BACKGROUND: Gamma knife radiosurgery (GKRS) is an effective treatment for vestibular schwannomas with lower morbidity and mortality. However, malignant transformation associated with GKRS, although uncommon, has been reported in recent publications. METHODS: We describe a case presenting with malignant peripheral nerve sheath tumor (MPNST) at 8 years after GKRS after incomplete resections. RESULTS: The tumor appeared to be a typical benign schwannoma at the surgery preceding GKRS, and rapidly enlarged after long-term control, causing progressive neurological deterioration. Operative findings showed that the tumor was composed of two different components, and histopathology distinctively demonstrated MPNST and benign schwannoma. CONCLUSIONS: The coexistence of benign and malignant components might indicate that the present MPNST had arisen from the benign schwannoma by transformation in association with GKRS.
BACKGROUND: Gamma knife radiosurgery (GKRS) is an effective treatment for vestibular schwannomas with lower morbidity and mortality. However, malignant transformation associated with GKRS, although uncommon, has been reported in recent publications. METHODS: We describe a case presenting with malignant peripheral nerve sheath tumor (MPNST) at 8 years after GKRS after incomplete resections. RESULTS: The tumor appeared to be a typical benign schwannoma at the surgery preceding GKRS, and rapidly enlarged after long-term control, causing progressive neurological deterioration. Operative findings showed that the tumor was composed of two different components, and histopathology distinctively demonstrated MPNST and benign schwannoma. CONCLUSIONS: The coexistence of benign and malignant components might indicate that the present MPNST had arisen from the benign schwannoma by transformation in association with GKRS.
Authors: Lawrence J Sheplan Olsen; Lizbeth Robles Irizarry; Samuel T Chao; Robert J Weil; Amir H Hamrahian; Betul Hatipoglu; John H Suh Journal: Pituitary Date: 2012-06 Impact factor: 4.107