[A case of retroperitoneal malignant peripheral nerve sheath tumor in a patient with neurofibromatosis].

We report a case of retroperitoneal malignant peripheral nerve sheath tumor (MPNST) in a patient with neurofibromatosis 1. A 42-year-old woman was admitted because of a palpable left abdominal mass. Her mother, son, and daughter had neurofibromatosis 1. Computed tomography and magnetic resonance imaging revealed a 73 x 76 mm retroperitoneal mass. We performed complete resection of the tumor, confirming the margin status by frozen section examination intraoperatively. The histopathological examination revealed MPNST. Although no further therapy was performed, she is alive with no evidence of disease 11 months after surgery.