title: Tumefactive cysts: a delayed complication following radiosurgery for cerebral arterial venous malformations.
abstract: We report five cases of symptomatic delayed cyst formation after radiosurgery for intracranial arterial venous malformations. Median time to discovery of the cysts following most recent radiosurgery was 59 months (range, 34-89 months). In all five patients, the radiation therapy-induced cysts exhibited tumefactive characteristics, including vasogenic edema, mass effect, and nodular enhancement. Despite these malignant features, these cystic lesions should be recognized as a benign complication of radiosurgery so that proper treatment (i.e., cystoperitoneal shunt surgery or excision) can be initiated.
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Whitney B
authors.initials: WB
authors.lastname: Edmister
authors.forename: John I
authors.initials: JI
authors.lastname: Lane
authors.forename: Julie R
authors.initials: JR
authors.lastname: Gilbertson
authors.forename: Robert D
authors.initials: RD
authors.lastname: Brown
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Pollock
mesh_terms: D000328:Adult; D001927:Brain Diseases / Q000175:diagnosis* / Q000209:etiology*; D003560:Cysts / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000009:adverse effects*; D013997:Time Factors