Retroperitoneal neurofibrosarcoma in a patient with neurofibromatosis. 2: A case report and review of the literature.

Neurofibromatosis (NF) type I (NF1) is the most common familial cancer-predisposing syndrome in humans, while type 2 (NF2) accounts for an extremely small percentage of the total cases of NF. Tumors occurring in patients with NF1 are primarily peripheral neurofibromas, while NF2 patients present with central schwannomas. Malignant transformation has been described in NF1 patients; however, in NF2 the risk of malignant transformation is extremely rare. In this case report, the authors document a retroperitoneal neurogenic sarcoma occurring in a 20-year-old woman with NF2 (bilateral acoustic schwannomas, meningioma, and multiple intraspinal tumors).