Oestrogen and progesterone receptors in acoustic neuroma

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.

Residual tumour after vestibular schwannoma surgery

OBJECTIVE

To evaluate residual tumour occurrence after vestibular schwannoma surgery, based on intra-operative registration and magnetic resonance imaging one year post-operatively.

METHODS

Patients undergoing translabyrinthine surgery for vestibular schwannoma in Denmark between 1976 and 2008 were registered in a national database covering 5.5 million inhabitants.

RESULTS

Translabyrinthine surgery was undertaken on 1143 patients. Of these, 978 had total, 140 near-total and 25 subtotal tumour excision, as assessed intra-operatively by the surgeon. One year after surgery, 65 per cent of small tumour remnants and 11 per cent of large tumour remnants were not visible on magnetic resonance imaging. The mean pre-operative size was significantly smaller for totally excised tumours, compared with near-totally and subtotally excised tumours. Revision surgery was performed for 14 patients (1.2 per cent), of whom 2 had received total, 5 near-total and 6 subtotal excisions initially.

CONCLUSION

Most residual tumours disappear spontaneously, probably due to devascularisation. Few patients with a small residual vestibular schwannoma will require revision surgery or secondary radiotherapy.

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.

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.

Revision surgery for residual or recurrent vestibular schwannoma

OBJECTIVE

Assess the requirement for and describe the complication rates of revision surgery for vestibular schwannoma.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Patients undergoing surgery for vestibular schwannoma by the Manchester Neurotology Service between 1978 and 2004.

INTERVENTION

Surgery.

MAIN OUTCOME MEASURE(S)

The presence of recurrent or residual tumor; necessity for further treatment; complications from revision surgery.

RESULTS

Primary surgery was undertaken on 1,037 tumors, with 866 total (19 recurred), 128 near-total, and 43 subtotal removals. Further treatment was performed for 4 recurrent, 2 near-total, and 11 subtotal excised tumors. Thirty-five revision operations resulted in 14 total (1 recurred), 8 near-total, and 13 subtotal removals. Further treatment was required for 3 near-total and 6 subtotal excisions. Poor preoperative facial function (House-Brackmann Grades 4-6) was present in 9 of the 35 patients. A further 10 deteriorated by at least 3 grades by 1 year postoperatively. Other complications of revision surgery included 3 patients with cerebrospinal fluid leaks, a postoperative hematoma requiring evacuation, 2 cerebrovascular accidents, and 2 patients with new cranial nerve deficits.

CONCLUSION

Most residual tumors after primary surgery are successfully managed with watch and rescan. Tumor fragment size is the greatest determinant of revision treatment. After revision surgery, tumor regrowth is much less predictable. Revision surgery is usually considerably more difficult than primary surgery, with a higher complication rate, particularly with regard to the facial nerve. Changing the approach for revision surgery may confer an advantage to facial nerve function.

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.

Vestibular schwannomas in children

OBJECTIVE

This article highlights the clinical presentation and management issues of unilateral vestibular schwannomas in children. We demonstrate how the presentation differs from neurofibromatosis type 2 (NF2) and from adult unilateral vestibular schwannomas.

STUDY DESIGN

This article is composed of a series of three cases and a literature review.

SETTING

The study was performed at a university hospital (tertiary referral center).

PATIENTS

Three children, aged 9, 11, and 13 years, with histologically confirmed vestibular schwannomas were studied. All children under 16 years of age in the world literature with unilateral vestibular schwannomas were reviewed.

INTERVENTION

Analysis of presentation and surgical management of these three children and those children reported in the literature.

MAIN OUTCOME MEASURE

Pattern of presentation relative to children with NF2 and people with adult unilateral vestibular schwannomas.

RESULTS

Two patients had multiple cranial nerve weakness and recurrence, and one patient had successful removal of the tumor with preservation of all functions of the cranial nerves, including the facial nerve.

CONCLUSION

Vestibular schwannomas in children are very uncommon. It is likely that it is the first manifestation of NF2, but it may also be a variant of sporadic vestibular schwannomas. A presentation of three cases and a review of 36 other cases in the literature demonstrates how the presentation is different from adult sporadic vestibular schwannomas and NF2 because it lacks primary audiological symptoms. The study also provides evidence of non-NF2 vestibular schwannomas presenting in children and suggests that it is likely that these are a variant of unilateral sporadic vestibular schwannomas. The search for the features of NF2 in these cases remains mandatory.

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.

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.

Variation of expression of the gene for type 2 neurofibromatosis: absence of a gender effect on vestibular schwannomas, but confirmation of a preponderance of meningiomas in females

Type 2 neurofibromatosis is a dominantly inherited disorder in which the great majority of sufferers develop bilateral vestibular schwannomas. In a UK study of 183 individuals from 112 families we have previously shown a fairly similar disease course within families, but quite marked inter-familial variation. We have confirmed an increase in severity when the gene is inherited from an affected mother, but evidence that women are more severely affected than men is lacking. Age at onset of symptoms, of deafness and at diagnosis are identical for the entire dataset and for a comparison of 10 male/female sibling pairs. Only three out of 42 pregnancies in symptomatic women were accompanied by a reversible worsening in symptoms due to vestibular schwannomas. Of 328 consecutive cases of unilateral vestibular schwannoma, there was no significant difference in the sex ratio or size. There now appears to be little evidence for a female hormonal effect on vestibular schwannomas. However, females with type 2 neurofibromatosis have significantly more meningiomas.

Acoustic neuroma (schwannoma) surgery 1978-1990

A series of 151 patients with 154 acoustic schwannomas have been operated upon in Manchester Royal Infirmary by a joint Otological and Neurosurgical team, employing either the translabyrinthine or the suboccipital approach. The perioperative mortality rate was 3 per cent. Anatomical preservation of the facial nerve was achieved in 89 per cent of tumour removals and a good to normal functional result in 79 per cent of cases. Attempts at hearing preservation have been unsuccessful, largely because of the small number of patients in the series in whom useful hearing was present preoperatively. Complications included major brain stem ischaemia (1.2 per cent), CSF fistula (5 per cent) and facial dysaesthesia (7 per cent). The incidence of mortality and morbidity is directly related to tumour size and to the experience of the surgeons. A number of patients experienced an unusual type of post-operative dreamlike state which appeared to be a form of hypnagogic hallucination, and the possible neurophysiological mechanism responsible for this phenomenon is discussed. The continuing failure to attain the ideal of early diagnosis is lamented, and the importance of a flexible bidisciplinary surgical approach emphasized.