The Genetics of Vestibular Schwannoma

A Large Residual Vestibular Schwannoma Following Incomplete Resection: A Case Report With Literature Review

Vestibular schwannomas (VSs), also known as acoustic neuromas, are benign, slow-growing tumors. If not detected early or treated appropriately, these tumors can lead to complications such as pressure on adjacent intracranial structures that can affect vital functions. The present report discusses a rare case of a residual VS in a 46-year-old female patient. The patient was a known case of left-sided VS who underwent partial excision of the tumor four years ago and had complete hearing loss on the left side since then. She reported to the clinic with progressive headaches and imbalance while walking. Magnetic resonance imaging of the brain revealed a large left residual VS compressing the brainstem and cerebellum, which was completely excised, and the patient did well postoperatively. Incomplete resection of VS carries a significant risk of tumor regrowth, necessitating the importance of complete resection with periodic follow-ups.

Vestibular Impairment in Patients with Vestibular Schwannoma: A Journey through the Pitfalls of Current Literature

Vestibular Schwannoma is the most common tumour of Ponto Cerebellar Angle and is capable of strongly impacting the patient's quality of life. In recent decades, the proposals for the management of the disease have multiplied, just as the diagnostic capacity has improved. While in the past, the primary objective was the preservation of the facial function, and subsequently also of the auditory function, the attention to the vestibular symptomatology, which appears to be one of the main indicators of deterioration of quality of life, is still unsatisfactory. Many authors have tried to provide guidance on the best possible management strategy, but a universally recognized guideline is still lacking. This article offers an overview of the disease and the proposals which have advanced in the last twenty years, evaluating their qualities and defects in a critical reading.

Epidemiology of vestibular schwannoma in the United States, 2004-2016

Background

Vestibular schwannomas (VS) are nonmalignant tumors of the eighth cranial nerve and are the most common nonmalignant nerve sheath tumor. This study provides the most comprehensive and current analysis of VS epidemiology in the United States.

Methods

Incidence data were obtained from the Central Brain Tumor Registry of the United States, from 2004 to 2016 for VS. Age-adjusted incidence rates (AAIRs), rate ratios (AAIRRs), and prevalence ratios (AAPRs) per 100 000 were analyzed by age, sex, race and ethnicity, and laterality. Additional analyses were performed to assess differences in treatment, laterality, and diagnostic confirmation.

Results

Incidence of VS was highest among adults (aged 65–74 years, AAIR: 3.18, 95% confidence interval [CI]: 3.15–3.25). However, there was a much higher distribution of bilateral tumors compared to unilateral in children aged 0–19 years (28.5% vs 1.0%, P < .001). VS incidence was highest among white non-Hispanics (AAIR:1.30, 95% CI: 1.29–1. 31) and lowest among black non-Hispanics. Incidence of radiographically confirmed VS increased from 2004 to 2016 (annual percent change: 1.64, 95% CI: 0.15–3.16, P = .03). For treatment, 40.1% received surgery, while only 23.7% received radiation. There were an estimated 44 762 prevalent cases of VS in 2016 (AAPR: 12.17, 95% CI: 12.06–12.29).

Conclusions

VS incidence and prevalence are highest among adults and white non-Hispanics. Bilateral VS was more common among children. There was an increase of radiographically confirmed VS over time. A higher proportion of patients received surgical treatment than radiotherapy. Population-based statistics provide healthcare professionals with vital information regarding disease burden and help improve patient care.

Case report of seminal vesical schwannoma treated with conservative strategy

RATIONALE

Schwannoma is a benign peripheral nerve sheath tumor composed of Schwann cells and caused by genetic mutation or deletion. It rarely occurs in seminal vesicles. The optimal therapic strategy for asymptomatic cases is still unclear.

PATIENT CONCERNS

A 42-year-old man presented no clinical symptoms. A mass in his left seminal vesicle was found incidentally in a computed tomography scan and transrectal ultrasound-guided biopsy revealed the mass was schwannoma.

DIAGNOSIS

The patient was diagnosed as schwannoma of the seminal vesicle with no significant extension to the surrounding tissues.

INTERVENTIONS

The patient underwent computed tomography or magnetic resonance imaging scans periodically to estimate the alteration of the lesion and further strategy.

OUTCOMES

After 20-month follow-up, computed tomography scans showed no significant alteration to the lesion and no clinical symptoms were reported by the patient.

LESSONS

Conservative strategy might be an effective treatment option for asymptomatic patients with seminal vesical schwannoma. The period of follow-up depends on the size of the tumor.

Therapy of Sporadic and NF2-Related Vestibular Schwannoma

Vestibular schwannoma (VS) is a benign primary brain tumor that occurs sporadic or as part of a genetic syndrome. The most common cause is the mutation of the NF2 tumor suppressor gene that is involved in the production of the protein merlin. Merlin plays a role in cell growth and cell adhesion. In patients with NF2, the VSs arise bilaterally and coincide with other brain tumors. In sporadic VS, the tumor is typically unilateral and does not coincide in combination with other tumors. MRI is the standard imaging technique and can be used to assess the size and aspect of the tumor as well as the progression of disease. The preferred management of large VS in both VS types is surgery with or without adjuvant radiation. The management for the medium- or small-sized VS includes wait and scan, radiotherapy and/or surgery. This choice depends on the preference of the patient and institutional protocols. The outcomes of surgical and radiotherapy treatments are improving due to progress in surgical equipment/approaches, advances in radiation delivery techniques and dose optimizations protocols. The main purpose of the management of VS is preserving function as long as possible in combination with tumor control.

RETRACTED: Brazilein induces apoptosis and G1/G0 phase cell cycle arrest by up-regulation of miR-133a in human vestibular schwannoma cells

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Given the comments of Dr Elisabeth Bik regarding this article “... the Western blot bands in all 400+ papers are all very regularly spaced and have a smooth appearance in the shape of a dumbbell or tadpole, without any of the usual smudges or stains. All bands are placed on similar looking backgrounds, suggesting they were copy/pasted from other sources, or computer generated”, the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.