Intracranial sarcoma in a patient with neurofibromatosis type 2 treated with gamma knife radiosurgery for vestibular schwannoma.

OBJECTIVE: To discuss the possible relationship between stereotactic radiation therapy and the development of a meningosarcoma. STUDY DESIGN: Retrospective case review. PATIENT: A 19-year-old woman with bilateral vestibular schwannomas (neurofibromatosis type 2). One large tumor was removed totally by the translabyrinthine approach; the other smaller tumor was treated with stereotactic radiation (SRT). Six years after SRT, a malignant tumor (meningosarcoma) developed at the exact site of radiation. The patient subsequently died of this tumor. OUTCOME MEASURE: On the basis of literature surveys, the possibility and risk of postirradiation neoplasia after SRT is discussed. Furthermore, the possible causal association between SRT and the development of the meningosarcoma in this case is evaluated. CONCLUSION: On the basis of statistical considerations, the development of the reported mesenchymal sarcoma was most likely caused by the stereotactic radiation therapy.