesterone receptor (PR) expression in sporadic and neurofibromatosis 2 (NF2)-related vestibular schwannomas (VS). Growth and proliferation signaling in human VS tumorigenesis may play a key role in molecular therapeutic targeting. VS carry mutations of the NF2 gene encoding the tumor suppressor, merlin, which interacts with ErbB2 in Schwann cells, implicating ErbB receptors in VS tumorigenesis. ErbB receptor family members are overexpressed or constitutively activated in many human tumors, and are effective therapeutic targets in some human cancers. VS occur more frequently in women and are larger, more vascular, and demonstrate increased growth rates during pregnancy. ER and PR may play a role in ErbB pathway activation and VS progression.

STUDY DESIGN

Quantitative real-time polymerase chain reaction (qRT-PCR) for ER and PR messenger RNA was performed using greater auricular and vestibular nerve controls (n = 8), sporadic VS (n = 23), and NF2-related VS (n = 16) tissues.

METHODS

The qRT-PCR data were normalized with standardization to a single constitutively expressed control gene, human cyclophylin.

RESULTS

Reverse transcription of messenger RNA from control and tumor specimens followed by RT Q-PCR demonstrated differences in ER and PR gene expression between sporadic and NF2-related VS.

CONCLUSIONS

ER and PR expression in VS might have implications for development of a VS-specific drug delivery system using antihormone and ErbB pathway small molecule inhibitors, due to crosstalk between these receptors. These signals may be critical for re-establishing ErbB-mediated cell density dependent growth inhibition.

Expression and clinical significance of Ki-67, oestrogen and progesterone receptors in acoustic neuroma

Objective:

The objective was to assess the presence of Ki-67, and oestrogen and progesterone hormone receptors as well as their clinical correlates in acoustic neuroma.

Methods:

Medical records of 59 patients who were operated on for acoustic neuroma between 1995 and 2003 were evaluated retrospectively. Formaldehyde-fixed paraffin-embedded archival acoustic neuroma specimens of the patients were used for immunohistochemical assessments of oestrogen and progesterone hormone receptors, and Ki-67 proliferative marker.

Results:

Tumour sizes were small (<19 mm), medium (20–39 mm) and large (>40 mm) in 21, 35 and 3 patients, respectively. On immunohistochemistry, all samples were (+) for progesterone receptor and (–) for oestrogen receptor staining. Ki-67 staining was encountered in 34 of 59 (57.6 per cent) patients, and Ki-67 values ranged from 0 per cent to 10.9 per cent (mean 1.36 per cent). There was no correlation between Ki-67, gender, tumour size and symptoms of the patients (p > 0.05).

Conclusion:

Oestrogen is not an important hormone in acoustic neuroma due to the absence of oestrogen receptor expression in the tissue samples. Since the progesterone receptor is expressed in all acoustic neuroma samples, further studies are necessary to find out about the inhibitory effect of antiprogesterone treatment on acoustic neuroma growth, which may be important particularly in elderly people or high-risk patients. Although Ki-67 is expressed in the majority of acoustic neuromas, it is not an important marker in clinical practice due to a lack of any correlation with the clinical parameters.

Immunohistochemical Demonstration of Vascular Endothelial Growth Factor in Vestibular Schwannomas Correlates to Tumor Growth Rate

OBJECTIVE

Vascular endothelial growth factor (VEGF) is one of the most potent mediators of angiogenesis, which is a mandatory process during tumor growth. The present objectives were to determine expression of VEGF in vestibular schwannomas by immunohistochemistry and to examine a possible correlation with symptom duration, tumor size, or growth rate.

STUDY DESIGN

Retrospective patient file review; immunohistochemistry and light microscopy of vestibular schwannomas removed by surgery.

METHODS

Vestibular schwannomas from 18 patients were immunolabelled using a polyclonal antibody against VEGF, followed by light microscopy and blinded semiquantitation of VEGF expression. Fifteen patients had a well-defined tumor growth rate defined by repeated preoperative magnetic resonance imaging scans.

RESULTS

All tumors showed expression of VEGF in the Schwann cell cytoplasm, with a more intense staining of the perinuclear region of some cells. The staining intensity varied from tumor to tumor, and semiquantitation revealed a significant correlation between VEGF expression and tumor growth rate, but not symptom duration or tumor size.

CONCLUSION

VEGF is expressed in vestibular schwannomas and the level of expression correlates positively with tumor growth rate, but not with tumor size and symptom duration. We conclude that VEGF seems to be a factor involved in the growth of vestibular schwannomas.

Determinants of tumor size and growth in vestibular schwannomas

OBJECT

This study was undertaken to analyze factors associated with the size of unilateral vestibular schwannomas (VSs).

METHODS

A retrospective analysis of an unselected and sequential series of 433 patients with unilateral VSs was conducted. Tumor size was defined by the largest dimension of the tumor in the cerebellopontine angle, and the size was tested for a relationship with patient age and sex. In a subgroup of 231 patients in whom data were available, tumor size was also tested for a relationship with tumor cysts or the absence of an internal auditory canal (IAC) component. Some patients underwent a period of surveillance with serial imaging studies to monitor for tumor growth. Data from these patients, excluding those with cystic tumors, were analyzed to see if tumor growth was related to patient age, sex, or tumor size. CONCLUSIONS; Larger tumors were found in younger patients, in females, in the subgroup of cystic tumors, and in patients in whom there was no tumor component in the IAC. The probable explanations for these larger tumors are a faster growth rate and/or a delay in symptom onset. When untreated tumors are managed with observation, measurable growth is more often seen in larger tumors, although smaller tumors have a faster relative growth rate than larger ones.

Clinicopathologic growth factors in vestibular schwannomas: a morphological and immunohistochemical study of 69 tumours

Tumour growth of vestibular schwannomas is still difficult to predict. The aim of our study was to determine whether any defined histopathological feature was correlated with the clinical course. We did a retrospective study with 69 paraffin-embedded tumours to establish whether the number of vessels, blood cells extravasation or degree of inflammation, all semi-quantitatively assessed, could be indicative of potential of growth. An immunohistochemical study was also performed with an endothelial marker CD34, the leukocyte common antigen CD45 and the estrogen and progesterone hormone receptors. All these parameters were correlated with patient's age, duration of symptoms (d), with a clinical growth index (CLI = tumour size/d). No clinical parameters proved to be predictive of tumour growth. Tumour size was significantly (p = 0.01) related to the number of vessels and we found a significant relationship between the clinical growth index (CLI) and total number of vessels, especially when duration of symptoms lasted less than 1 year (p < 0.001). However, we found no relationship between duration of symptoms or CLI and CD34 index. The degree of inflammation was significantly correlated (p = 0.007) with duration of symptoms when it lasted more than 1 year. The CD45 index and the semi-quantitative evaluation of the inflammation were well correlated (p = 0.001). No estrogen receptors antigenic site was detected and only seven tumours expressed progesterone receptor in a few cells without any significant clinical value. These results suggest that vessel density is determinant for sporadic acoustic neuroma growth especially for a short clinical course.

Effects of estrogen and tamoxifen on growth of human vestibular schwannomas in the nude mouse

Vestibular schwannomas have been noted to have increased frequency and aggressivity in female patients, suggesting a possible role of estrogen. This study evaluated the effects of estrogen and tamoxifen on the growth of human vestibular schwannoma tissue implanted in subcutaneous pockets of nude mice. Animals were implanted with 1 of 3 human vestibular schwannomas and observed for 28 days. Mice were then separated into 3 treatment groups: controls, estrogen (receiving 1.7 mg of 17B-estradiol), and estrogen + tamoxifen (receiving 1.7 mg of 17B-estradiol + 10 mg of tamoxifen), and treated for 28 days. Mice treated with estrogen showed increased growth that was statistically significant (P < 0.05) when compared with that of both the controls and the animals treated with estrogen + tamoxifen. Controls and animals treated with estrogen + tamoxifen showed a general trend of decreased volume during the treatment period. These early results support the hypothesis that estrogen modulates the growth of vestibular schwannomas in the nude mouse model and that these effects can be blocked by tamoxifen administration.

Hormone receptors in vestibular schwannomas

The possibility that steroid hormones play a role in vestibular schwannoma proliferation has been suggested by a number of investigators. There is conflicting information about the presence of steroid hormone receptors in these tumors. The aim of this study was to examine the expression of androgen, progesterone, glucocorticoid and estrogen receptor messenger ribonucleic acid levels (mRNA) in twenty-one vestibular schwannomas by either Northern blot analysis or the polymerase chain reaction (PCR). Glucocorticoid receptor mRNA was expressed in all twenty-one tumors examined. Only two male specimens were positive for androgen receptor mRNA expression by PCR-Southern blot analysis. Thirty-three percent of the schwannomas (7/21) showed a strong band for progesterone receptor mRNA by PCR-Southern blot analysis; there were an equal number of males and females in this group. Estrogen receptor mRNA levels were undetectable in all tumors examined by PCR-Southern blot analysis. These studies suggest that the pattern of steroid receptor expression is different in schwannomas than in meningiomas. Individual vestibular schwannomas need to be examined for their steroid receptor mRNA expression mRNA expression to know whether they will be responsive.

Different aspects of hearing preservation in surgery of vestibular schwannoma in women and men

Pre-operative and postoperative auditory function was reviewed retrospectively in 98 patients with vestibular schwannomas. According to their hormonal status, women were categorized as "premenopausal" and "postmenopausal". Before surgery, 48% of the women (65% premenopausal) and 16% of the men presented with sudden hearing loss. The degree of auditory function before operation was similar for women and men. Preservation of pre-operative hearing was possible for 41% of the women (21% premenopausal) and 59% of the men. Further details of the surgery and the results of histopathological examination were also compared for women and men. Our results support substantial evidence that hearing preservation after surgery of vestibular schwannoma is easier to accomplish for men than for women. The finding of significantly more sudden hearing loss in premenopausal women may suggest a hormonal influence on tumour growth, which may also be partially responsible for the difference in hearing prognosis between women and men.

Angiogenesis from the eighth cranial nerve to vestibular schwannomas

Vascularization between vestibular schwannomas and the adjacent eighth cranial nerve was examined in order to elucidate the angiogenic effect of these tumours. Specimens from 12 patients were examined by light microscopy and immunohistochemistry (series 1), while specimens from another 17 patients were examined by light and transmission electron microscopy (series 2). Slight to marked angiogenesis was found in 5 patients from series 1 and 7 patients from series 2. Ultrastructural examination indicated that these blood vessels were more fragile than those in the normal eighth cranial nerve. These findings suggested that sudden hearing loss in vestibular schwannoma patients may be related to the disruption of such blood vessels. In addition, surgical injury to these blood vessels may cause postoperative hearing loss despite preservation of the cochlear nerve.

Expression of steroid receptors in acoustic neuroma

The expression of steroid receptors has been investigated in an attempt to clarify the role of steroid hormones in the proliferation and progression of acoustic neuromas. Specimens of tumours taken during translabyrinthine surgery were tested for cytosolic (c) and nuclear (n) steroid receptors. Oestrogen and progesterone receptor levels were evaluated by enzymatic immuno-assay, while androgen receptor binding levels were detected by dextran-coated charcoal method in a single-step determination. In some cases, the six point Scatchard analysis of cytosolic and nuclear androgen receptor was also performed. Threshold values were: 3 fmol/mg of proteins for cytosolic steroid receptors and 20 fmol/mg DNA for nuclear steroids, which corresponded to approximate median values of cytosolic and nuclear oestrogen and progesterone, respectively. Oestrogen and progesterone appeared to be localized more frequently in the nuclei rather than in the cytosol (70% oestrogen and progesterone positivity in the nuclei; 30% oestrogen, 40% progesterone positivity in the cytosol), while androgen receptors were preferentially localized in the cytosol (80% positivity in the cytosol; 40% positivity in the nuclei). A negative non-linear correlation between cytosolic oestrogen and cytosolic androgen receptors was found. There was a direct linear correlation between cytosolic oestrogen and nuclear oestrogen levels. A strict correlation between nuclear oestrogen and nuclear progesterone incidence was shown. Preliminary analysis of clinical data and biochemical parameters showed that cytosolic progesterone levels inversely correlated with tumour size.

Acoustic schwannoma and pregnancy: a DNA flow cytometric, steroid hormone receptor, and proliferation marker study

For a long time, it has been speculated that pregnancy stimulates the growth of acoustic schwannomas. To test this hypothesis, immunohistochemical stains for estrogen receptor, progesterone receptor, and proliferating cell nuclear antigen (PCNA) were performed. Flow cytometric studies for DNA ploidy and S-phase fraction determinations were also performed. The study subjects included 6 female patients with unilateral acoustic tumors; at the time of tumor removal, 1 woman was pregnant and the other 5 women were 2 to 10 months postpartum. The age-sex-matched control group consisted of 6 men and 12 nonpregnant women, all with acoustic schwannomas similar in size to those of the study group. The study found no statistically significant association between the presence or quantity of estrogen or progesterone receptors and pregnancy, DNA ploidy, proliferation indices, or clinical data. Based on PCNA indices, large tumors tended to be less "biologically active" than small lesions (P < .01). The authors concluded that pregnancy does not significantly stimulate the cellular growth of acoustic schwannomas.

Acoustic Neuroma (Vestibular Schwannoma): Growth and Surgical and Nonsurgical Consequences of the Wait-And-See Policy

A prospective study of the consequences of the wait-and-see policy in patients with neuroradiologic diagnostic evidence of having vestibular schwannoma was conducted in a series of 123 patients (127 tumors) over a 20-year period, from 1973 to 1993. The mean follow-up period was 3.4 years, mean annual growth rate was 3.2 mm/year, mean annual volume growth rate was 0.72 ml/year, and mean annual relative growth rate was 41%. Tumor growth was observed in 90 (74%) patients (94 tumors), no growth was seen in 23 (18%) patients (23 tumors), and negative tumor growth was seen in 10 (8%) patients (10 tumors). Surgery due to tumor growth was performed in 35 (28%) patients (35 tumors), 7 (6%) patients (7 tumors) were treated with γ-radiation and/or shunt insertion, 7 (6%) patients died of brain stem herniation induced by tumor compression, 9 (7%) patients died of non-tumor-related causes, 28 patients were classified as candidates for hearing preservation surgery, and 21 (75%) patients lost their candidacy during the observation period due to tumor growth and/or deterioration of hearing. The results may limit indications for allocation of patients with vestibular schwannoma to the wait-and-see group.

Acoustic neuroma. Follow-up of 78 patients

This study assesses the outcome in 78 patients who had been diagnosed with acoustic neuroma over a period of 13 years. Forty-six patients were treated with translabyrinthine surgery, 13 with suboccipital surgery and/or ventricular drainage, and 19 patients (20 neuromas) were kept under observation. Of the 59 patients who had surgery, four died, 30 had problems with eating, drinking and balance, 17 had severe facial palsy, 21 discontinued their work after the operation and 30 had psychological problems. Twenty neuromas have not been operated upon and the patients have not deteriorated medically or socially. It is concluded that acoustic neuroma is a serious disease and that a conservative policy (wait and scan) is preferable in elderly patients.

Epidemiology and clinical features of vestibular schwannoma in Manitoba, Canada

The incidence of vestibular schwannoma (acoustic neuroma) in Manitoba, Canada was reviewed. From 1987 through 1991, 71 tumors were diagnosed in 69 patients. The overall annual incidence rate for both sexes was 1.27/100,000 with male and female annual incidences of 1.31/100,000 and 1.24/100,000 respectively. For males, there was an early peak in the age group 30-39 years (2.1/100,000). Following the fifth decade, the incidence for males plateaued (2.7-3.6/100,000). For females, the incidence increased with age up to age 60-69 years (4.1/100,000). This was followed by a progressive decline in the incidence. Although the incidence of vestibular schwannoma was relatively high, the clinical features were not unlike those previously reported in the literature.