schwannoma
Pronunciation: SHWAN-oh-mah
A benign nerve sheath tumor arising from Schwann cells, most commonly affecting cranial nerve VIII (acoustic neuroma).
Full Definition
A schwannoma is a benign tumor originating from Schwann cells that form the myelin sheath around peripheral nerves. These tumors are characterized by alternating areas of high cellularity (Antoni A) and low cellularity (Antoni B) with distinctive Verocay bodies. Most commonly presenting as acoustic neuromas affecting the eighth cranial nerve, schwannomas can occur anywhere along peripheral nerves. They are typically encapsulated and can be surgically resected with preservation of nerve function in many cases.
Usage
Usage note: Distinguish from neurofibroma, which lacks encapsulation and shows different histological patterns.
In Context
- "The MRI findings were consistent with a vestibular schwannoma showing the characteristic cerebellar pontine angle mass." — Radiology report
- "Histological examination revealed typical Antoni A and Antoni B patterns confirming the diagnosis of schwannoma." — Pathology report