Development of de novo cavernous hemangioma after radiosurgery for cavernous hemangioma.

We report a rare case of cavernous hemangioma (CH) which developed in adjacent location to a preexisting CH after gamma knife radiosurgery (GKRS). A 36-year-old woman underwent GKRS for a CH in the left lentiform nucleus. Three-and-half years after radiosurgery, MRI revealed a new CH in the left caudate nucleus. Surgical excision of the new lesion was performed. The pathological examination confirmed the diagnosis of CH. In radiosurgery for CH, it should be noted that a new CH may develop, which is likely to result from the interaction between radiation and predisposing factors of the patient.