caa a22 4500 606216529 CHVBK 20210128101103.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s00701-014-2298-z doi (NATIONALLICENCE)springer-10.1007/s00701-014-2298-z Pathological characteristics of cyst formation following gamma knife surgery for arteriovenous malformation [Elektronische Daten] [Takashi Shuto, Saburo Yagishita, Shigeo Matsunaga] Background: The pathological characteristics of cyst development after gamma knife surgery (GKS) for arteriovenous malformation (AVM) were analysed. Method: Sixteen male and 12 female patients aged 17-67years (mean 31.3years) were retrospectively identified among 868 patients who underwent GKS for AVM at our hospital. The pathological characteristics of the reddish nodular lesion and chronic encapsulated expanding haematoma associated with cyst following GKS for AVM were examined. Results: Cyst was associated with chronic encapsulated expanding haematoma in 13, and with nodular lesion in 12 patients. The nidus volume at GKS was 0.1-36ml (median 6.0ml), and the prescription dose at the nidus margin was 18-25Gy (median 20Gy). Cyst formation was detected from 1.1 to 16years (mean 7.3years) after GKS. Seven of the 12 patients with nodular lesion underwent surgery. Ten of the 13 patients with expanding haematoma underwent surgical removal of expanding haematoma. Histological examination was possible in 17 cases. Dilated capillary vessels with wall damage such as hyalinisation and fibrinoid necrosis, marked protein exudation and haemorrhage were the most common findings. Brain parenchyma was observed among the dilated vessels in some cases. Structureless necrotic tissue was not evident. Conclusions: The present study suggests that enhanced nodular lesion on magnetic resonance imaging and chronic encapsulated expanding haematoma associated with cyst may have common aetiopathology caused by late radiation effects, mainly consisting of dilated capillary vessels with wall damage. Massive protein exudation from such damaged capillary vessels is important in cyst development. Springer-Verlag Wien, 2014 Arteriovenous malformation nationallicence Gamma knife nationallicence Radiosurgery nationallicence Complication nationallicence Cyst nationallicence Shuto Takashi Department of Neurosurgery, Yokohama Rosai Hospital, 3211 Kozukue-cho, Kouhoku-ku, 222-0036, Yokohama, Kanagawa, Japan aut Yagishita Saburo Department of Pathology, Kanagawa Rehabilitation Hospital, Atsugi, Kanagawa, Japan aut Matsunaga Shigeo Department of Neurosurgery, Yokohama Rosai Hospital, 3211 Kozukue-cho, Kouhoku-ku, 222-0036, Yokohama, Kanagawa, Japan aut Acta Neurochirurgica Springer Vienna 157/2(2015-02-01), 293-298 0001-6268 157:2<293 2015 157 701 https://doi.org/10.1007/s00701-014-2298-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00701-014-2298-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Shuto Takashi Department of Neurosurgery, Yokohama Rosai Hospital, 3211 Kozukue-cho, Kouhoku-ku, 222-0036, Yokohama, Kanagawa, Japan aut NATIONALLICENCE 700 1- Yagishita Saburo Department of Pathology, Kanagawa Rehabilitation Hospital, Atsugi, Kanagawa, Japan aut NATIONALLICENCE 700 1- Matsunaga Shigeo Department of Neurosurgery, Yokohama Rosai Hospital, 3211 Kozukue-cho, Kouhoku-ku, 222-0036, Yokohama, Kanagawa, Japan aut NATIONALLICENCE 773 0- Acta Neurochirurgica Springer Vienna 157/2(2015-02-01), 293-298 0001-6268 157:2<293 2015 157 701