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Updated: Jun 15, 2026

Primary Culture of Human Vestibular Schwannomas
Published on: July 20, 2014
"Flow-void" sign at MR imaging: a rare finding of extracranial head and neck schwannomas
Hiroki Kato1, Masayuki Kanematsu, Keisuke Mizuta
1Department of Radiology, Gifu University School of Medicine, Gifu, Japan. hkato@gifu-u.ac.jp
Abstract:
The authors present two cases of extracranial head and neck schwannomas that exhibited the "flow-void" sign at MR imaging. In the described cases, MR images showed intratumoral signal voids, which corresponded to dilated vessels. Dynamic contrast-enhanced CT also demonstrated dilated vessels within the tumors on the arterial phase and tumor parenchymal enhancement on the delayed phase. Histopathologic examinations of excised specimens revealed thin-walled, dilated abnormal vessels with or without hyaline degeneration. Schwannoma should be considered when MR images demonstrate the "flow-void" sign in extracranial head and neck tumors.
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