title: Extreme volume expansion of a vestibular schwannoma due to intratumoral hemorrhage after gamma knife radiosurgery.
abstract: A 48-year-old man with right hemi-facial palsy and cerebellar ataxia was referred to our hospital. Three years and 10 months earlier he had undergone gamma knife radiosurgery (GKRS) at the referring hospital for an 18 mm right vestibular schwannoma. Slight tumor enlargement had been observed on MRI performed at the referring hospital 3 years after the GKRS. On close follow-up after another 6 months an MRI showed an obvious enlargement of the tumor. An MRI on admission revealed an iso-intense mass lesion measuring 36 mm in maximum diameter at the right cerebellopontine angle. A two stage surgery was conducted using a retrosigmoid approach because bleeding from the tumor wall was difficult to control intraoperatively during the first operation. At the second operation, the majority of the tumor capsule had converted to necrotic tissue. A large hematoma cavity was present inside the tumor capsule which explained the rapid increase in size over a short period of time. Near total removal was achieved. Histopathological examination revealed massive intratumoral hemorrhage within a typical vestibular schwannoma with no malignancy. The complication of intratumoral hemorrhage is very rare and the utility of stereotactic radiation surgery/therapy, including GKRS, for vestibular schwannoma is well known. However, we must emphasize that careful follow-up is still required, even after several years.
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, 2-1-1 Tennodai, Tsukuba, Ibaraki 305-8576, Japan.
authors.forename: Shunichiro
authors.initials: S
authors.lastname: Miki
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, 2-1-1 Tennodai, Tsukuba, Ibaraki 305-8576, Japan. Electronic address: e-ishikawa@md.tsukuba.ac.jp.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Ishikawa
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, 2-1-1 Tennodai, Tsukuba, Ibaraki 305-8576, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, 2-1-1 Tennodai, Tsukuba, Ibaraki 305-8576, Japan.
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Akutsu
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, 2-1-1 Tennodai, Tsukuba, Ibaraki 305-8576, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Matsuda
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, 2-1-1 Tennodai, Tsukuba, Ibaraki 305-8576, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Sakamoto
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, 2-1-1 Tennodai, Tsukuba, Ibaraki 305-8576, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Matsumura
mesh_terms: D002524:Cerebellar Ataxia / Q000209:etiology; D002543:Cerebral Hemorrhage / Q000209:etiology / Q000628:therapy*; D005158:Facial Paralysis / Q000209:etiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009464:Neuroma, Acoustic / Q000150:complications* / Q000601:surgery*; D011183:Postoperative Complications / Q000628:therapy*; D016634:Radiosurgery / Q000009:adverse effects*; D016896:Treatment Outcome
keywords: Complication; Gamma knife surgery; Intratumoral bleeding; Regrowth; Vestibular schwannoma