In standard of care regularly planned surgery, tissue will be obtained from patients who are suspicious for having vestibular Schwannoma (on MRI). The tissue that remains after the pathologist gathered sufficient for analysis, the remaining tissue is used for creating tumour stem cell organoids.

This project constitutes scientific research since the presence of tumor stem cells has not been shown in schwannoma before. Secondly the organoid model has not yet been described for VSs. The correlation between effect in schwannoma organoids and in patients has to be evaluated but can proof to be very valuable since it has been shown in a number of tumors. The tumor tissue will be acquired during regularly planned surgery. The tissue that is used is what is left after sufficient material has been sent to the pathologist to make the diagnosis. So the tissue that is used is removed routinely during surgery, but instead of banking it at the pathology department, it is used for the research project. Blood samples that can be used to compare normal DNA to tumor cells DNA will be acquired from central lines that are routinely placed during these procedures, so no additional interventions will be done in acquiring the tissue and blood for this study.

Inclusion Criteria:

• MRI with suspicion for vestibular schwannoma
• Indication for surgery in the skull base committee
• 18 years or older

Exclusion Criteria:

• Refusal to participate
• Younger than 18 years
• Incapacitated

Patients with a supsicion for vestibular schwannoma on an MRI for which surgery was indicated (approximately 10 per year in Maastricht).