[De novo formation of a cavernoma in association with a preformed venous malformation during immunosuppressive treatment].

We report the clinical course of a 48 year old woman, who underwent a cranial MRI-examination in 1995, which confirmed the diagnosis of encephalomyelitis disseminata, but also showed a left temporal venous malformation without evidence of prior hemorrhage. Three month after immunosuppressive treatment with Methotrexate in 1997 begun, first hemorrhage in the left temporal lobe occurred with de novo formation of a cavernoma in association to the known venous malformation. The lesion was totally removed after stereotactic guided craniotomy without any complication. The pathogenetic relationship of de novo cavernomas and associated venous malformations and the remarkable association with immunosuppressive treatment will be discussed.