Glioblastoma after AVM radiosurgery. Case report and review of the literature.
BACKGROUND
Stereotactic radiosurgery (SRS) is considered to be a relatively safe procedure in cerebral arteriovenous malformation management. There are very few reported cases of SRS-associated/induced malignancies.


METHODS
We show the case of a 21-year-old female who presented with a 21-mm(3) ruptured AVM in the right mesial frontocallosal region. Embolization and/or radiosurgery was proposed. She preferred radiosurgery. The AVM was treated with CyberKnife(®) SRS.


RESULTS
She presented behavior changes 6 years after SRS. MRI showed a right subcortical frontal lesion with increased perfusion, more consistent with high-grade glioma. The lesion's center was within the irradiated region of the previous SRS, having received an estimated radiation dose of 4 Gy. Pathological examination noted a hypercellular tumor showing astrocytic tumor cells with moderate pleomorphism in a fibrillary background, endothelial proliferation, and tumor necrosis surrounded by perinecrotic pseudopalisades. Numerous mitotic figures were seen. The appearances were those of glioblastoma, WHO grade IV, with neuronal differentiation. SRS-associated/-induced GBM after treatment of a large AM is exceptional. SRS-associated/-induced malignancies are mostly GBMs and occur on average after a latency of 9.4 years, within very low-dose peripheral regions as well as the full-dose regions; 33.3 % of patients were under 20 years at the time of SRS, and in 66 % the lesion treated was a vascular pathology.


CONCLUSIONS
Although it is unlikely that the risk of radiation-induced cancer will change the current standard of practice, patients must be warned of this potential possibility before treatment.
Service of Neurosurgery, University Hospital Centre "Mother Teresa", Kongresi i Manastirit, Nr. 210, Tirane, Albania.
Artur
A
Xhumari
Arben
A
Rroji
Eugen
E
Enesi
Teona
T
Bushati
Kita
K
Sallabanda Diaz
Mentor
M
Petrela
D001165:Arteriovenous Malformations / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D005909:Glioblastoma / Q000209:etiology*; D006801:Humans; D009381:Neoplasms, Radiation-Induced / Q000209:etiology*; D016634:Radiosurgery / Q000009:adverse effects*; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult